Measurement of Collagen Cross-Links from Tissue Samples by Mass Spectrometry

2019 ◽  
pp. 79-93 ◽  
Author(s):  
Amar Joshi ◽  
Amna Zahoor ◽  
Alberto Buson
Keyword(s):  
Mass Spectrometry ◽  
Tissue Samples ◽  
Cross Links

scholarly journals Histopathological Evaluation of the Exposure by Cyanobacteria Cultive Containing [d-Leu1]Microcystin-LR on Lithobates catesbeianus Tadpoles

Toxins ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 318 ◽  
Author(s):  
Osmindo Rodrigues Pires Júnior ◽  
Natiela de Oliveira ◽  
Renan Bosque ◽  
Maria Nice Ferreira ◽  
Veronica Morais Aurélio da Silva ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Microcystis Aeruginosa ◽  
Intestinal Tract ◽  
Mass Spectrometry Analysis ◽  
Clean Water ◽  
Tissue Samples ◽  
Spectrometry Analysis ◽  
Lithobates Catesbeianus ◽  
Histopathological Evaluation ◽  
Unialgal Culture

This study evaluated the effects of [d-Leu1]Microcystin-LR variant by the exposure of Lithobates catesbeianus tadpole to unialgal culture Microcystis aeruginosa NPLJ-4 strain. The Tadpole was placed in aquariums and exposed to Microcystis aeruginosa culture or disrupted cells. For 16 days, 5 individuals were removed every 2 days, and tissue samples of liver, skeletal muscle, and intestinal tract were collected for histopathology and bioaccumulation analyses. After exposure, those surviving tadpoles were placed in clean water for 15 days to evaluate their recovery. A control without algae and toxins was maintained in the same conditions and exhibited normal histology and no tissue damage. In exposed tadpoles, samples were characterized by serious damages that similarly affected the different organs, such as loss of adhesion between cells, nucleus fragmentation, necrosis, and hemorrhage. Samples showed signs of recovery but severe damages were still observed. Neither HPLC-PDA nor mass spectrometry analysis showed any evidence of free Microcystins bioaccumulation.

scholarly journals Determination of CYP450 Expression Levels in the Human Small Intestine by Mass Spectrometry-Based Targeted Proteomics

2021 ◽  
Vol 22 (23) ◽  
pp. 12791
Author(s):  
Alexia Grangeon ◽  
Valérie Clermont ◽  
Azemi Barama ◽  
Fleur Gaudette ◽  
Jacques Turgeon ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Small Intestine ◽  
Protein Expression ◽  
Mrna Levels ◽  
Targeted Proteomics ◽  
Tissue Samples ◽  
Human Organ ◽  
Expression Levels ◽  
Protein Levels ◽  
Human Small Intestine

The human small intestine can be involved in the first-pass metabolism of drugs. Under this condition, members of the CYP450 superfamily are expected to contribute to drug presystemic biotransformation. The aim of this study was to quantify protein expression levels of 16 major CYP450 isoforms in tissue obtained from nine human organ donors in seven subsections of the small intestine, i.e., duodenum (one section, N = 7 tissue samples), jejunum (three subsections (proximal, mid and distal), N = 9 tissue samples) and ileum (three subsections, (proximal, mid and distal), N = 9 tissue samples), using liquid chromatography tandem mass spectrometry (LC-MS/MS) based targeted proteomics. CYP450 absolute protein expression levels were compared to mRNA levels and enzyme activities by using established probe drugs. Proteins corresponding to seven of sixteen potential CYP450 isoforms were detected and quantified in various sections of the small intestine: CYP2C9, CYP2C19, CYP2D6, CYP2J2, CYP3A4, CYP3A5 and CYP4F2. Wide inter-subject variability was observed, especially for CYP2D6. CYP2C9 (p = 0.004) and CYP2C19 (p = 0.005) expression levels decreased along the small intestine. From the duodenum to the ileum, CYP2J2 (p = 0.001) increased, and a trend was observed for CYP3A5 (p = 0.13). CYP3A4 expression was higher in the jejunum than in the ileum (p = 0.03), while CYP4F2 expression was lower in the duodenum compared to the jejunum and the ileum (p = 0.005). CYP450 protein levels were better correlated with specific isoform activities than with mRNA levels. This study provides new data on absolute CYP450 quantification in human small intestine that could improve physiologically based pharmacokinetic models. These data could better inform drug absorption profiles while considering the regional expression of CYP450 isoforms.

scholarly journals Cryo-Gel embedding compound for renal biopsy biobanking

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Malou L. H. Snijders ◽  
Marina Zajec ◽  
Laurens A. J. Walter ◽  
Remco M. A. A. de Louw ◽  
Monique H. A. Oomen ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Cutting Temperature ◽  
Renal Tissue ◽  
Tissue Samples ◽  
Normal Spleen ◽  
Renal Biopsies ◽  
Optimal Cutting Temperature ◽  
Embedding Medium ◽  
Rna And Dna

Abstract Optimal preservation and biobanking of renal tissue is vital for good diagnostics and subsequent research. Optimal cutting temperature (OCT) compound is a commonly used embedding medium for freezing tissue samples. However, due to interfering polymers in OCT, analysis as mass spectrometry (MS) is difficult. We investigated if the replacement of OCT with Cryo-Gel as embedding compound for renal biopsies would enable proteomics and not disturb other common techniques used in tissue diagnostics and research. For the present study, fresh renal samples were snap-frozen using Cryo-Gel, OCT and without embedding compound and evaluated using different techniques. In addition, tissue samples from normal spleen, skin, liver and colon were analyzed. Cryo-Gel embedded tissues showed good morphological preservation and no interference in immunohistochemical or immunofluorescent investigations. The quality of extracted RNA and DNA was good. The number of proteins identified using MS was similar between Cryo-Gel embedded samples, samples without embedding compound and OCT embedded samples. However, polymers in the OCT disturbed the signal in the MS, while this was not observed in the Cryo-Gel embedded samples. We conclude that embedding of renal biopsies in Cryo-Gel is an excellent and preferable alternative for OCT compound for both diagnostic and research purposes, especially in those cases where proteomic analysis might be necessary.

scholarly journals Quantitation of neonicotinoid insecticides, plus qualitative screening for other xenobiotics, in small-mass avian tissue samples using UHPLC high-resolution mass spectrometry

2019 ◽  
Vol 31 (3) ◽  
pp. 399-407 ◽  
Author(s):  
Michael S. Filigenzi ◽  
Emily E. Graves ◽  
Lisa A. Tell ◽  
Karen A. Jelks ◽  
Robert H. Poppenga
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Analytical Method ◽  
High Resolution Mass Spectrometry ◽  
Small Body ◽  
Screening Process ◽  
Tissue Samples ◽  
High Resolution Mass ◽  
Relative Standard ◽  
Resolution Mass

We developed and validated a liquid chromatography–high-resolution mass spectrometry (LC-HRMS) analytical method for quantitatively measuring pesticide concentrations in small-body avian tissue samples using homogenized 1–2-d-old chicken carcasses as the test matrix. We quantified the following key insecticides: sulfoxaflor (sulfoximine class) and the neonicotinoids dinotefuran, nitenpyram, thiamethoxam, acetamiprid, thiacloprid, clothianidin, and imidacloprid. We used fortified chick carcass samples to validate method accuracy (80–125% recoveries), precision (<20% relative standard deviation), and sensitivity (≤1.2 ppb) for these targeted analytes. This method also uses full-scan, high-resolution MS to screen for the presence of a wide variety of other xenobiotics in bird carcasses. The utility of our screening process was demonstrated by the detection of carbaryl in some samples. This sensitive LC-HRMS analytical method for insecticide detection in a matrix of homogenized carcass is ideal for evaluating small birds for insecticide exposure. This novel whole-carcass method may allow for research studies of small-bodied, free-ranging avian species, and could provide insight regarding their exposure to multiple classes of environmental contaminants.

Determination of Pyrantel in Swine Liver by Flame Ionization Gas Chromatography and Confirmation by Gas Chromatography /Mass Spectrometry

1990 ◽  
Vol 73 (6) ◽  
pp. 883-886
Author(s):  
Susan S.C Tai ◽  
Nancy Cargile ◽  
Charlie J Barnes ◽  
Philip Kijak
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Internal Standard ◽  
Gas Chromatography Mass Spectrometry ◽  
Tissue Samples ◽  
Flame Ionization ◽  
Chromatography Mass Spectrometry ◽  
Ionization Method ◽  
Swine Liver

Abstract During an evaluation of the gas chromatography/mass spectrometry (GC/MS) confirmatory procedure of Lynch and Bartoluccl for pyrantel residues in swine tissues, we developed a GC flame Ionization method for quantltatlng pyrantel residues In extracts of swine liver. The method was subjected to trial principally In the laboratories of Biospherics, Inc., using control liver, fortified control liver, and Incurred liver tissue samples. Although the method does not meet all of the current Food and Drug Administration criteria, it compares favorably to the official determinative method. Portions of the same extract can be used for quantitation and for GC/MS confirmation, true recoveries appear to be slightly higher, and an internal standard Is not required. The precision of this method equals or exceeds that of the official determinative method.

scholarly journals An image formation model for Secondary Ion Mass Spectrometry imaging of biological tissue samples

2010 ◽  
Vol 257 (4) ◽  
pp. 1267-1275 ◽  
Author(s):  
Gaia Volandri ◽  
Luca Menichetti ◽  
Marco Matteucci ◽  
Claudia Kusmic ◽  
Marco Consumi ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Biological Tissue ◽  
Mass Spectrometry Imaging ◽  
Secondary Ion Mass Spectrometry ◽  
Image Formation ◽  
Formation Model ◽  
Tissue Samples ◽  
Ion Mass Spectrometry ◽  
Secondary Ion

scholarly journals Structure elucidation of colibactin and its DNA cross-links

Science ◽  
2019 ◽  
Vol 365 (6457) ◽  
pp. eaax2685 ◽  
Author(s):  
Mengzhao Xue ◽  
Chung Sub Kim ◽  
Alan R. Healy ◽  
Kevin M. Wernke ◽  
Zhixun Wang ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Mass Spectrometry ◽  
Cell Biology ◽  
Structure Elucidation ◽  
Isotope Labeling ◽  
Tandem Mass ◽  
Physiological Effects ◽  
Human Gut ◽  
Structural Assignment ◽  
Cross Links

Colibactin is a complex secondary metabolite produced by some genotoxic gut Escherichia coli strains. The presence of colibactin-producing bacteria correlates with the frequency and severity of colorectal cancer in humans. However, because colibactin has not been isolated or structurally characterized, studying the physiological effects of colibactin-producing bacteria in the human gut has been difficult. We used a combination of genetics, isotope labeling, tandem mass spectrometry, and chemical synthesis to deduce the structure of colibactin. Our structural assignment accounts for all known biosynthetic and cell biology data and suggests roles for the final unaccounted enzymes in the colibactin gene cluster.

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