ArticleInvestigative ophthalmology & visual science2012
Mass spectrometric identification of phospholipids in human tears and tear lipocalin.
Article in Investigative ophthalmology & visual science, 2012. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 28 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
28 citing papers in PubMed, 76 citations in OpenAlex.
- Diurnal Variation of Tear and Meibum Lipids in Healthy Subjects.Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists) · 2026Article
- Article
- Metabolomic changes in tear fluid following zinc biofortification in the BiZiFED nutritional study: a feasibility study.Frontiers in molecular biosciences · 2024Article
- Effect of Model Tear Film Lipid Layer on Water Evaporation.Investigative ophthalmology & visual science · 2023Article
- Nonpolar Lipids Contribute to Midday Fogging During Scleral Lens Wear.Investigative ophthalmology & visual science · 2023Article
- Antimicrobial Tear Lipids in the Ocular Surface Defense.Frontiers in cellular and infection microbiology · 2022Review
- Lipocalin-1 is the acceptor protein for phospholipid transfer protein in tears.Biochemical and biophysical research communications · 2021Article
- Tear Lipocalin and Lipocalin-Interacting Membrane Receptor.Frontiers in physiology · 2021Article
- Evidence for Phospholipids on the Surface of Human Tears.Investigative ophthalmology & visual science · 2020Article
- Article
- Ellipsometry of human tears.The ocular surface · 2019Article
- Metabolomics and Age-Related Macular Degeneration.Metabolites · 2018Review
- Ligand binding complexes in lipocalins: Underestimation of the stoichiometry parameter (n).Biochimica et biophysica acta. Proteins and proteomics · 2018Article
- Novel Nano-Liposome Formulation for Dry Eyes with Components Similar to the Preocular Tear Film.Polymers · 2018Article
- Interaction of ceramides and tear lipocalin.Biochimica et biophysica acta. Molecular and cell biology of lipids · 2018Article
- Dry eye syndrome: developments and lifitegrast in perspective.Clinical ophthalmology (Auckland, N.Z.) · 2018Review
- Relevance of Lipid-Based Products in the Management of Dry Eye Disease.Journal of ocular pharmacology and therapeutics : the official journal of the Association for Ocular Pharmacology and Therapeutics · 2017Review
- TFOS DEWS II Tear Film Report.The ocular surface · 2017Review
- Surface Properties of Squalene/Meibum Films and NMR Confirmation of Squalene in Tears.International journal of molecular sciences · 2015Article
- Allergen ligands in the initiation of allergic sensitization.Current allergy and asthma reports · 2014Article
Corrections and comments
- Erratum issued
Authors and funding
2 authors at 2 institutions in 1 country.
Funding
Abstract
purposeThe purpose of this article was to identify by mass spectrometry phosphocholine lipids in stimulated human tears and determine the molecules bound to tear lipocalin or other proteins.
methodsTear proteins were separated isocratically from pooled stimulated human tears by gel filtration fast performance liquid chromatography. Separation of tear lipocalin was confirmed by SDS tricine gradient PAGE. Protein fractions were extracted with chloroform/methanol and analyzed with electrospray ionization MS/MS triple quadrupole mass spectrometry in precursor ion scan mode for select leaving groups. For quantification, integrated ion counts were derived from standard curves of authentic compounds of phosphatidylcholine (PC) and phosphatidylserine.
resultsLinear approximation was possible from integration of the mass spectrometrically obtained ion peaks at 760 Da for the PC standard. Tears contained 194 ng/mL of the major intact PC (34:2), m/z 758.6. Ten other monoisotopic phosphocholines were found in tears. A peak at 703.3 Da was assigned as a sphingomyelin. Four lysophosphatidylcholines (m/z 490-540) accounted for about 80% of the total integrated ion count. The [M+H](+) compound, m/z 496.3, accounted for 60% of the signal intensity. Only the tear lipocalin-bearing fractions showed phosphocholines (104 ng/mL). Although the intact phospholipids bound to tear lipocalin corresponded precisely in mass and relative signal intensity to that found in tears, we did not identify phosphocholines between m/z 490 and 540 in any of the gel-filtration fractions.
conclusionsPhospholipids, predominantly lysophospholipids, are present in tears. The higher mass intact PCs in tears are native ligands of tear lipocalin.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.