title: Black magic and EPR oximetry: from lab to initial clinical trials.
abstract: EPR oximetry is a technique that can make repeated non-invasive measurements of the PO2 in tissues. To extend the application of EPR oximetry to humans, India ink is the probe of choice because appropriate India inks have EPR signals whose line widths are sensitive to changes in oxygen concentrations, and, most importantly, India ink already has been used extensively in humans as a marker in the skin, lymphatics, various organs during surgery, tumors, and for decoration as tattoos. We have developed an India ink that has good sensitivity to oxygen, high stability in tissues, good signal intensity, and minimal toxicity. In this article we describe the various properties of this India ink, results obtained from our animal experiments, and our first preliminary clinical results, which are part of the first systematic clinical use of EPR oximetry. The clinical results indicate that it is possible to do repeated measurements over several months and probably years after the injection of the ink, indicating that long-term follow-up studies are feasible. We are very encouraged with these results and are confident that EPR oximetry using India ink will be a non-invasive, fast, and reliable technique for pO2 measurements in clinical studies.
authors.forename: Nadeem
authors.initials: N
authors.lastname: Khan
authors.forename: Huagang
authors.initials: H
authors.lastname: Hou
authors.forename: Patrick
authors.initials: P
authors.lastname: Hein
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Comi
authors.forename: Jay C
authors.initials: JC
authors.lastname: Buckey
authors.forename: Oleg
authors.initials: O
authors.lastname: Grinberg
authors.forename: Ildar
authors.initials: I
authors.lastname: Salikhov
authors.forename: Shi Y
authors.initials: SY
authors.lastname: Lu
authors.forename: Hermine
authors.initials: H
authors.lastname: Wallach
authors.forename: Harold M
authors.initials: HM
authors.lastname: Swartz
mesh_terms: D000818:Animals; D002244:Carbon; D003238:Connective Tissue / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D006801:Humans; D066298:In Vitro Techniques; D007281:Ink; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism; D010092:Oximetry / Q000379:methods*; D010100:Oxygen / Q000032:analysis / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: C028433:chinese ink; D002244:Carbon; D010100:Oxygen