The measurement of @entity4095 in vivo using EPR has some features which have already led to very useful applications and this approach is likely to have increasingly wide and effective use. It is based on the effect of @entity26 on EPR spectra which provides a sensitive and accurate means to measure @entity4095 quantitatively. The development of @entity26 -sensitive paramagnetic materials which are very stable, combined with instrumental developments, has been crucial to the in vivo applications of this technique. The physical basis and biological applications of in vivo EPR oximetry are reviewed, with particular emphasis on the use of EPR spectroscopy at 1 GHz using particulate paramagnetic materials for the repetitive and non-invasive measurement of @entity4095 in tissues. In vivo EPR has already produced some very useful results which have contributed significantly to solving important biological problems. The characteristics of EPR oximetry which appear to be especially useful are often complementary to existing techniques for measuring @entity26 in tissues. These characteristics include the capability of making repeated measurements from the same site, high sensitivity to low levels of @entity26 , and non-invasive options. The existing techniques are especially useful for studies in small animals, where the depth of measurements is not an overriding issue. In larger animals and potentially in @entity1 subjects, non-invasive techniques seem to be immediately applicable to study phenomena very near the surface (within 10 mm) while invasive techniques have some very promising uses. The clinical uses of EPR oximetry which seem especially promising and likely to be undertaken in the near future are long-term monitoring of the status and response to treatment of @entity1095 and optimizing @entity5 therapy by enabling it to be modified on the basis of the @entity4095 measured in the @entity5 .

The measurement of XXXX in vivo using EPR techniques.

@entity1 :: ('9606', 'Species') :: ['human'] @entity1095 :: ('MESH:D016491', 'Disease') :: ['peripheral vascular disease'] @entity5 :: ('MESH:D009369', 'Disease') :: ['cancer', 'tumour'] @entity26 :: ('MESH:D010100', 'Chemical') :: ['oxygen'] @entity4095 :: ('MESH:C093415', 'Chemical') :: ['pO2']
@entity26 :: (MESH:D010100,Chemical) :: ['oxygen']
