A comparison of pulsed ultrasound, radiography and micrometer screw gauge in the measurement of skin thickness

Test systems for the determination of glucocorticoid receptor ligand induced skin atrophy

Topical glucocorticoids are highly anti-inflammatory effective but limited by their side effect potential, with skin atrophy being the most prominent one. Thus, determining the atrophogenic potential of novel compounds targeting the glucocorticoid receptor is important. Significant progress in the understanding of glucocorticoid receptor mediated molecular action has been made providing the basis for novel glucocorticoid receptor ligands with a potentially superior effect/side effect profile. Such compounds, however, need to be tested. The present gold standard for the reliable prediction of glucocorticoid induced skin atrophy are still in vivo models, however, in vitro models may replace them to some extent in the future. Indeed, advances in technologies to determine the atrophogenic potential of compounds in vitro has been made recently and promising novel test models like the human full thickness skin models are emerging. Their full predictive value, however, needs to be further evaluated. Currently, a screening approach starting with a combination of several in vitro test systems followed by subsequent testing of the most promising compounds in rodent models is recommended prior entering clinical studies with selected development compounds.

Glucocorticoid therapy-induced skin atrophy

Glucocorticoids (GCs) are highly effective for the topical treatment of inflammatory skin diseases. Their long-term use, however, is often accompanied by severe and partially irreversible adverse effects, with atrophy being the most prominent limitation. Progress in the understanding of GC-mediated molecular action as well as some advances in technologies to determine the atrophogenic potential of compounds has been made recently. It is likely that the detailed mechanisms of GC-induced skin atrophy will be discovered and in vitro models for the reliable prediction of atrophy will be established in the foreseeable future. This knowledge will not only facilitate safety profiling of established drugs but will also foster further drug discovery by improving compound characterization processes. New insights into GC modes of action will guide optimization strategies aiming at novel GC receptor ligands with improved effect/side effect profile.

High frequency, high resolution B-scan ultrasound in the assessment of skin tumours

Sixteen skin tumours and one BCG vaccination granuloma were examined by 20-MHz B-scan ultrasound. Images were compared with closely matched histological sections of excised lesions. The correlation between histology and ultrasound was excellent for maximum tumour depth measurements (r = 0.96, P < 0.0001), but less good for maximum width (r = 0.84, P < 0.0001) because of the elastic contraction of tissue at excision. Architectural detail of lesions on histological sections corresponded well with that on ultrasound images. There was a good correlation for heterogeneity (collagen distribution vs. echo pattern (r = 0.86, P < 0.0001)), and between collagen content and echogenicity of lesions (r = 0.69, P < 0.003). Strong correlations were also obtained for echogenicity vs. spacing of collagen bundles (r = -0.65, P < 0.005), echogenicity vs. collagen bundle size (r = 0.58, P < 0.02), and echogenicity vs. cellularity (r = -0.68, P < 0.003). Results for dermatofibroma were atypical, due to paradoxical low internal echogenicity and increased echo absorption. B-scanning is a reliable non-invasive method for assessing tumour dimensions, and has potential for the study of tumour characteristics for diagnostic purposes.