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Biomedical subjects

J R Bond

Publications and source records attributed to J R Bond.

25 records · Page 2Linked to original sources

Takayasu's arteritis. Carotid duplex sonographic appearance, including color Doppler imaging.

Takayasu's arteritis (also known as pulseless disease, aortoarteritis, and aortic arch syndrome) is a chronic inflammatory arteriopathy that affects the aorta and its main branches as well as the pulmonary arteries. We report the carotid duplex sonographic findings of Takayasu's arteritis in three patients. Takayasu's arteritis can be suspected by noting a long segment of diffuse, homogeneous, circumferential vessel wall thickening in the proximal common carotid artery, resulting in narrowing of the lumen. The internal and external carotid arteries are normal.

Adult↗

Limitations of hairless mouse skin as a model for in vitro permeation studies through human skin: hydration damage.

Hairless mouse skin currently provides a popular model membrane for studies in human percutaneous absorption. Although some similarities between the two skin types have been demonstrated, the effects of prolonged hydration on hairless mouse skin have not previously been rigorously examined. We have measured in vitro the effects of hydration at 31 degrees C on the permeabilities of hairless mouse skin and human abdominal and scalp skin to a model polar compound (water) and a lipid material (hexanol). The permeability of hairless mouse skin rose dramatically, especially to water (fiftyfold increase), whereas the human skin was more stable. We also compared the effects of stripping the stratum corneum with the effects of 8-d hydration for hairless mouse and human abdominal skin. Hydration of hairless mouse skin was as effective as tape-stripping in eliminating the stratum corneum barrier, whereas stripping human skin was far more damaging than hydration, suggesting that prolonged hydration mechanically disrupted mouse skin but not human skin. Histological examination of fresh and hydrated tissues confirmed this suggestion. We therefore recommend that hairless mouse skin is not used as a model for human tissue during in vitro permeation studies under conditions of long-term hydration, i.e., greater than three days.

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Hairless mouse skin is limited as a model for assessing the effects of penetration enhancers in human skin.

The permeability coefficient of 5-fluorouracil through human abdominal and hairless mouse skins was used as an indicator of the relative effects of 12-h pretreatment of the skins with either penetration-enhancer mixtures [including laurocapram (Azone), decylmethylsulfoxide, oleic acid, and propylene glycol] or saline (control). After treatment with saline, fluxes of 5-fluorouracil through the two skin types were similar, but the mouse skin showed exaggerated responses to all the penetration-enhancer formulations. There was no consistent relationship between enchancer effects on the two skin types, and we conclude that the hairless mouse model should not be used to predict the effects of penetration enhancers in human skin. After treatment with saline, hairless mouse skin sharply increased in permeability after approximately 50 h hydration, suggesting that the stratum corneum had started to disrupt, whereas the flux through human skin remained unchanged.

Animals↗