Short-chain fatty acids from the socks and feet of subjects either with strong foot odour or with weak or no foot odour were extracted with ethyl ether, and then analysed by gas chromatography/mass spectrometry (GC/MS). Short chain fatty acids were found in greater amounts from those subjects with strong foot odour. Iso-valeric acid was present in all the subjects with foot odour but was not detected in those without. Olfactory evaluations of the various short-chain fatty acid solutions were in agreement with the GC/MS analyses. By incubating sweat and lipid from subjects with strong foot odour, we succeeded in reproducing the foot malodour. GC/MS analyses of reproduced foot odour revealed that short-chain fatty acids were present in a similar composition to that found in vivo.

These results indicate that the morphology and areas of sagging in male faces are similar to those in females in the cheek, but sagging at the lower eyelid is more severe in males after middle age. Furthermore, the dermal elasticity of male facial skin decreased with age similar to that of females, and may therefore be associated with the sagging formation in male faces.

We investigated the structural ordering of stratum corneum (SC) lipid by means of electron paramagnetic resonance (EPR) slow-tumbling simulation in conjunction with spin probe studies. The SC of human mid-volar forearm was stripped consecutively from three to six times. The EPR probe method detected a characteristic peak of sebaceous matter in the first SC stripping. The order parameter values obtained by the slow-tumbling simulation (S(0)) showed significant differences between each layer compared with those indicated by the conventional order parameter (S) using hyperfine couplings. Although the conventional S values were in the range of 0.56 (outermost layer) to 0.61 (bottom layer), the S(0) values by the simulation changed from 0.22 to 0.96. The present results suggest that the structural ordering of the outermost SC layer is less tight, whereas the structure of inner layers becomes more rigid. Therefore, we concluded that the EPR probe method recognizes sebaceous matters, whereas EPR in conjunction with the simulation allows quantitative evaluation of SC lipid ordering in relation to skin depth.

No abstract

Skin radiance is an important determinant of skin beauty that almost all women desire. However, the optical reflection characteristics that create the perception of skin radiance are not fully established. The skin properties associated with radiance have received little attention. The aim of this study is to examine the optical characteristics of skin radiance and its associations with other skin properties. We established a method for evaluating skin radiance by measuring the intensities of specular and diffuse reflection components and investigated their age dependence. The results indicated high levels of both specular and diffusion reflection in radiant skin. An age-dependent decrease and a slight increase of diffuse and specular reflection, respectively, were found in the group aged 60 79 years. We examined the number of ridges and surface roughness of corneocyte cells. High specular reflectance was associated with low numbers of the ridges and surface roughness values of corneocyte cells. Because well-conditioned skin shows high numbers of ridges, smoothing the corneocyte cell surface effectively enhances the specular skin reflection value.