1992 Fiscal Year Final Research Report Summary
Development of integrated methods for the evaluation of water-holding capacity of the stratum corneum based on bioengineering techniques
| Project/Area Number |
02557044
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Dermatology
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
TAGAMI H. Tohoku Univ. Sch. of Med. Dept. of Dermat Prof., 医学部, 教授 (60026911)
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| Co-Investigator(Kenkyū-buntansha) |
SUETAKE T. Tohoku Univ. School of Med. Dept. of Dermat. Assistant, 附属病院皮膚科, 助手 (60226397)
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| Project Period (FY) |
1990 – 1992
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| Keywords | Aging / atopic dermatitis / hydration / photoaging / stratum corneum / water |
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| Research Abstract |
Normal stratum corneum can maintain sufficient amounts of water to keep the skin surface soft and flexible even in a dry environment. In contrast, pathologic stratum corneum which lacks water-holding capacity develops scales and cracking on the skin surface even under ordinary ambient conditions. So far we have developed a non-invasive high frequency method to evaluate the hydration state of the skin surface.
In the present study, we have assessed the functional state of the stratum corneum of various skin, by integrating the results obtained by other evaluation methods such as measurements of transepidermal water loss, analysis of superficial desquamating layers, the cell layer number of stratum corneum, amino acid content and elasticity as well as the skin surface morphology visualized by video microscope,.
1. Neonatal skin is dry, because its stratum corneum which has been immersed in amniotic fluids is deficient in water-holding capacity.
2. Non-lesional skin of the patients with atopic dermatitis shows dryness, atopic xerosis. It stratum corneum is deficient in water-holding capacity and the amounts of amino acids that bind water in the stratum corneum is significantly lower in atopic xerosis than in normal controls. Evaluation of the various functional aspects of the stratum corneum indicates that atopic xerosis is a mind inflammatory skin accompanied by shortened turnover time and deficient barrier function of the stratum corneum.
3. The skin of elderly people tends to become dry in winter to develop the change of scnile xerosis. Simple photoaging does not enhance such a tendency and it represents the change of intrinsic aging of the skin.
4. Topical application of retinoic acid or oral intake of etretinate induce desquamation of the stratum corneum to decrease its water-barrier function and increase its water-holding capacity in both humans and guinea pigs.
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