The differentiation of cells composing mature human hairs produces layers with different corneous characteristics that would tend to flake away one from another,as in the corneous layer of the epidermis,without anchor...The differentiation of cells composing mature human hairs produces layers with different corneous characteristics that would tend to flake away one from another,as in the corneous layer of the epidermis,without anchoring junctions.It is likely that cell junctions established in the forming cells of the hair bulb are not completely degraded like in the corneous layer of the epidermis but instead remain in the hair shaft to bind mature cuticle,cortex,and medulla cells into a compact hair shaft.During cell differentiation in hairs,cell junctions seem to disappear,and little is known about the fate of junctional proteins present in the mature human hair shaft.The present ultrastructural immunogold study has detected some marker proteins of adhesion junction(cadherin and beta-catenin)and tight junctions(occludin and cingulin)that are still present in cornified hairs where numerous isopeptide bonds are detected,especially in the medulla.This qualitative ultrastructural study indicates that aside from the cell membrane complex,a long corneo-desmosome bonding cortex and cuticle cells,also sparse adherens and tight junction remnants are present.It is suggested that the cornification of these junctions with the incorporation of their proteins within the mature corneous material of the hair shaft likely contributes to maintaining the integrity of the mature hair.This information will also allow us to evaluate the effects of different chemical components present in hair formulations and stains on these junctional proteins and the consequent integrity of the hair shaft.展开更多
Hairdressers are exposed to numerous skin-damaging factors, such as wet work, skin irritants, and thermal changes. Skin protection is a very important factor for the prevention of occupational skin disorders. Therefor...Hairdressers are exposed to numerous skin-damaging factors, such as wet work, skin irritants, and thermal changes. Skin protection is a very important factor for the prevention of occupational skin disorders. Therefore, we evaluated a hand cream that was specially formulated for highly stressed skin with regard to its capability to reduce dry, rough, and scaly skin. The objective of this study was to conduct a controlled use test of a barrier repair cream containing pseudo-ceramide and demonstrate its efficacy for hairdressers with dry, sensitive hands and/or occupational skin disorders. A total of 30 hairdressers (29 females and 1 male, aged 20 - 67) participated in the study. All subjects suffered from dry hands. Subjects applied the test cream on their hands for 28 days (four weeks). For each subject, the skin surface topography of the hands was measured by the Surface Evaluation of Living Skin (SELS) system at day 14 (week 2) and day 28 (week 4). Dryness, scaling, cracking, redness, and itchiness were evaluated and graded by experts at week 2 and week 4, and then compared to baselines. All 30 subjects completed the study. A comparison of the changes from baseline to endpoint revealed a statistically significant reduction in skin roughness, scaling, and volume measured according to SELS. These data were confirmed by photographic documentation. The results were further supported by the expert evaluation. For the symptoms dryness and scaling, improvement could be observed in almost all regions of the hands. In addition, according to subjective assessments of overall hand skin condition and the hand cream, subjects reported clear improvement over time (p value below 0.001) and good efficacy of the product. In this study, the test hand cream showed excellent skin compatibility. Therefore, the hand cream may be effective for hairdressers with dry, sensitive hands and/or occupational skin disorders.展开更多
文摘The differentiation of cells composing mature human hairs produces layers with different corneous characteristics that would tend to flake away one from another,as in the corneous layer of the epidermis,without anchoring junctions.It is likely that cell junctions established in the forming cells of the hair bulb are not completely degraded like in the corneous layer of the epidermis but instead remain in the hair shaft to bind mature cuticle,cortex,and medulla cells into a compact hair shaft.During cell differentiation in hairs,cell junctions seem to disappear,and little is known about the fate of junctional proteins present in the mature human hair shaft.The present ultrastructural immunogold study has detected some marker proteins of adhesion junction(cadherin and beta-catenin)and tight junctions(occludin and cingulin)that are still present in cornified hairs where numerous isopeptide bonds are detected,especially in the medulla.This qualitative ultrastructural study indicates that aside from the cell membrane complex,a long corneo-desmosome bonding cortex and cuticle cells,also sparse adherens and tight junction remnants are present.It is suggested that the cornification of these junctions with the incorporation of their proteins within the mature corneous material of the hair shaft likely contributes to maintaining the integrity of the mature hair.This information will also allow us to evaluate the effects of different chemical components present in hair formulations and stains on these junctional proteins and the consequent integrity of the hair shaft.
文摘Hairdressers are exposed to numerous skin-damaging factors, such as wet work, skin irritants, and thermal changes. Skin protection is a very important factor for the prevention of occupational skin disorders. Therefore, we evaluated a hand cream that was specially formulated for highly stressed skin with regard to its capability to reduce dry, rough, and scaly skin. The objective of this study was to conduct a controlled use test of a barrier repair cream containing pseudo-ceramide and demonstrate its efficacy for hairdressers with dry, sensitive hands and/or occupational skin disorders. A total of 30 hairdressers (29 females and 1 male, aged 20 - 67) participated in the study. All subjects suffered from dry hands. Subjects applied the test cream on their hands for 28 days (four weeks). For each subject, the skin surface topography of the hands was measured by the Surface Evaluation of Living Skin (SELS) system at day 14 (week 2) and day 28 (week 4). Dryness, scaling, cracking, redness, and itchiness were evaluated and graded by experts at week 2 and week 4, and then compared to baselines. All 30 subjects completed the study. A comparison of the changes from baseline to endpoint revealed a statistically significant reduction in skin roughness, scaling, and volume measured according to SELS. These data were confirmed by photographic documentation. The results were further supported by the expert evaluation. For the symptoms dryness and scaling, improvement could be observed in almost all regions of the hands. In addition, according to subjective assessments of overall hand skin condition and the hand cream, subjects reported clear improvement over time (p value below 0.001) and good efficacy of the product. In this study, the test hand cream showed excellent skin compatibility. Therefore, the hand cream may be effective for hairdressers with dry, sensitive hands and/or occupational skin disorders.
