[Preliminary investigation on the dynamic change in epidermal stem cells under mechanical stress in vivo].
OBJECTIVE
To observe the distribution of epidermal stem cell (ESC) after soft tissue expansion, and to explore dynamic change in ESC under mechanical stress and kinetic mechanism of skin expansion.


METHODS
Skin samples were collected from patients after expansion of the scalp. They were divided into three groups: A group (scalp harvested 3 cm away from the center of dilator), B group (scalp tissues at the edge of dilator), and control group (scalp without dilatation). The tissue structures were observed with optical microscope with HE staining. The distribution and differentiation characteristics of cell keratin 19 (CK19) positive cells were observed with inverted phase contrast microscope after immunohistochemistry staining.


RESULTS
HE staining showed that the epidermis was thickened and distributed densely with uneven, rugged and increased layers in A, B groups. With immunohistochemistry staining, CK19 positive cells appeared in multilayers in basal membrane, a few of them were in cluster or dispersed , with" hollowing" structure formation. These phenomena were not seen in control group.


CONCLUSIONS
ESC can proliferate with abnormal distribution and "hollowing" structure formation after mechanical dilatation, which may be related to dynamic changes in basal layer cells.
Department of Burns and Plastic Surgery, General Hospital of the Second Artillery PLA, Beijing 100088, PR China.
Hu-Xian
HX
Liu
Bai-Jiang
BJ
Tao
Chi-Yu
CY
Jia
Ding
D
Zeng
Gui-Shui
GS
Li
Ke
K
Sun
Xiao-Chun
XC
Hu
D000293:Adolescent; D000328:Adult; D049109:Cell Proliferation; D022082:Cellular Structures; D004847:Epithelial Cells / Q000166:cytology*; D006801:Humans; D053539:Keratin-19 / Q000378:metabolism; D008297:Male; D013234:Stem Cells / Q000166:cytology*; D013314:Stress, Mechanical; D015626:Tissue Expansion; D055815:Young Adult
D053539:Keratin-19