To investigate the culture method for epidermal stem cell in vitro. Rat skin was peeled from the subcutaneous tissue gently, and cut into small pieces, then incubated for 24h in 0 25%trypsin in a 4℃ shaker. The epidermis was separated from the dermis, and shaken for 10min in 0 25% trypsin at 37℃ to dissociate into single cells. Digestion was terminated by the addition of culture medium +10% serum, and the cells were gently centrifuged and resuspended in the culture medium, which constituted EMEM without calcium, supplemented with 0 05mmol/L CaCl 2 , 9% chelexed FBS, 4ng/ml EGF, 0 5?g/ml gentamicin, and 50% fibroblast conditioned medium (CM ). The CM ( EMEM without calcium, 0 05mmol/L CaCl 2 , 9% chelexed FBS, 0 5?g/ml gentamicin ) was collected from freshly isolated primary neonate fibroblast cultures after 48h, which were passed through a filter with 0 45?m pores, and stored at -20℃ for use. 1?10 6 /ml epidermal cells were incubated for 10～15min at 37℃ on dishes coated with collagen Ⅳ, then the nonadherent cells were rinsed off. The adherent cells were grown to confluency. Cultures were subcultured in a solution of TGG for 5～10min. Once free of the dish, cells were centrifuged, resuspended in fresh medium, and then cultured at 1?10 5 /ml. Cultures were observed for colony formation under a phase contrast microscope, and the structure of the rapidly adherent cells was observed under electron microscopy; the expression of ? 1 integrin and K19 was detected in the rapidly adherent cells and colony cells with SP immunohistochemical methods. The results showed that the cells selected by rapid adherence to collagen type Ⅳ formed large colonies at 7 days, and showed a im mature feature under electron microscopy, manifesting ? 1 integrin and K19 expression. It is suggested that epidermal stem cells could be cultured in vitro .

The development of sweat glands is a very complex biological process, which involves many factors. In this study, the correlation between epidermal growth factor (EGF), matrix metalloproteinases (MMP 2,MMP 7) and development of sweat glands in human embryos was explored. Furthermore, the mechanism(s) underlying the induction of epidermal stem cells into sweat gland cells was elucidated. Skin biospies of human embryos obtained from spontaneous abortions at different gestational ages from 11 to 31 weeks were used. The dynamical expression of EGF, MMP 2, MMP 7 and keratin 7(K7) in developing sweat gland cells or extracellular stroma surrounding the sweat gland cells were examined with S P immunohistochemical methods. The localization of the cellular sources of MMP 2 and MMP 7 was examined with in situ hybridization. The results showed that at 14 20 wk of gestation, a gradual increase of EGF immunoreactivity was observed not only in developing sweat gland buds but also in extracellular stroma surrounding the buds,and the expression intensity peaked at 20～22 wk of gestational age. All mRNA positive buds or cells in developing sweat glands contained corresponding immunoreactive proteins. The immunostaining for K7 appeared in early sweat gland buds at 14～16wk of gestation, and from then on, K7 was concentrated in developing sweat gland cords or cells. It is suggested that the morphogenesis of sweat gland in human fetal skin begins at 14～16wk of gestational age, and essentially completes by 24wk. There is a close relationship among EGF ,extracellular matrix remodeling and morphogenesis of sweat glands, and EGF is one of the inducers in the development and maturity of sweat gland buds or cells.

To investigate the distribution of epidermal stem cells in regenerating wound tissues, and to elucidate the role of epidermal stem cells during wound repair. 80 circular full-thickness wounds were produced on both sides of the back in 20 male Wistar rats labeled 60 days previously with 5-Bromodeoxyuridine (BrdU) (4 wounds in each animal). Then these 80 wounds were randomly divided into 2 groups as follows: group A: with topical treatment of epidermal growth factor (n=40) and group B: no-treatment (n=40). BrdU, ? 1 integrin and keratin19 (K19) were employed to determine the epidermal stem cells with streptavidin-peroxidase (SP)immunohistochemical method, and the speed and quality of epithelialization were determined with routine histological methods with HE staining on the 3rd, 7th, 14th, and 21st day after the wounding. Results showed that the healing rate of wounds was 80% in group A (32/40) and 60% in group B (24/40). No cells with positive immunostaining for BrdU, ? 1 integrin, or K19 were found in the granulation tissue of all wounds in both groups during the healing process. However, a few BrdU, ? 1 integrin and K19 positive cells, bearing no anatomic relation with the epidermal stem cells in the basal layer, were found scattering in the stratum spinosum and stratum granulosum of the epidermis on the wound edges. The results suggested that epidermal stem cells appearing on the wound edges were the main source of re-epithelialization of granulating wounds.

The differentiation of cell is a very important biological process. In this paper, the current understanding and advances in research on dedifferentiation are reviewed. Giving more efforts to study this subject may help us disclose the mechanisms and treatment for some diseases.

Case-Control Studies ; Child, Preschool ; Congenital Hypothyroidism ; DNA ; genetics ; Female ; Humans ; Hypothyroidism ; genetics ; Infant ; Iodine ; metabolism ; Male ; Mutation ; Polymerase Chain Reaction ; Sodium ; metabolism ; Symporters ; genetics

Objective To explore the effect and adverse reaction of priming regimen CAG in treatment of acute myeloid leukemia in elderly.Methods 32 elderly patients with acute myelogenous leukemia were treated with CAG regimen and 25 cases with standard chemotherapy regimen( DA regimen). The effect and adverse reaction were compared between the two groups. Results There was no significant difference of the complete remission rate and effective rate between the two groups. The recovery time of bone marrow and death rate of CAG the regimen group were superior to those of the DA group. Conclusion CAG regimen was effctive and safe for elderly patients with acute myeloid leukemia.

Catheter Ablation ; methods ; Humans ; Hypertension ; surgery ; Renal Artery ; Sympathectomy ; methods

Choristoma ; Humans ; Infant ; Jaw Diseases ; Male ; Palate, Soft

Humans ; Ligands ; Neoplasm Invasiveness ; physiopathology ; Neoplasm Metastasis ; physiopathology ; Neoplasms ; metabolism ; Receptors, CCR7 ; metabolism

Objective To investigated the distribution of epidermal stem cells in rat full-thickness wound tissues during the wound healing process and to elucidate the roles of epidermal stem cells in wound repair in vivo. Methods Eighty circular full-thickness wounds were produced on both sides of the back in 20 male Wistar rats labeled with BrdU 60 days previously (4 wounds in each rat). BrdU, β1 integrin and keratin 19 (K19) were employed to determine the epidermal stem cells with SP immunohistochemical methods, and the epithelialization was determined with routine histological methods of HE staining on the 3rd, 7th, 14th, and 21st days after operation. Results No cells with positive immunostaining for β1 integrin, K19 and BrdU were found in granulation tissue of wound in both groups during the healing process. However, a few scattered β1 integrin and K19 positive cells were found within the stratum spinosum and stratum granulosum of the epidermis on the wound edges on the 3rd day post-injury. And these positive cells gradually became more and more in number, and mostly concentrated on the border of wound edges till the wounds healed. In addition, the number of positive cells for β1 integrin and K19 in the infected wounds was less than that in non-infected wounds. These positive cells for β1 integrin and K19 staining on the wound edge were also positively stained with BrdU in the cellular nuclei. Conclusion The above results indicate that ectopia of epidermal stem cells present a major function during wound epithelialization.