[Psychological impact on the adolescent patients at the beginning of the fixed orthodontic treatment].

OBJECTIVE: To assess whether there is a short negative psychological influence on adolescent patients at the beginning of the fixed orthodontic treatment. METHODS: 150 patients (average 14.8 years old) were selected. All the patients accepted the fixed appliance treatment. They completed a questionnaire regarding anxiety and depression at the first day when they came to the hospital (T1) and 7 days after fixed appliance insertion (T2). 129 effective questionnaires were received. The scales of anxiety and depression of subjects were assessed according to the questionnaires. RESULTS: Comparing the scales of questionnaires before treatment (T1) and 7 days after placement of fixed appliance (T2), there was a significant increase in anxiety and depression scales in female patients, extraction cases and patients who were unwilling to see an orthodontist. CONCLUSION: There is a certain extent of negative psychological influence on adolescent patients during fixed orthodontic treatment. At the first week after the placement of fixed appliance, three kinds of subjects, female patients, extraction cases and patients who were unwilling to see an orthodontist would suffer from anxiety and depression in emotional reflection.

[A study on transfection of green fluorescence protein gene into human adipose stromal cells in vitro].

OBJECTIVE: To make a comparison on the efficiency of two methods for transfecting Green Fluorescence Protein gene into human adipose tissue-derived stromal cells, and to study the biological properties and multipotential differentiation of gene-transfected cells. METHODS: The human subcutaneous adipose tissue was obtained, digested with one volume of collagenase type I, and then cultured with BGJb medium. After subculture and expansion, the human adipose tissue-derived stromal cells infected with Ad-GFP or liposome were observed and analyzed with fluorescence microscopy and flow cytometry to assess transfection efficiency. The growth curve of transfected adipose tissue-derived stromal cells was protracted. The adipose tissue-derived storomal cells were induced to differentiate into osteoblasts, and non-transfected cells were set as control. RESULTS: 42.5% +/- 1.5 of the human adipose tissue-derived stomal cells infected with Ad-GFP were found to express GFP at a level higher than that of the control of liposome (11.40%). Infected adipose tissue-derived stromal cells were noted to form mineralized nodes by the use of Alizarin Red stain. CONCLUSION: The human adipose tissue-derived stromal cells infected with Ad-GFP can express higher level of GFP, and can maintain the ability of proliferation and differentiation as the non-infected human adipose tissue-derived stromal cells do. The infected adipose tissue-derived stromal cells with Ad-GFP can track the change of adipose tissue-derived stromal cells in the study of multipotential differentiation and can serve as cellular vehicles for systemic gene delivery.

[Study on multi-lineage potential of bone marrow mesenchymal stem cells derived from green fluorescent protein transgenic mice].

OBJECTIVE: To study the multi-lineage potential of bone marrow mesenchymal stem cells (MSCs) derived from transgenic mice with green fluorescent protein (GFP) gene in vitro. METHODS: A 6-week-old GFP transgenic mouse was executed by dislocation of cervical vertebra, and the marrow in tibia and thighbone was washed out with asepsis. The limited cell strains of MSCs derived from GFP transgenic mice (GFP-MSCs) were obtained with density gradient centrifugation. The passage 3 GFP-MSCs were induced to differentiate into osteoblast, adippcyte, neuron with solution of calcium induction medium, adipogenic medium and neural induction medium respectively. After being calcium-induced, the activity of alkaline phosphatase on GFP-MSCs was determined by micro-plate reader, and alizarin red staining was performed to test the formation of calcium concentration. The adipo-induced MSCs were detected with oil red O staining. Immunocytochemical staining was performed to detect the expression of NSE on neuron-induced MSCs. RESULTS: The ALP activity of GFP-MSCs heightened gradually along with being calcium-induced, and alizarin red staining showed positive. Oil red O staining of adipo-induced cells and NSE immunocytochemical staining of neuron-induced cells demonstrated positive. CONCLUSION: The limited cell strain of GFP-MSCs possesses multi-lineage potential, which can be used as an efficient tracking facility for studying the mechanism of multi-lineage potential on the MSCs.

[A study on the chondrogenesis of the compound of alginate gelatin and bone marrow stromal cells in vivo].

OBJECTIVE: To investigate the chondrogenisis by alginate gelatin and rats' bone marrow stromal cells (BMSCs) chondrogenicly induced in vitro. METHODS: Thirty-two male adult SD rats were assigned randomly to experimental and control groups. In experimental group, bone marrow was obtained from the right tibias of all the rats. After expanding and culturing 3 passages, induced BMSCs by chondrogenic culture medium for 10 days. Suspended induced cells in alginate gelatin, and injected the complex into the hypodermic tissue of the backs of rats autogenously. In control group only alginate gelatins were injected. The grafts were taken out for examinations 4 and 8 weeks after the operations. RESULTS: Considerable cartilage appeared in experimental group 8 weeks after operations. Regular HE staining and alcian blue staining showed a great deal of cartilage holding chondrocyte masses surrounded by abundant matrix. Alginate gelatin decompounded obviously, and the rest distributed among newly formed cartilage. No cartilage appeared in control group all through. CONCLUSION: BMSCs and alginate gelatin have a beautiful future in cartilage tissue engineering.

[A study on transfecting green fluorescent protein gene to rat bone marrow mesenchymal stem cells].

OBJECTIVE: To study an efficient method to transfect green fluorescent protein gene (GFP) to rat bone marrow mesenchymal stem cells (MSCs) and to determine the biological properties and differentiation potency of transfected MSCs. METHODS: SD rats' bone marrow MSCs were separated and purified in vitro. After subculture and expansion, MSCs infected with Adenoviral vector (Ad-GFP) or transfected with liposome were observed, and their transfection efficiency was assessed with flow cytometry. The MSCs expressing GFP gene were induced to differentiate to osteoblast, and non-transfected MSCs were set as control. RESULTS: Ad-GFP delivered GFP gene with high efficiency to rat MSCs. (41.3 +/- 1.4)% of MSCs infected with Ad-GFP expressed GFP gene, which was much higher than the control (12.5%). Expression of GFP gene of infected MSCs maintained stable from 1 to 6 weeks after infection. Infected MSCs possessed the same alkaline phosphatase activation as non-infected MSCs, and formed mineralized mouldes. CONCLUSIONS: The infected MSCs with Ad-GFP expressed GFP with much higher efficiency than liposome transfection, and maintained the same ability of proliferation and differentiation as non-infected MSCs. Transfection with Ad-GFP is a highly effective method for labeling MSCs.

[Establishment of a culture system of chick embryo for mouse tooth germ development].

OBJECTIVE: To establish a new culture system for mouse tooth germs in chick embryo. METHODS: The mandibular first molar germ fragments of 15 embryonic days' Kunming mouse embryo were implanted into the lateral mesenchyme of 4-5 days' chick embryo wing buds in ove. Eggs were reincubated and implanted tissues were examined by histochemistry. RESULTS: The cultured tooth germ development continued from cap stage to latest bell stage. The ameloblast and the odontoblast all differentiated maturely and secreted matrix. CONCLUSION: 4-5 days' wing buds chick embryo could serve as developing the mouse tooth germs and demonstrate well physiological process of differentiation and morphogenesis.