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Biomedical subjects

Zhen Tan

Publications and source records attributed to Zhen Tan.

8 recordsLinked to original sources
PubMed2006

[Influences of orthodontic tooth movement on estrous cycle and estrogen in rats].

OBJECTIVE: To explore the influences of orthodontic tooth movement on estrous cycle and estrogen in female rats. METHODS: Two hundred female rats were divided into control group, one-time activation group, four-time activation group and sham-operated group. Each group was divided again into 4 sub-groups according to the different stage of the estrous cycle. The force-loading groups received repeated intermittent force. Serum estrogen was measured and the change of estrous cycle was recorded. RESULTS: There were significant variations in the estrogen level among the groups which received mechanical force during the same stage of the estrous cycle (P < 0.01) and among the subgroups within each group (P < 0.05). These experimental treatments affected the estrous cycle of the rats in the groups received force in metestrus and diestrus. CONCLUSIONS: Estrus of rats was the appropriate time for the orthodontic force.

Animals↗
PubMed2006

[A clinical study of immediate dental implant and immediate restoration].

OBJECTIVE: To evaluate the clinical results of immediate implant and immediate restoration and to discuss the applying principles of these techniques. METHODS: Fourteen cases underwent immediate implant surgery for 37 dental implants immediately after the teeth or roots were extracted. Among them, 6 cases (14 implants) received immediate restoration after implant placement. The second stage operation and final restoration were performed 4 months on average postoperatively, and the mean follow-up time was 22 months. RESULTS: Two implants from 1 case were lost at 3 weeks after immediate implant and immediate restoration. The rest cases achieved good clinical results. Accumulative 4-year survival rate was 94.6%. CONCLUSIONS: The result of immediate implant and immediate restoration is predictable if the cases are properly selected.

Adolescent↗
PubMed2005

[Influence of basic fibroblast growth factors on the migration, proiferation of osteoblasts and periodontal ligament fibroblasts].

OBJECTIVE: In order to determine the influence of bFGF on the biological characteristics of osteoblasts and periodontal ligament cells, the author investigate the influence of bFGF on the migration, proliferation of osteoblasts and periodontal ligament fibroblasts between osteoblasts and fibroblasts. METHODS: The forth generation of osteoblasts and periodontal ligament fibroblast were obtained and the wounding model in vitro of them was founded. The cells were cultured in mediums with or without bFGF. Their migration and proliferation were observed and measured. RESULTS: Osteoblasts migrated faster than fibroblasts in common culture medium without bFGF and the periodontal ligament fibroblasts in culture medium with bFGF had higher migration rate than other groups. bFGF promoted the proliferation of both two kinds of cells. CONCLUSION: bFGF could accelerate periodontal fibroblasts' proliferation and migration.

Cell Proliferation↗
PubMed2005

[Study on the relationship between 22q11 microdeletion and congenital heart disease].

To investigate if microdeletion of chromosome 22q11 is an epidemiologically important cause of congenital heart disease (CHD), we studied 25 cases with CHD phenotypes. Venous blood samples were tested by fluorescence in situ hybridization (FISH) for microdeletion of 22q11. Among 23 cases with simple CHD, 19 were shown not to have microdeletion of 22q11 and the other 4 cases were shown to have 22q11 microdeletion. Microdeletion of 22q11 was found in 2 cases with Tetralogy of Fallot (TOF) accompanied by multiple malformations. The results suggested that microdeletion of 22q11 was associated with CHD.

Adolescent↗
PubMed2005

[Influences of applying force during the different stages of estrous cycle on orthodontic tooth movement of rats].

OBJECTIVE: To explore the effects of applying force during the different stages of estrous cycle on orthodontic tooth movement of rats, so as to offer an experimental princinple for women's orthodontic treatment. METHODS: 80 female 3-month-old Wistar rats, which had a stable and five-day estrous cycle, were used. They were randomly divided into control groups and loading-force groups. Each group was divided again into 4 sub-groups according to the different stages of the estrous cycle. The loading-force groups received repeated intermittent orthodontic force for four times seperately during the same stage of the estrous cycle. The distance between upper incisor and the first molar on the left was measured. The data were analyzed by One-way ANOVA, S-N-K. RESULTS: There were significant variations in the amount of tooth movement among the groups which received the mechanical force during the different stages of the estrous cycle (P <0.01). There were significant variations in the amount of tooth movement between the groups received force during pre-estrus and estrus (P <0.05). There were not significant variations between the groups received force during metestrus and diestrus (P > 0.05). The largest amount of tooth movement was in estrus group and smallest in pre-estrus one. CONCLUSION: The effect of tooth movement depended on which stage of estrous cycle was chosen to be the time of applying orthodontic force.

Analysis of Variance↗
PubMed2004

[Interaction between osteoblasts and fibroblasts derived from same individual].

OBJECTIVE: In order to determine the effect of factors pertaining to the development and metabolism of periodontal ligament, the author investigated the interaction between osteoblasts and fibroblasts. METHODS: The cell co-culture model was established by cell culture inserts. The expression difference of protein related to mineralization (ALP, Type I collagen) between these two kinds of cells cultured individually and co-cultured were evaluated. RESULTS: Co-culture changed the ALPase activity of the two kinds of cells greatly .The ALP expression of osteoblasts decreased, but the ALP expression of periodontal ligament fibroblasts increased. The Col-I expression of these two kinds of cells did not change significantly when they were co-cultured. CONCLUSION: Periodontal ligament fibroblast could restrain the osteogenesis function of osteoblast, while osteoblast could induce the differentiation of fibroblast when both of them existed in periodontal tissue.

Alkaline Phosphatase↗
PubMed2002

[A study on the correlation between facial growth pattern and posterior-anterior ratio].

OBJECTIVE: This study aimed at finding sensitive indicators in diagnosing facial growth pattern by studying the relationship between the indicators which can reflect facial growth pattern according to the previous studies and posterior-anterior ratio. METHODS: The cephalometric radiographs of 61 teenage children were measured, the posterior-anterior ratio and the other 12 indicators including Y-axis angle, facial axis angle, cranial basal angle, and the four angles (The sagittal horizontal planes were analyzed using statistic methods. RESULTS: The MP-SN angle was significantly coincided with the posterior-anterior ratio and Pearson coefficient is -0.922, and little correlation was found between the angles of four sagital horizontal planes and the posterior-anterior ratio. The positive correlation was found between the length of mandibular ramus and posterior-anterior ratio. CONCLUSION: The sensitive indicators for confirming facial growth pattern are the posterior-anterior ratio and the MP-SN angle.

Adolescent↗