[Dynamic change and prediction of vegetation cover in Shenzhen, China from 2000 to 2018].

With landsat-series multi-temporal image data, percentage of vegetation cover (PVC) was estimated by pixel dichotomy. The linear regression analysis and center of gravity migration methods were used to explore the characteristics of the spatiotemporal changes of vegetation cover in Shenzhen from 2000 to 2018. The CA-Markov model was combined to predict future land cover in Shenzhen.

Odontogenic potential of mesenchymal cells from hair follicle dermal papilla.

Dental pulp stem cells from teeth can be used for tooth regeneration. Although nondental stem cells derived from bone marrow can differentiate into odontoblast-like cells when recombined with embryonic oral epithelium, these cells can lose their ability to differentiate after an extended number of cell culture passages. There has been limited research to identify stem cells from other tissue sources to regenerate teeth.

[Sequencing and bioinformatical analysis of virulent strain-specific DNA fragments from Streptococcus mutans].

Objective: To search the DNA sequences specific to virulent strain of Streptococcus mutans in the public database and explore new genes or new functions of already known genes from Streptococcus mutans of serotype c and suppose their functions.

Methods: Thirty-one DNA fragments unique to virulent strain of Streptococcus mutans were sequenced. The sequences of these presumptive virulence DNA fragments were subjected to search through software BLASTn and BLASTx in public database, and their putative biological functions were analyzed.

Cell pellets from dental papillae can reexhibit dental morphogenesis and dentinogenesis.

We isolated dental papilla mesenchymal cells (DPMCs) from different rat incisor germs at the late bell stage and incubated them as cell pellets in polypropylene tubes. In vitro pellet culture of DPMCs presented several crucial characteristics of odontoblasts, as indicated by accelerated mineralization, positive immunostaining for dentin sialophosphoprotein and dentin matrix protein 1, and expression of dentin sialophosphoprotein mRNA. The allotransplantation of these pellets into renal capsules was also performed.

[Construction of a virulence-related gene library of Streptococcus mutans by suppression subtractive hybridization].

Objective: To construct a suppression subtractive library of virulence-related genes from c serotype Streptococcus mutans (S. mutans), and lay foundations for screening the virulent genes.

Methods: After being isolated from virulent and avirulent strain of S.

[Tissue engineering of dentin-pulp complex-like structures by human dental mesenchymal cells].

Objective: To establish three-dimensional culture model of human dental mesenchymal cells and bioengineer in vivo with ceramic bovine bone (CBB) and Collagraft as scaffolds.

Methods: Human dental mesenchymal cells induced upon stimulation of bFGF and IGF-1 or TGF-beta(1) were implanted onto CBB and Collagraft containing the same kinds of growth factors respectively. Then cell/scaffold constructs were transplanted into nude mice to establish in vivo culture model of dental mesenchymal cells.

[IRF6 gene mutation analysis in a van Der Woude syndrome family in Henan province].

Purpose: To investigate IRF6 gene mutation in a van Der Woude syndrome (VWS) family in Henan province.

Methods: PCR and DNA sequencing was employed to detect the mutation of IRF6.Secondary construction transformation analysis was performed using PIX-Protein Identification software.

[The positive effect of transforming growth factor beta on ectomesenchymal stem cells of embryonic facial processes differentiating to smooth muscle cells].

Objective: To investigate the effect of transforming growth factor beta (TGF-beta) on ectomesenchymal stem cells differentiating to smooth muscle cells.

Methods: 60 pmol/L TGF-beta was added to the ectomesenchymal stem cells of embryonic facial processes. Immunohistochemistry assay and image analysis were used to value the expression extent of a smooth muscle actin (alpha-SMA) and quantitative RT-PCR was used to value the quantity of alpha-SMA.

[Identification of ectomesenchymal stem cells of human fetal facial processes and spontaneous differentiation to smooth muscle cells].

Objective: To investigate the characteristic and phenotype of ectomesenchymal stem cells of human fetal facial processes and the procedure of spontaneous differentiation to smooth muscle cells.

Methods: The primary ectomesenchymal cells of E 50 human fetal facial processes were isolated by 2.5 g/L trypsin and cultured with DMEM/F 12 with 10(-6) U/L leukemia inhibitor factor(LIF).