[The effect of different concentrations of fluoride on the expression of Smad2/3 in ameloblast of rat incisor].

Purpose: To investigate the effect of different concentrations of fluoride on the expression of Smad2/3 which is a specific intracellular signal transduction molecule of TGF-β, and to explore the mechanism of dental fluorosis in rat.

Methods: Forty Wistar rats were randomly divided into 3 groups.HE and immunohistochemistry were used to detect the changes of the ameloblasts and the expression of Smad2/3 in rat incisors.

[Effect of fluoride on the expression of MMP-20/TIMP-2 in ameloblast of rat incisor and the antagonistic effect of melatonin against fluorosis].

Purpose: To study the effect of concentration of fluoride on the expression of matrix metalloproteinase-20(MMP-20) and tissue inhibitors of metalloproteinase-2 (TIMP-2) in the ameloblast of rat incisor,and explore the formation mechanism of dental fluorosis. By comparing the different expression of MMP-20,TIMP-2 between fluoride group and the melatonin group,to decide whether melatonin has antagonitic effect on dental fluorosis.

Methods: Forty Wistar rats were randomly divided into 6 groups.

Transplanted bone marrow stromal cells migrate, differentiate and improve motor function in rats with experimentally induced cerebral stroke.

Bone marrow stromal cells are multipotential cells that can be induced to differentiate into osteoblasts, chondrocytes, myocytes and adipocytes in different microenvironments. Recent studies revealed that bone marrow stromal cells could improve neurological deficits of various damages or diseases of the central nervous system such as Parkinson's disease, brain trauma, spinal cord injury and multiple sclerosis, and promote glia-axonal remodeling in animal brain subjected to an experimentally induced stroke. In the present study, bone marrow stromal cells were intracerebrally transplanted into the cerebrum following a transient middle cerebral artery occlusion.