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Objective To study and to optimize culture conditions of islet-like cells induced in vitro from fetus bone marrow(BM) mesenchymal stem cells(MSCs).Methods BM was obtained from miscarried human fetus.The MSCs between three to eight passages were used to differentiate into islet-like clusters-through three stages of culture supplemented with 2mercaptoethanol,epidermal growth factor(EGF),basic fibroblast growth factor(bFGF),B_(27) and nicotinamide.Results The 2nd stage cells expressed nestin and/or panceatic and duod-enal homeobox 1(PDX-1),and the 3rd stage cells formed islet-like clusters expressing insulin and glucagon together with positive dithizone staining.Specific insulin secretion could be detected(81.3?23.6?u /ml) from differentiated MSCs which have the capacity to respond to different glucose concentrations.Conclusion Fetal bone marrow MSCs can be differentiated into pancreatic islet-like clusters,and 20mmol/L nicotinamide could be the optimal concentration in culture.
RESUMO
The respiratory cilia of normal and abnormal regions in 20 patients with lung cancer or tuberculosis were observed under electron microscope.The results show that the 9?2+2 microtubules arrangement was seen in cross section of the cilium. Ultrastructure of the cilia is about the same as that of other mammalian ceils. However,a very interesting finding was that the ciliary rootlets became greatly hypertrophied.Thus,the structure was easily identified.It appeared as striated muscles. Therefore we propose a new idea that is quite different from Satir's hypothesis about the mechanism of ciliary movement.We think that ciliary rootlets may generate movement rather than fix cilia.Dynein arms and radial spoke may be involved in supporting and fixing for ciliary movement.