Lingual Epithelial Stem Cells and Organoid Culture of Them

As tongue cancer is one of the major malignant cancers in the world, understanding the mechanism of maintenance of lingual epithelial tissue, which is known to be the origin of tongue cancer, is unquestionably important. However, the actual stem cells that are responsible for the long-term maintenance of the lingual epithelium have not been identified. Moreover, a simple and convenient culture method for lingual epithelial stem cells has not yet been established. Recently, we have shown that Bmi1-positive cells, residing at the second or third layer of the epithelial cell layer at the base of the interpapillary pit (IPP), were slow-cycling and could supply keratinized epithelial cells for over one year, indicating that Bmi1-positive cells are long-term lingual epithelial stem cells. In addition, we have developed a novel lingual epithelium organoid culture system using a three-dimensional matrix and growth factors. Here, we discuss current progress in the identification of lingual stem cells and future applications of the lingual culture system for studying the regulatory mechanisms of the lingual epithelium and for regenerative medicine

Scaled-down modelling and microprocessor facilities for the simulation and assessment on HVDC convertor disturbances.

Aimed at the eventual implementation of direct digital control and protection in a.c./d.c. power systems, this thesis describes the design of a thyristor convertor model and an interrupt-driven multiple microprocessor system capable of simulating various faults encountered in real systems, and of monitoring the normal and abnormal convertor operating states in real time. Recent developments of HVDC convertor control and operation are first reviewed, and a fast and reliable method of deriving convertor-valve ON/OFF states is practically implemented in the model and assessed for other applications. A comprehensive set of normal and abnormal convertor waveforms is derived and used as a basis for the software-based fault simulation and fault-data acquisition scheme. The proposed scheme takes full advantage of the versatile and cost-effective general-purpose microprocessor to provide sophisticated convertor operating-state monitoring, fault data recording and immediate display on the inter-connected VDU terminal. In conjunction with the fault simulation scheme, the conditions for fast shut-down of the convertor upon the occurrence of certain disturbances are investigated

Lingual Epithelial Stem Cells and Organoid Culture of Them

As tongue cancer is one of the major malignant cancers in the world, understanding the mechanism of maintenance of lingual epithelial tissue, which is known to be the origin of tongue cancer, is unquestionably important. However, the actual stem cells that are responsible for the long-term maintenance of the lingual epithelium have not been identified. Moreover, a simple and convenient culture method for lingual epithelial stem cells has not yet been established. Recently, we have shown that Bmi1-positive cells, residing at the second or third layer of the epithelial cell layer at the base of the interpapillary pit (IPP), were slow-cycling and could supply keratinized epithelial cells for over one year, indicating that Bmi1-positive cells are long-term lingual epithelial stem cells. In addition, we have developed a novel lingual epithelium organoid culture system using a three-dimensional matrix and growth factors. Here, we discuss current progress in the identification of lingual stem cells and future applications of the lingual culture system for studying the regulatory mechanisms of the lingual epithelium and for regenerative medicine