ABSTRACT
BACKGROUND:Although several prosthetic methods, such as artificial denture and dental implants, are clinical therapies to tooth loss, they are thought to have safety and usage time issues. With the development of biological and biomaterial sciences, recently, tooth tissue engineering has attracted more and more attention. OBJECTIVE:To reflect advances and problems of tissue engineering technologies for promotion of tooth regeneration. METHODS:Using the keywords of“tissue engineering, tooth regeneration”in English and Chinese, PubMed and CNKI databases from 2007 to 2013 were retrieved. A total of 65 literatures addressing tooth regeneration and tissue engineering were col ected, including 25 Chinese articles and 40 English articles. Published early, repetitive, and similar researches were excluded. Final y, 48 articles were included. RESULTS AND CONCLUSION:The combination of stem cells and suitable scaffolds is widely used in tooth regeneration today, and growth factors or bone marrow which can produce promote tooth regeneration are added as wel , which has achieved partial or whole tooth regeneration. But there are apparent deficiencies in studies which focus on mechanisms behind tooth regeneration.
ABSTRACT
Objective To provide anatomical evidence for the repair of wounds of finger distal phalanx,espe-cially for the recovery of feeling. Methods 10 samples of fresh adult hand were dissected under microscope. The course,branches,distribution and external diameter of nerves and blood vessels in finger distal phalanx and morpho-logical relationship between nerves and vessels were measured. Results Proper palmar digital nerves mostly step over digital arteries at section starts of distal finger arterial arcades and go to finger pulps and latero-backs. Their thinks di-vide into 2 branches. Transverse diameters of interior and exterior branches are 0.8 ～ 1.2 mm and 0.9 ～ 1.4 mm re-spectively at liner semilunaris levels. Distributionsof left and right branches are reciprocal chiasmas. Conclusion Finger nerve mostly ramifies to finger pulp,finger tip and finger back at the level of phalangette bottom. Its branches are lower and thinner than concomitant arteries. The suitable anatomy region for anastomosis of nerves and blood ves-sels is the middle1/3 section from the distal interphalangeal joint to the nail during replanation of amputated finger pa-ratelum.
ABSTRACT
BACKGROUND: Peripheral blood stem cells (PBSCs) can be enhanced and differentiates into all kinds of neural cells and produce several kinds of neural growth factors in vitro, and have been used to treat several kinds of neural diseases and they showed satisfactory outcomes. It is now a research focus to optimize the culture conditions to induce the stem cell to differentiate into neural cells. On the other hand, it also becomes a focus of its amplification and differentiation. OBJECTIVE: To make a review on researches on treating brain lesion, genetic defection or degenerating diseases using PBSCs during recent years.METHODS: Researching Pubmed database(1999-01/2009-09), using "peripheral blood stem cell, neural, repair" as research words and these Chinese words in CNKI database(1999-01/2009-09). RESULTS AND CONCLUSION: 221 articles were collected altogether including 41 Chinese articles and 180 English articles. Totally 27 articles were adapted altogether after rejecting published early, repeat and similar articles. PBSCs can be enhanced and differentiates into all kinds of neural cells in vitro, and delivered into central neural system and improve the function of lesion neural area. It is not fully understood the differentiation mechanism of peripheral blood stem cells, but numerous studies have shown that surface marker antigen of peripheral blood stem cells is closely associated with its biological characteristics. There are many studies addressing surface marker of peripheral blood stem cells, but researchers cannot identify a reliable marker that can directly label peripheral blood stem cells. Function of CD34 remains unclear, so the principle of CD34 as a marker of hematopoietic stem cells receives challenge. It is necessary to do further researches on issues on how to enhance survival rate of PBSCs in vivo and the tendency to differentiate into neural cells.
