Tissue engineering has been one of the most challenging and rapidly developing frontier fields of science in the recent 20 years. Being referred to as “a medical revolution of far-reaching significance”, “a new epoch of regenerative medicine”, it signals the coming of a period of reproduction of regenerative tissue and organs. It has drawn intensive attention and support from medical circles and governments all over the world because of its advantages in trauma repair, functional reconstruction, life saving and improving quality of life, as well as its huge social and economic values. Products of tissue engineered skin and cartilage with approval of the American FDA have been available. Hundreds of tissue engineering companies and research centers have been set up both abroad and at home. It is now possible to construct tissue-engineered tissues. Moreover, projects of complex organ construction by means of tissue engineering is being carried out vigorously in the world. Some tissue-engineered tissues have been put into trial use in clinic and resulted in encouraging outcome. All these forecast a bright and promising prospect for tissue engineering. As a new branch of science and technology that involves multiple specialties and fields, however, it is still at its initial stage. Many fundamental scientific problems are to be explored, and many technical difficulties to be overcome. Hope and difficulty coexist; opportunity and challenge stand side by side. We should seize the opportunity and meet the challenge with our creative and strenuous efforts to make tissue engineering benefit human beings as early and much as possible.

With 20 years’ development, tissue engineering has proceeded to a new stage where the focuses of research are quite different from those at the initial stage. Clinical application and industrial development have been the chief concerns for tissue engineering. After brief comments on the current advances and future prospects, this paper suggests that the future tendencies and strategies will be the primary clinical application, industrial development of tissue engineering products, increasing integration of basic research and clinical application and industrial development, construction of bionic and intelligent tissues or organs, and reliability evaluation. This paper also puts forward some strategies.

Bone tissue engineering is the focus of recent research. Its status quo and tendency are discussed from scaffold, cell and tissue reconstruction. Based on this analysis, we want to shorten the distance before it's clinical application and give some reasonable methods.

The research on war injuries in tropical areas is an important subject to be urgently dealt with at present in Chinese military medicine. Military medicine related to hot and humid environment is a significant branch of military environmental medicine. More efforts should be made in the research on care of war injuries as well as on military hygiene and military epidemiology so as to establish an integrated system involving basic and clinical science and art in military environmental medicine in hot and humid areas, which should be considered as an important task in the transition of our military strategy to win a war with improvement in the military medical support capability in a local high technicology conflict in such an area. In this paper, the significance of paying more attention to the research on the care of war injuries in hot and humid areas is emphasized, their features are highlighted, and main problems demanding further research are proposed.

OBJECTIVE: Polylactic acid (PLA) is a biodegradable polymer possessing good biocompatibility and biodegradability, and approved as a biomaterial for in vivo implantation by American Food and Drug Administration (FDA). The role of cytokines in promoting osteogenesis and vascularization for constructing tissue-engineered bones has received increasing attention.But exogenous cytokine has shorter half-life in vivo and can not reach and maintain relatively high local level for bone repair. This article reviews the present researches and analyzes the application prospect of PLA and its derivatives in bone tissue engineering to serve as the carrier for polypeptide and protein medicines with controlled release through its degradation.DATA SOURCES: Related articles published between 1993 and 2004were searched in Medline database with key words of "polylactic acid,bone morphogenetic protein, vascular endothelial growth factor, TGF- beta", limiting the language to English; meanwhile the related medical papers between 1993 and 2004 were also searched in the Chinese Periodical Database, limiting the language to Chinese.STUDY SELECTION: Related researches on PLA and its derivatives for constructing bone tissue-engineering Scaffolds and study of PLA scaffolds carrying cytokines were included with the obsolete literature and repetitive researches eliminated.DATA EXTRACTION: Altogether 96 related literatures on PLA and its derivatives for constructing bone tissue-engineering scaffolds were collected, 23 of which were included in this review.DATA SYNTHESIS: PLA/PLA-polyglycolic acid copolymer is a good biodegradable scaffold for controlled drug release, having the dual functions as scaffolds and sustained-release drug carrier. PLA is the earliest scaffold material in bone and cartilage tissue-engineering, and also the most widely used tissue-engineering material at present. BMP is the most frequently adopted cytokine in bone tissue-engineering, and PLA scaffolds carrying sustained-release BMP is studies most thoroughly, but researches on PLA scaffolds carrying vascular endothelia growth factor has not been conducted.CONCLUSION: Development and application of PLA scaffolds carrying various sustained-release cytokines has become the new interest in bone tissue-engineering researches.

Objective This article aimed to describe an interactive segmenting method for serial anatomical cross-sectional image of Chinese Digital Human(CDH) using commercially available software,Photoshop CS(Adobe;San Jose,CA,Corel KnockOut 2.0 plug-in) and Matlab 7.0(Math Works;Worcester,MA). Methods First,the interesting region was segmented from the image interactively utilizing the Knochout menu of Adobe Photoshop which had a powerful masking function.And then smooth contour was acquired precisely by morphological operation function and edge detection operator(the Sobel method) in Matlab. Results The segmentation and classification of bone,muscle and main vascular nerve were fulfilled successfully and the smooth contour lines were acquired with precise details and accurate localization.Conclusion This local clustering segmenting method might segment and classify the colored image of Chinese Digital Human quickly and precisely.

Objective To observe the effect of transformation of vascularized tissue-engineered bone with vascular bundle graft in vivo. Methods The bone marrow stem cells (BMSCs) obtained from rabbit os ilium were cultured, expanded and induced to form osteocytes, then they were combined with porous ?-tricalcium phosphate (?-TCP) to construct tissue-engineered bone. The tissue-engineered bone was implanted in a segmental defect with critical length of 15mm in rabbit femoral shaft. A bundle containing both artery and vein was inserted in the centre of the tissue-engineered bone with microvascular surgical technique. After an examination with DEXA bone scanner, the specimen was harvested for macroscopic and histological examination after 12 weeks of growth period. Results The site where the implanted vascular bundle inserted into the tissue engineered bone appeared like foramen nutriens, the blood vessels were patent. Abundant blood vessels, which emerged from the deep tissue of the engineered bone, were evident on the surface of specimen. Multicentric ossification area rich in blood vessels could be seen in the tissue-engineered bone histologically. The enchondral ossification in the center of tissue-engineered bone and membranous ossification in the periphery occurred simultaneously. Some materials in the centre of tissue-engineered bone had transformed into marrow cavity like construction. The results of the DEXA demonstrated that the vascularized tissue-engineered bone produced more boney tissue. Conclusions Implantation of blood vessel bundle into tissue-engineered bone may enhance neovascularization of the tissue-engineered bone and accelerate the process of reconstruction subsequently, and it is a promising method of vascularization of tissue-engineered bone.

This article reviews the currently most widely used methods and their features of the non operative and operative treatment for the fractures of long tubular bones. It is widely accepted that each of the two methods is useful in its injury degree and in kind. It is wise to choose the non operative treatment for child fractures, adult fractures easily reduced, and the complementary therapy after surgery. External bone fixation is preferentially selected as for the open long tubular bone fracture with severe injuries to the soft tissues, early freatments of long tubular bone fracture with multiple injuries all over the body and fire arm injury. While it is widely accept that an active operative treatment should be take for the open fractures, multiple fractures, multi plane fractures, intraarticular fractures, and the fractures with vessel or nerve injury, and the biological fixation should be chosen in order not to impair circulartory supply of soft tissues. Arriving at the conclusions that future studies of the treatments for the fractures of long tubular bones will be conducted in meticulously design for therapy, minimally invasive osteosynthesis, satisfactory reduction, stably biological fixation, immediately active motion and results in a good runctional recovery for the limbs.

Objective To study the expression patterns of neuropeptide Y(NPY)and vasoactive intestine peptide(VIP)during the bone development,and its possible relationship with angioge nesis and osteoblast differ-entiation.Methods The bones of low extremity of SD embry o and new -born rats were taken,fixed in formalin and packed by paraffin wax.The developmental stages of bone were determi ned by HE stain The representative specimen were picked out and within t he same layer the sections were taken immunohistochemical stain respective to anti-NPY,VIP,vasoepithelial grow th factor(VEGF)and alkaline phosphatatase(AP).The location and intensity of stain were compared by microscopi c observation.Results During the earliest stage of osteoge nesis,there was no sign of angiogenesis while osteob last began to differentiate and it parallels the intensity of ossificati on activity.At the first ossification center,the l ocation and pattern of NPY expressio n are similar to those of VEGF.Conclusions Due to VIP expression at the earliest stage of osteogenesis,the bone tissue may have the independent nerve control before angiogenesis.The expression similarity of timing and lo cation between NPY and VEGF suggests there is certain relationship between NPY-energetic nerve and angiogenesis.