Matrix metallopmteinase 9(MMP-9) is one kind of matrix metalloproteinases and plays a role in the process of breast cancer metastasis. It can not only degrade the basement membrane and the extracellular matrix around tumor tissue but also promote angiogenesis, even create conditions for the growth of tumors, local invasion and distant metastasis. Current study shows that the over-expression of MMP-9 can significantly speed up the breast lymph node metastasis and the relevant research will provide guidance for clinical treatment and prognosis of breast cancer.

Objective To study the main mechanotransduction area and to estimate the overall shear deformation of rat osteoblasts in shear stress loading experiment based on data acquired from the in vitro rat osteoblast experimental, and to study the effects of four-point bending medium flow generated shear stress on cells. Methods Viscoelastic mechanics theory was used in the calculation process, the standard viscoelastic model was adopted for cells, and shear force on the cellular surface was simplified to be uniform. Results The cellular deformation caused by shear force was about one-tenth of that from tensile loading experiment which induced equivalent biological response. Conclusion In terms of mechanical stimulus induced biological responds, the mechanical transduction caused by cellular deformation in shear stress loading experiment is negligible, and the main transduction area is in the cellular membranes experiencing shear stress.

Induced pluripotent stem(iPS)-cell technology is a great breakthrough in stem cell research field in recent years, it is not only injecting new vitality for the research of reprogramming of somatic cell, but also bringing a new dawn to the study of mechanism of disease and development of regenerative medicine. As key issues of iPS-cell technology, the study of iPS cell induction system has progressed in the composition of transcription factor, gene delivery, as well as induction efficiency. In this article, research advance of iPS cell induction system in recent years is reviewed and the prospect is discussed as well.

Spinal cord injury(SCI) is a serious nervous system trauma,which may consequently lead to various degrees of paralysis and toilet obstacles,and its disability and the high cost heavily burdened the families and community.Therefore,the research on spinal cord tissue regeneration and the repair after injury has important practical significance.A large number of experimental studies have shown that neurotrophic factor plays an important role in the nerve tissue repair process.This article reviews new research progress about the effects of neurotrophic factor in this field.

The development of tissue engineering has provided new methods for organ replacement and disease treatment.The research of seed cells includes cell selection,culture,transplantation,tracing and so on.The tracing technique of seed cells involves molecular biology,molecular immunology,molecular imaging and many other subjects,making it difficult to select a label for seed cells.This review summarizes the recent research progress in the tracing technique of seed cells.

Objective Alzheimer's disease(AD) is a common and devastating disease and there is no readily available biomarker to aid diagnosis or to monitor disease progression. This study is to further understand the pathogenesis of Alzheimer's disease and seek new biomarkers for AD. Methods AD rats made by Aβ1-40 were assessed using the Morris water maze method. Sera of two groups were collected and albumin, IgG and sodium chloride were removed from the serum before concentration. Two-dimensional electrophoresis(2-DE) was performed on serum protein. Altered proteins were identified by matrix assisted laser desorption/ionization time of flight mass spectrometry(MALDI-TOF-MS). Results Compared with untreated samples, 10 altered proteins were found through 2-DE and all of them were down-regulated of which 2 were identified by MALDI-TOF-MS to be plasma retinol-binding protein precursor and complement component 4, gene 2 (C4b). Conclusion C4b may be the biomarker of AD and it may be helpful to understand the pathogenesis of AD.

Based on detailed analysis of the status of and problems in the use and management of implantable medical devices and equipment in clinical departments of hospital, we propose some clinically operable solving strategies and methods. It is important to further regulate the use and management of implantable medical devices for timely and safe use the devices in clinical departments.

Objective To assess the feasibility of using biodegradable poly (lactic-co-glycolic acid) (PLGA) scaffold with controlled release of rhBMP-2 and its effect on the osteogenic activity of MSCs in vitro. Methods The PLGA scaffolds with rhBMP-2 sustained release system were made by combination of porogen-leaching and freeze-drying. The drug release kinetics was measured by enzyme-linked immunosorbent assay (ELISA) in vitro. MSCs were isolated from the bone marrow of human and cultured for 3 passages. Then, MSCs were seeded onto PLGA scaffolds. PLGA scaffolds without rhBMP-2 were used as experimental controls . Scanning electron microscopy(SEM) was used to observe the morphology of MSCs. The cell proliferation was determined by MTT assay. Results The rhBMP-2 was encapsulated into PLGA scaffolds and it was found to be continuously released from the scaffolds. The scaffolds have evident enhancing effect on ectopia osteogenesis. Conclusion PLGA scaffold containing rhBMP-2 is a new promising tissue engineering scaffold.

The ever increasing use of the Single-use medical devices(SUD) in clinic has brought safety and convenience to people, while the management of SUD waste also put pressure on the environment. Reprocess and reuse of SUD has become the issue of social concerns. This paper will describe the management manner of FDA for reprocess and reuse of SUD, and then give some suggestion on China's management combining the national conditions of our country.

let-7e is one member of let-7 miRNA family, a class of endogenous noncoding RNA which consists of 22 nucleotides. The recent miRNA profiles investigation and analysis results showed that let-7e could be involved in embryonic stem cells differentiation, tumorigenesis in cancer, temporal lobe epilepsy and sleep loss, lipopolysaccharide induced inflammation by regulating its target mRNA expression. This paper gives a review of the important biological function of let-7e.