Most medical postgraduates desire to develop their research mentality and experiment skills and become capable medical students with potentialities and innovation consciousness.Medical postgraduates can be classified into academic, general, and clinical types based on their needs, education background, experiences and personal abilities, while their supervisors fall into high-, medium-, and low-expectation types according to their research abilities and demands.Cross-pairing analysis shows that a high-level cooperation can be achieved when the type of a postgraduate matches that of his supervisor, otherwise a low-level cooperation may result.Therefore, it is essential to optimize the two-way choice system between postgraduates and supervisors, establish a moral code for supervisors and academic standards for postgraduates, and further enhance their interaction.A new relationship should be formed between medical postgraduates and supervisors, which is postgraduate-centered, emphatic on conversation, discussion, equality, and mutual trust and respect, and capable of promoting the harmonious development of academic activities.

BACKGROUND:No ideal drugs can be used in the prevention and treatment of aseptic loosening of artificial joints. Some researchs showed that erythromycin has strong inhibitory effects on periprosthetic osteolysis. Its antibacterial activity, however, limits its application in artificial joint loosening prevention. LY267108 is a new type of erythromycin derivatives, eliminates the antibacterial activities, and retains the anti-inflammatory activity.
OBJECTIVE:To evaluate inhibitory effect of LY267108 on nuclear factor kappa B during osteoclast activation.
METHODS:RANKL and macrophage colony-stimulating factor were added to RAW264.7 cellline of a mouse model induced by osteoclasts. Simultaneously, different concentrations of alendronate sodium, erythromycin and LY267108 were cocultured for 48 hours. The activity of nuclear factor kappa B and content of intracytoplasmic inhibitory subunit of nuclear factor kappa B alpha were measured by electrophoretic mobility shift assay and western blot assay.
RESULTS AND CONCLUSION:LY267108 has a strong inhibitory effect on nuclear factor kappa B. 10 mg/L LY267108, 25 mg/L erythromycin and 10 mg/L alendronate sodium had similar inhibitory effects on nuclear factor kappa B, which was obviously stronger than 10 mg/L erythromycin. However, 25 mg/L LY267108 had strongest inhibitory effects. No significant difference in intracytoplasmic inhibitory subunit of nuclear factor kappa B alpha levels was detected among 10 mg/L LY267108, 25 mg/L erythromycin and 10 mg/L alendronate sodium groups, but was stil apparently higher than 10 mg/L erythromycin group. Levels of intracytoplasmic inhibitory subunit of nuclear factor kappa B alpha were highest in the 25 mg/L LY267108 group. Results indicated that LY267108 in the process of osteoclast activation had stronger inhibitory effects on nuclear factor kappa B compared with erythromycin, and its safety was higher than alendronate sodium. Simultaneously, LY267108 did not have antimicrobial activity, and became a potential ideal drug for prevention and treatment of aseptic loosening of artificial joints. However, the inhibitory effects of LY267108 on the degradation of inhibitory subunit of nuclear factor kappa B alpha would be a mechanism of inhibiting the activation of nuclear factor kappa B.

The osteoclast is a hematopoietic cell derived from CFU GM, which is regulated by systemic hormones, soluble factors in the phase of differentiation, fusion and proliferation. The major singnaling pathways involved in osteoclastic bone resorption and formation in response to cytokine and hormones include cAMP and R PTK. The advances in our understanding of the osteoclast make it possible for us to comprehend the development and the treatment of the bone metabolic diseases.

Various kinds of scaffold materials are studied and used in cartilage tissue engineering, but none are ideal for the needs of tissue engineering. Mixing different materials together to form a better composite scaffold may brighten the prospect. The present review summarizes the studies of composite materials in cartilage tissue engineering.

Joint prosthesis is one of the most successful procedures in orthopaedic surgery and has considerably improved the quality of life for patients affected by terminal joint disease. However,a number of joint prosthesis ultimately failed because of aseptic loosening. There have been major advances in the understanding of aseptic loosening. The RANKL-RANK-OPG-NF-?B system has been shown to play a fundamental role in aseptic loosening. We review how the RANKL-RANK-OPG-NF-?B system regulates aseptic loosening and aseptic loosening drug intervention.

Adipose-derived stem cells(ADSC) can be easily obtained in large quantities and with minimal discomfort.As seed-cells,ADSCs may be well suited to tissue engineering and regenerative medical applications.This article presents an overview of the isolation,expansion,characterization,differentiation and application prospects of ADSCs,as well as the existing challenges in their studies,in an attempt to promote their clinical applications.

The scaffold for cartilage tissue engineering should have special physical and biochemical properties,such as excellent biocompatibility,proper biodegradability,controlled porosity,adequate pore size,etc.With the development of cartilage tissue engineering,how to achieve ideal scaffolds is becoming a hot spot in this field.This review outlines the advances in the studies of scaffolds in cartilage tissue engineering.

The hallmark of osteoarthnitis(OA) is the loss of articular cartilage caused by an imbalance between cartilage synthesis and degredation over a variable period of time.IL-1 plays an important role in the course.The IL-1receptor antagonist(IL-Ra) specific against IL-1 is becoming a pivot of wide attention.The article offers a review of the relationship between the IL-1Ra and OA.

Tissue engineering has been a newly developed discipline which represents the new direction of biological medicine engineering.With evergrowing researches on the reparation of bone defect by tissue engineering,great success has been achieved in this field.The three important elements of bone tissue engineering are seed cells,cytokines and cellular biological scaffolds.Bioceramic is an important part of bioactive frame applied widely in tissue engineering.This paper presents a review of the application of bioceramic in the reparation of bone defect,which aims at promoting a systematic knowledge of the application of bioceramic in tissue engineering.

The bone morphogenetic protein(BMP),as a member of the transforming growth factor beta(TGF-?) family,plays a pivotal role in the formation,induction,maintenance and repair of the bone.The expression level of BMPs has a direct influence on the differentiation of mesenchymal osteoprogenitors and the regulation of osteoblastic features.Among BMPs,BMP-2 is the most widely studied and has the strongest activity in inducing bone formation.This article reviews the current advances in researches on BMP-2 for bone repair.