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.

As one of the most catastrophic complications, prosthetic joint infection remains one of the most stubborn medical problems.However, the biomarkers and laboratory tests commonly used often exhibit either a low sensitivity or a low specificity, which makes it still difficult to diagnose.Therefore, we summarize a number of recent new developments home and abroad, and overview from the aspects of serological markers, synovial fluid markers, radionuclide imaging methods, preoperative periprosthetic tissue biopsy, in-traoperative periprosthetic tissue culture, histological analysis of periprosthetic tissue and new molecular technology.

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.

Bone loss is often presented in the revision of total hip arthroplasty.The selection of appropriate materials to repair bone deficiency in the revision of total hip arthroplasty requires an understanding of the special bioactivity of the materials.The materials provide the bioactivity of osteogenesis,osteoinduction,osteoconduction and mechanical support.The article give a review of the bioactivity and future applications of the materials in repairing bone deficiency in the revision of total hip arthroplasty.

Leptin may indirectly suppress bone formation via a central nervous relay and may stimulate bone formation via direct peripheral effect. Leptin' s antiosteogenic function is mediated through the sympathetic nervous system and does not involve pathways with melanocortin and cocaime-amphetamine-regu-lated transcript, which are critical for leptin' s anorexigenic action. Leptin' s actions to modulate bone formation through sympathetic nervous system could suggest new therapeutic approaches for diseases such as osteoporosis. The progress of the relationship between leptin and sympathetic nervous system and bone formation is reviewed.

Osteogenic protein-1(OP-1),also referred to as bone morphogenetic protein-7(BMP-7),has the effective osteoinduction.In reconstructive surgery of the hip,OP-1 could induce greater and earlier new bone formation,accelerate the incorporation of the graft and host-bone,and enfance the fixation of the plant.The characteristics in the molecular biology and it's application in reconstructive surgery of the hip was reviewed.

Damaged articular cartilage has a limited intrinsic capacity to heal itself,especially in adults,It represents a clinical challenge.Novel gene therapy can introduce particular beneficial gene into the seeded sells and express growth factors or other therapy proteins at the repair site.Gene therapy focuses on selecting proper gene,target cells and the transferring systems. The tissue engineering cartilage with gene-modified seeding cells and transferring objective gene to target sells locally present new therapeutic regimens for repairing defects in articular cartilage.

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.

Cartilage lesions resulting from acute or chronic injury are one of the major factors leading to joint disease and disability ,and eventually osteoarthritis. It is well known that articular cartilage in adults has a limited ability for self-repair,and represent a clinical management challenge. Numerous methods have been devised to augment its natural healing response. The most appropriate treatment option for an individual patient should be based on the pathologic characteristics of the lesion and the patient's symptoms, age and expectations. This review presents the current articular cartilage management and the direction in future therapeutic regimens.

Presently,studies of onset,development and tumor drug resistance of osteosarcoma were few.Further studies on tumor animal models can provide a promising basis for treating osteosarcoma.Commonly used animal models of osteosarcoma include mouse,rat,rabbit and dog.Organs of rats are similar to human,so does genotype.Dogs can spontaneously develop osteosarcoma,which is similar to human,and are frequently used as spontaneous tumor models.However,there are some differences in biological features,pathogenic mechanism and histology.With the development of studying,there will be more and more new animal models in accordance with human osteosarcoma characteristics.The present study served to review methods of establishing models,characteristics and detailed application of animal models of osteosarcoma.