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.

Objective To determine the intra-and inter-tester reliability of a dynamometer in assessment of knee joint position senses (JPS).Methods Sixteen healthy volunteers (intra-rater N =6,inter-rater N =10) were examined with regard to intra-and inter-tester reliability of knee JPS by using Biodex System 3 dynamometer,measured by passive replication test,with subjects passively returning to the initial positions at 30°,45° and 60° knee flexion.The absolute error (AE) angle was recorded.Both intra-and inter-tester reliability studies involved two testers.Results The intra-tester reliability of the AE were moderate reliable at 30°,45°and 60° knee flexion,and the values of intra-class correlation coefficients (ICC) were 0.728,0.780 and 0.807,respectively.The values of Pearson's correlation coefficients for inter-tester reliability were 0.676,0.610 and 0.705,respectively (P ＜ 0.05).There was no significant difference between the AE values of dominance and non-dominant knees,test and retest,and in the AE values of 30°,45°and 60° knee flexion (P ＞ 0.05).The 95％ confidence upper limits of all subjects' AE values were less than 3°.Conclusion The major findings of this study suggest that the test-retest reliability of the knee JPS were moderate using Biodex System 3 dynamometer,and selecting a target angle of passive replication test can achieve the same purpose in 30° to 60°knee flexion.The clinical significance should be taken into consideration when the AE changes were greater than 3 degrees.

Objective To observe and compare the functional outcomes of early rehabilitation of persons who received primary bilateral or unilateral total knee arthroplasty (TKA).Methods Sixty-eight subjects were divided into a unilateral TKA group (36 cases) and a bilateral TKA group (32cases).All received the same professional rehabilitation program during an average postoperative hospital stay of (15.00 ± 3.71 ) days.At discharge,a visual analogue scale (VAS) was used to rate pain.Active range of motion (AROM) of the involved knee,knee injury and an osteoarthritis outcome score (KOOS) were also assessed.The KOOS and knee society score (KSS) were evaluated at follow-up about 11 months later.Results There was no significant difference between the two groups in any assessment at discharge,nor in the KOOS and KSS-Ⅰ assessments at follow-up.The KOOS of both groups at follow-up had improved significantly compared with that at discharge.The KSS-Ⅱ results in the bilateral group were slightly better than those in the unilateral group at follow-up,and that difference was significant.Conclusions Bilateral TKA patients and unilateral TKA patients had the same clinical outcomes after early postoperative rehabilitation,but the functional outcomes of bilateral TKA patients were better than those of unilateral TKA patients a year later.

Objective:To observe the effects of 8-week interval anaerobic training on the respiratory function, airway inflammatoion and exercise performance in the asthmatic children,and to provide theoretic and practical evidence for special exercise prescription for the asthmatic children.Methods:Forty-six mild asthmatic children were willingly divided into exercise group (n=23)and control group (n=23).The children in exercise group conducted 8 weeks interval anaerobic training while the children in control group maintained intrinsical lifestyle.Before and after experiment,the respiratory function,airway inflammatory reaction and exercise performance were determined by pneumonometer,nitric oxide determinator and cycle ergometer.Results:One patient of each group was lost to follow up.509 persons in exercise group finished the training;11 persons had adverse reaction and the incidence was 2.2%.After experiment,compared with before experiment,the peak expiratory flow (PEF)in exercise group after experiment was increased (P <0.05),the fractional exhaled nitric oxide (FeNO)was decreased (P <0.05), the mean power (MP)and peak power (PP)in 30 s Wingate test were raised (P <0.05);there were no significant differences of all indicators in control group (P >0.05).Compared with control group after experiment,all indexes above (PEF,FeNO,MP and PP)in exercise group existed statistical differences (P <0.05).Conclusion:Interval anaerobic training has safetiveness and effectiveness under proper supervision and could improve the respiratory function,reduce the airway inflammation and enhance the exercise performance in the mild asthmatic children.

Intervertebral disc degeneration is one of the orthopedic common diseases , its complex physiopathological changes are regulated by many factors .The matrix metalloproteinases ( MMPs) and its regulatoryl factors play a very important role , and the factors that affect the role of MMPs in intervertebral disc degeneration interact with each other .So MMPs have gradually become one of the hot spot of intervertebral disc degeneration in recent years .In this paper , we first analyze the factors that cause the degeneration of intervertebral disc .Then we summarize the relationship between the expression of MMPs and the degeneration of intervertebral disc ac -cording to the different function of MMPs members in the family .Finally we state that MMPs can have an effect on the degeneration of intervertebral disc by the regulation of gene polymorphism and the related factors .

Objective To explore the influence of 8-week aerobic exercise in heart rate variability (HRV)in obese adolescents and to provide the evidence for formulating special exercise prescription.Methods Forty male obese adolescents (BMI≥25 kg·m-2 )were randomly divided into exercise group (n=20)and control group (n=20). The subjects in exercise group conducted a 8-week (five times/week,50-60 min)aerobic exercise while those in control group maintained their routine lifestyle. The body composition, hemodynamic parameters including heart rate(HR)and blood pressure and HRV parameters including total power (TP),normalized low frequency (LFn), normalized high frequency (HFn)and LFn/HFn ratio were measured before and after experiment.Results There were no significant differences of the indicators of the subjects between two groups before experiment (P>0.05). At the end of experiment,compared before experiment,the fat mass(FM),the percentage of body fat(BF%), the rest HR,SBP and DBP were decreased (P<0.05 or P<0.01);the TP and HFn were increased(P<0.01);the LFn and LFn/HFn ratio were reduced (P<0.01)in exercise group after experiment;but the indexes of the subjects in control group showed no significant changes (P>0.05).Compared control group,the FM,the BF%, the rest HR,SBP,DBP,LFn and LFn/HFn ratio were decreased while the TP and HFn were increased (P<0.01)in exercise group after experiment.Conclusion Aerobic exercise may effectively reduce the sympathetic activity and increase the vagal tone in the obese adolescents.

s:Bone allografts have been successfully used in repairing bone defect caused by tumor, infection or trauma. The mechanism of bone-healing of allografts has been widely studied. The article reviews the factors affecting the bone-healing of allografts.

In the development of radio frequency (RF) coils for better quality of the mini-type permanent magnetic resonance imager for using in the small animal imaging, the solenoid RF coil has a special advantage for permanent magnetic system based on analyses of various types.of RF coils. However, it is not satisfied for imaging if the RF coils are directly used. By theoretical analyses of the magnetic field properties produced from the solenoid coil, the research direction was determined by careful studies to raise further the uniformity of the magnetic field coil, receiving coil sensitivity for signals and signal-to-noise ratio (SNR). The method had certain advantages and avoided some shortcomings of the other different coil types, such as, birdcage coil, saddle shaped coil and phased array coil by using the alloy materials (from our own patent). The RF coils were designed, developed and made for keeled applicable to permanent magnet-type magnetic resonance imager, multi-coil combination-type, single-channel overall RF receiving coil, and applied for a patent. Mounted on three instruments (25 mm aperture, with main magnetic field strength of 0.5 T or 1.5 T, and 50 mm aperture, with main magnetic field strength of 0.48 T), we performed experiments with mice, rats, and nude mice bearing tumors. The experimental results indicated that the RF receiving coil was fully applicable to the permanent magnet-type imaging system.
Animals ; Magnetic Fields ; Magnetic Resonance Imaging ; instrumentation ; Magnets ; Mice ; Mice, Nude ; Phantoms, Imaging ; Radio Waves ; Rats

Objective To investigate the stimulative effects of CollagenⅠon the increased adhesion of rabbit bone marrow stromal cells (BMSCs), cytoskeleton actin organization and intracellular free Ca~(2+) concentration. Methods The third generation BMSCs isolated from mature rabbits were cultured at different initial concentrations on cover-slice coated by collagenⅠin RPMI1640 containing 10% fetal calf serum, and cultured on the same kind of cover-slice untreated with collagenⅠas control. The cells adhesive behavior at different times was assessed. Cellular actin organization was described as either typeⅠor typeⅡcells. In general, typeⅠcells are round and represent a preliminary stage of actin assembly, while typeⅡcells are elongated with organized actin fiber network. At the same time intracellular free Ca~(2+) concentration was measured by using calcium fluorescent probe Fluo-3/AM and laser confocal microscope. Results We found more typeⅡcells in BMSCs cultured with collagen typeⅠsix hours after culture than in the control group. At 12 hours 89% of the BMSCs were typeⅡcells, while only 55% were typeⅡcells in the control group. This indicated active cellular actin organization after being modified by collagen typeⅠ. We also found that the BMSCs cultured with collagen typeⅠincreased intracellular free Ca~(2+) concentration in monolayer culture. Conclusions CollagenⅠis effective in promoting the cellular adhesion, which suggests that a kind of internal relationship or cross-talk may exist between cellular actin organization, intracellular free Ca~(2+) concentration and cell adhesion. Further study, however, is needed.

AIM:To investigate the changes of brain-derived neruotrophic factor(BDNF),tyrosine kinase B(TrkB) in rat cortex and hippocampus with chronic immobilization stress and the influence of three Chinese formulas(Xiaoyaosan,Sijunzitang,Jinkuishenqiwan) on them.METHODS:Chronic immobilization stress method(180 min daily,repeated 7 days or 21 days) was taken,and the changes of BDNF,TrkB in rat forehead cortex and hippocampus CA1 were measured by immunohistochemistry integrated image analysis.RESULTS:The contents of BDNF in rat forehead cortex and hippocampus CA1 were obviously lower in the model group of 7 days and 21 days than those in the normal control group(P