This experiment takes the apute experimental serum sickness (AESS) in rabbits as an animal model to investigate the mechanism of the regulatory effects of Dexamethasone (DX) . The results show. DX doesn't inhibit the production of anti-BSA antibody but induces the tendency to increase the level of antibody in rabbits with DX administration on early days (EL, EH); immune complexes(BSA - anti-BSA IGg, CIC) in the rabbits of EL and EH are significantly increased comparing with the later days (LE, LH) and positive controls. Non-specific esterase stainings and the pathological changes of kidney sections are markedly lessened though the amount of anti - BSA antibody, circulating immune complex (CIC) and superoxides dismutase activity in the rabbits of LE and L H are the same as the positive control. The outcome of protecting kidneys of AESS rabbits from injury by DX administration . probadly results from the effects of that DX inhibits infiltration of monocytes into the glomeruli. The role of oxygen radicals in AESS needs further investigation.

A crucial role in eliciting anti-tumor immunity of costimulatory molecule CD80(B7-1) has been demonstrated by animal experimental studies.In this paper, CD80 expression in human tumor cell lines and EBV-transformed B cell was detected using RT-PCR and FACS methods. The results showed that CD80 expression of Raji and EBV-transformed B cell was positive but that of 3AO,MCF-7,MDA-453,MKN-45, Hela was negative. We have constructed retroviral vector CD80-pLN,transfected package cell PA317, screened high titer rctrovirus supernatant then infected human tumor cell lines and gained CD80 positive tumor cell clones. With pre-and post-CD80-transfected human breast carcinoma cell line MDA-453,the upregulated expression of ICAM-I, HLA class I molecule was observed, but the expression of HLA class II molecule wasn't changed.

Objective:To identify the risk factors for premature proximal femur physeal closure (PPC) in children treated surgically for femoral neck fractures.Methods:Data of 106 children with an open triradiate cartilage who were treated surgically for a femoral neck fracture were retrospectively analyzed. Age, gender, laterality, mechanism of injury, the type of fracture, initial displacement, time to reduction, fixation method, whether the implant crossed the physeal plate, reduction method, reduction quality and development of femoral head avascular necrosis (AVN) were collected. PPC of the proximal femur was assessed through postoperative 6-12 months radiographs.Results:A total of 106 patients with an open triradiate cartilage were followed up, with an average duration of 20.4±13.3 months (range, 6-86 months). The overall rate of PPC following paediatric femoral neck fractures treated surgically was 36.8% (39/106). Among the 39 patients with PPC, 25 were males and 14 were females; the average age at the time of injury was 9.7±3.6 years (range, 3-15 years); 23 patients were involved in left hips and 16 were in right; the mechanisms of injury included motor vehicle accident in 5 fractures, falling injury in 21, sports-related injury in 12 and other causes in 1 fracture; two hips were Delbet type I, and 26 hips and 11 hips were Delbet type II and III, separately; type II and III of initial displacement were involved in 26 and 13 patients, separately; the mean duration from injury to surgery was 3.3±2.8 d (range, 1-14 d); 2 hips were treated with Kirschner wires, 35 hips with screw fixation, and the remaining 2 hips underwent screw and plate fixation; 2 hips had the hardware crossing the proximal femoral growth plate, and the remaining 37 hips didn’t; 15 hips were treated by closed reduction and internal fixation, and the other 24 hips underwent open reduction and internal fixation; anatomical reduction was achieved in 14 patients, acceptable reduction in 24 hips and unacceptable reduction in 1 hip; 24 hips developed AVN at the latest follow-up and the remaining 15 hips didn’t. Statistical analysis indicated that age ( t=3.875, P< 0.001), the severity of initial displacement ( Z=-2.118, P=0.034) and the rate of AVN ( χ2=42.280, P< 0.001) in patients with PPC were significantly higher than those in patients without; Logistic regression analysis confirmed age ( OR=1.288, P=0.011) and AVN ( OR=40.336, P< 0.001) as risk factors for PPC. ROC curve analysis indicated 10 years was the cut off age to significantly increase the rate of PPC. The rate of PPC in patients aged over 10 years (63.6%, 21/33) was significantly higher than that (24.7%, 18/73) in those aged less than 10 years ( χ2=14.848, P< 0.001). Conclusion:Age over 10 years and AVN are risk factors for PPC in children with femoral neck fractures treated surgically.

Compared with the pediatric femoral neck fracture described by the Delbet-Colonna classification, femoral neck fracture with a comminuted posteromedial column is characterized by a more special fracture location. Therefore, it is more difficult to deal with, leading to higher incidences of avascular necrosis of femoral head, coxa vara deformity, and delayed union postoperatively. This paper reviews recent progress in diagnosis and treatment of this specific kind of fracture in the aspects of anatomy and function of the posteromedial column of the femoral neck, and special features, surgical treatment and complication avoidance concerning this fracture, hoping to arouse interest from pediatric surgeons in this specific fracture which has not been described by the Delbet-Colonna classification.