Objective: To evaluate the composite external fixation in the treatment of children with fracture of lower extremity metaphysis. Methods: A retrospective analysis was conducted of the 42 children with fracture of lower extremity metaphysis who had been admitted to Zhengda Shaoyang Orthopaedic Hospital between September 2016 and September 2018. They were 24 boys and 18 girls, aged from 3 to 14 years (mean, 8.3 years). Open injury occurred in 10 cases, with type Ⅰ in 2, type Ⅱ in 7 and type Ⅲ in one according to the Gustilo-Anderson classification, and closed injury in the other 32 ones. The fracture happened at distal femur in 12, at proximal tibia in 9 and at distal tibia in 21 cases. All the patients were fixated with composite external brackets. Fracture healing, functional recovery of the knee and ankle joints, and complications were recorded. Results: All the 42 patients were followed up for 12 to 18 months (mean, 15.8 months). All fractures healed well by the first intention with no malunion or no alignment change on the full length X-ray films of both lower limbs. Irritant growth within 1.5 cm was observed in 2 cases. No loosening occurred in the external fixation which was removed 3 to 5 months after surgery (mean, 3.8 months). Functional recovery of the knee and ankle joints was good at the last follow-up. For the patients with distal femoral metaphysis fracture, the knee function by the Merchan scoring was excellent in 3 cases, good in 7 cases, fair in one and poor in one; for the patients with proximal tibial metaphysis fracture, the knee function by the Merchan scoring was excellent in 3, good in 4 and fair in 2 cases; for the patients with distal tibial metaphysis fracture, the ankle function by the Kofoed scoring was excellent in 11, good in 7 and fair in 3 cases, giving an excellent and good rate of 83.3%. Of a total of 228 needle channels in the 42 patients, 58 were infected mildly or moderately, giving an infection rate of 25.4%. All the infections responded to active dressing change. Conclusion The composite external fixation brackets are a good choice for the treatment of children with fracture of lower extremity metaphysis, because they are easy in manipulation and stable in configuration, and can reduce the iatrogenic injury to the epiphyseal plate, spare cross-articular fixation and allow early functional exercise.

Objective To investigate the effects of propofol on intracellular free Ca2+ concentration and nitric oxide synthase (NOS) activity in PC12 cells exposed to bupivacaine. Methods The PC12 cells were provided by Shanghai Cell Biology Research Institute, Chinese Academy of Sciences and cultured in DMEM liquid culture medium. The cultured PC12 cells were seeded in 36 well plates and randomly assigned to one of 4 groups (n=9 wells each): group Ⅰ control (C);group Ⅱ propofol (P);group Ⅲ bupivacaine (B) and group Ⅳ propofol + bupivacaine (PB). In control group D-Hank solution was added. The cells were exposed to propofol 2 mmol/L and bupivacaine 0.09 mmol/L in group P and B respectively. In group PB the cells were incubated with propofol 2 mmol/L and bupivacaine 0.09 mmol/L simultaneously. After being incubated for 6 and 24 h the apoptosis in BC12 cells was assessed by flow cytometry. Apoptotic rate was calculated. NOS activity and intracellular free Ca2+ coneentration in PC12 cells were determined. Results Bupivacaine significantly increased the apoptotic rate of PC12 cells, the intracellular free Ca2+ concentration and NOS activity in PC12 cells in group B as compared with control group. Propofol significantly decreased the toxic effects of bupivacaine on PC12 cells in group PB compared with group B. Conclusion Bupivacaine is toxic to PC12 cells by increasing apoptosis, intracellular Ca+ concentration and NOS activity in the cells. The toxic effects can be prevented to some extent by concomitant administration of propofol.

Objective To investigate the distribution characteristics and risk factors of intracranial atherosclerotic stenosis ischemic stroke. Methods We retrospectively collected 342 consecutive patients with first-ever ischemic stroke. Clinical data was collected including demographics, the presence of risk factors,MRI with MRA and other routine admis?sion laboratory tests. Results Intracranial atherosclerotic stenosis (ICAS) was located most frequently in MCA (47.0%), Extracranial internal carotid artery was the most common affected artery (65.0%) among extracranial atherosclerotic steno? sis (ECAS). MetS (OR=1.586,95%CI:1.232~2.268), ApoB/ApoA1 ratio (OR=1.926,95%CI:1.051~4.288), were as?sociated with ICAS (vs ECAS), whereas hypertension (OR=3.603,95%CI:1.675~12.485), MetS (OR=2.268,95%CI:1.274~6.103), HbA1c (OR=2.015,95%CI:1.182~5.613) and ApoB/ ApoA I ratio (OR=1.948,95%CI:1.157~4.285) were related to ICAS (vs NCAS). Hypertension (OR=2.437,95%CI:1.492~3.505,P=0.005), Hcy (OR=2.437,95%CI:1.492~3.505,P=0.005) and HbA1c (OR=1.769,95%CI:1.034~3.121, P=0.005) were the independent risk factors re?lated to posterior circulation strokes (vs anterior circulation strokes ) in ICAS strokes. Conclusions The occurrence of ICAS may be more frequent than that of ECAS in ischemic stroke. Posterior circulation ICAS strokes seems to be close?ly associated with metabolic derangement.