ObjectiveTo evaluate the in vivo biological safety of porous zinc oxide (ZnO)/hydroxyapatite (HA) composite materials.MethodsThe porous ZnO/HA composite materials and porous HA materials were prepared by the spark plasma sintering technology. First, the materials were characterized, including scanning electron microscopy to observe the material structure, in vitro degradation experiments to detect the degradation rate of the materials, and inductively coupled plasma emission spectrometer to detect the concentration of Zn2+ dissolved out of the composite material degradation. Then the two kinds of material extracts were prepared for acute systemic toxicity test. Fifteen male Kunming mice were randomly divided into groups A, B, and C (n=5) and injected intraperitoneally with normal saline, HA extracts, and ZnO/HA extracts, respectively. The body mass of the mice was recorded before injection and at 24, 48, and 72 hours after injection. The liver and kidney tissues were taken at 72 hours for HE staining to evaluate the safety of the composite material. Finally, the biological safety of the material in vivo was evaluated by implantation experiment. The eighteen male New Zealand white rabbits were randomly divided into HA group and ZnO/HA group (n=9); a bilateral radius defect model (1 cm) was established, and the right forelimbs of the two groups were implanted with porous HA materials and porous ZnO/HA composite materials, respectively; the left untreated as a blank control. The general condition of the animals were observed after operation. The rabbit blood was collected at 1 day before operation and at 1 day, 1 week, 4 weeks, and 8 weeks after operation for routine blood test (inflammation-related indicators) and blood biochemistry (liver and kidney function-related indicators). X-ray films were taken at 4, 8, and 12 weeks after operation to observe the repair of bone defects.ResultsMaterial characterization showed that porous ZnO/HA composite materials had interconnected large and small pore structures with a pore size between 50 and 500 μm, which degraded faster than porous HA materials, and continuously and slowly dissolved Zn2+. The acute systemic toxicity test showed that the mice in each group had no abnormal performance after injection, and the body mass increased (P<0.05). HE staining showed that the cells shape and structure of liver and kidney tissue were normal. Animal implantation experiments showed that all rabbits survived until the experiment was completed; routine blood tests showed inflammation in each group (neutrophils, monocytes, and lymphocytes increased) at 1 day after operation, and all returned to normal at 8 weeks (P>0.05); compared with 1 day before operation, the content of inflammatory cells in the HA group increased at 1 day, 1 week, and 4 weeks after operation (P<0.05), and the ZnO/HA group increased at 1 day after operation (P<0.05); blood biochemistry showed that the liver and kidney function indexes were in the normal range; X-ray films showed that the ZnO/HA group had better osseointegration than the HA group at 4 weeks after operation.ConclusionThe porous ZnO/HA composite material has good in vivo biological safety and good bone repair ability, which is a potential bone repair material.
Objective To assess the effectiveness and safety of trazodone versus alprazolam on adults’ generalized anxiety disorder (GAD). Methods Such databases as PubMed (1980 to May 2012), CBM (1990 to May 2012), VIP (1989 to May 2012), CNKI (1990 to May 2012) and WanFang Data (1990 to May 2012) were searched to collect the randomized controlled trials (RCTs) about trazodone vs. alprazolam for adults’ GAD. According to the inclusion and exclusion criteria, two reivewers screened literature, extracted data and assessed the quality of the included studies, then meta-analysis was conducted using RevMan 5.0 software. Results A total of 5 RCTs involving 403 patients were included. The results of meta-analysis showed that: a) After four-week treatment, there were no significant differences between the two groups in the HAMA scores (RR=1.04, 95%CI 0.95 to 1.13, P=0.38) and cure rate (RR=1.05, 95%CI 0.75 to 1.48, P=0.76); and b) The somnolence rate of the trazodone group was lower than that of the alprazolam group (RR=0.42, 95%CI 0.25 to 0.72, P=0.001). But there were no significant differences between the two groups in dizziness (RR=0.52, 95%CI 0.27 to 1.01, P=0.05), fatigue (RR=0.10, 95%CI 0.01 to 1.41, P=0.09), and poor appetite (RR=2.82, 95%CI 0.28 to 28.23, P=0.38). Conclusion There is no significant difference between razodone and alprazolam in the effectiveness when treating GAD, but razodone has lower side effects while alprazolam tends easily to cause somnolence. For the quantity limitation and low methodological quality of the included studies, this conclusion still needs to be further proved by more high quality RCTs.
The integral and individual-scale wavelet entropy of electroencephalogram (EEG) were employed to investigate the information complexity in EEG and to explore the dynamic mechanism of child absence epilepsy (CAE). The digital EEG signals were collected from patients with CAE and normal controls. Time-frequency features were extracted by continuous wavelet transformation. Individual scale power spectrum characteristics were represented by wavelet-transform. The integral and individual-scale wavelet entropy of EEG were computed on the basis of individual scale power spectrum. The evolutions of wavelet entropy across ictal EEG of CAE were investigated and compared with normal controls. The integral wavelet entropy of ictal EEG is lower than inter-ictal EEG for CAE, and it also lower than normal controls. The individual-scale wavelet entropies of 12th scale (centered at 3 Hz) of ictal EEG in CAE was significantly higher than normal controls. The individual-scale wavelet entropies for α band (centered at 10 Hz) of ictal EEG in CAE were much lower than normal controls. The integral wavelet entropy of EEG can be considered as a quantitative parameter of complexity for EEG signals. The complexity of ictal EEG for CAE is obviously declined in CAE. The wavelet entropies declined could become quantitative electrophysiological parameters for epileptic seizures, and it also could provide a theoretical basis for the study of neuromodulation techniques in epileptic seizures.