ObjectiveTo establish a central nervous system axonal mechanical transection model in vitro and observe the axonal regeneration style and speed following the transection. MethodsThe cortical explants the mice were cultured in vitro,of which the axon and dendrite parts were marked using immunofluorescence.The model was built by mechanically transecting the axons and removing the severed axons.The axonal regeneration style was observed by tracing the undeveloped cellular bodies adhering to the residual axonal surface.The growth speed of the regenerated axons and normal axons were measured as well.Results ( 1 ) After mechauically transecting the axons of explants,the axonal regeneration was largely founded at the transected line.The undeveloped cellular bodies went over the transected line and spread to the distal area with axonai regeneration. (2) The axonal growth speed was (118 ± 32) μm/d and (72 ±41) μm/d in the transection group,but was (41 ± 17) μm/d and (32 ± 19) μm/d in the control group at 24 and 48 hours respectively. ConclusionThe regeneration style of the transected axons is the extension of the axonal stumps,rather than sprouting growth,and the growth speed is faster than that of the normal axons.

Objective:To establish a method for the determination of benzene, chlorine alcohol and pyridine residues in piperazine ferulate. Methods:GC was used with a DB-624 (30 m × 0. 53 mm, 1. 0 μm) elastic quartz capillary column. The flame ionization detector was used with nitrogen as the carrier gas. The initial temperature was 50℃, maintaining for 5 min, and raised to 80℃ at the rate of 10℃·min-1 , and then raised to 200℃ at the rate of 50℃·min-1 , and maintaining for 4 minutes. The inlet temperature was 200℃, and the detector temperature was 220℃. The split ratio was 1 ∶1 and the injection volume was 1μl. The flow rate was 3 ml· min-1. Results:The linear range of benzene was 0.16-0.96 μg·ml-1(r=0.999 5), the average recovery was 95.7% (RSD =2.1, n=9), and the detection limit was 0.16 ng. The linear range of chlorine alcohol was 16.11-96.65 μg·ml-1(r=0.999 7), the average recovery was 97. 8% (RSD=2. 1, n=9), and the detection limit was 0. 62 ng. The linear range of pyridine was 15. 87-95. 23 μg·ml-1(r=0. 999 8), the average recovery was 99. 2% (RSD=1. 3, n=9), and the detection limit was 0. 15 ng. Con-clusion:The method is reliable, simple, accurate and stable, and suitable for the determination of benzene, chlorine alcohol and pyri-dine residues in piperazine ferulate.

Objective:To establish an HPLC method for the determination of related substances in piperazine ferulate. Methods:An HPLC method was used to determine the related substances in piperazine ferulate. The separation was performed on an Xtimate C18 column (250 mm × 4. 6 mm, 5 μm). The mobile phase was 0. 5% acetic acid-methanol-acetonitrile with gradient elution. The flow rate was 1. 0 ml·min-1 and the column temperature was 30℃. The detection wavelength was 286 nm and the injection volume was 20μl. Results:Ferulic acid had a good linear relationship within the range of 5-30 μg·ml-1(r=1.0000). The detection limit was 0. 02 ng. Conclusion:The method is reliable, simple, accurate, stable and durable, and suitable for the determination of related sub-stances in piperazine ferulate.

Objective To establish a model fit for axonal regeneration research after its mechanical injury.Methods Cortical explants from mice were planted on culture dishes by microglass pipettes or routine glass pipettes.The cell body and dendrites in axonal area were detected by immunofluorescence and RT-PCR.Besides,purity of regenerated axons was also tested by immunofluorescence and RT-PCR after mechanical transection of axons under microscopy.Results Compared with explants planting by routine glass pipettes,in the outside 1/2 axons of explants planted by micro-glass pipettes,the immunofluorescence and RT-PCR showed negative nucleus and dendrites.In the regenerated axons following mechanical transection of explants planted by micro-glass pipette,the immunofluorescene and RT-PCR showed no regenerated axons nucleus mixed into the dendrites and nucleus.Conclusions Explants planted by micro-glass pipette obtains enough pure axons and regenerated axons.The establishment of models of axonal mechanical transection lays foundation for its molecular study after trauma.

Objective To investigate effect of polymorphism of apolipoprotein E (APOE) gene on early apoptosis of astrocytes after hypoxic injury.Methods Astrocytes separated from APOE wild mice and APOE transgenic mice (ε3,ε4) were primarily cultured,and then purified and identified.Models of astrocyte hypoxic injury were set up by hypoxia.Morphological changes of astrocytes and mitochondria were observed by transmission electron microscope.Early apoptosis rate and changes of mitochondrial membrane potential were detected by flow cytometry.Results Cell foot process tumidness and mitochondria with irregular outline,vacuoles and irregular cristae were observed in each group by electron microscopy at six hours after hypoxia.There were no significant differences of cellular form changes among groups.Early apoptosis rate and decreasing degree of mitochondrial membrane potential in APOFε4 group were significantly higher than those in APOEε3 group and APOE wild group (P ＜ 0.05).Conclusion Compared with astrocytes from APOEε3 group and APOE wild group,mitochondrial membrane potential in astrocytes from APOEε4 group at early period after hypoxia declines more significantly,as may be one of causes for more astrocyte apoptosis.

The concentrations and distributions of trace metals and rare earth elements (REE) in sediment and mussel samples collected from the India Ocean hydrothermal area were analyzed.The metal correlation between organisms and sediments was investigated, and the ecological and chemical characteristics of REE were also explored.The results showed that, the trace metals in sediments were mainly Fe (96.6 mg/kg), Mn (1.14 mg/kg) and Zn (322.6 μg/kg), and Fe had high ratio of 98.15% by normalized calculation, which indicated that the available sediments in this studying hydrothermal area mainly consisted of iron ore substances.Trace metals and REE distributions all had good correlation between deep-sea sediments and deep-sea mussels, and the correlation coefficients were 0.991 for trace metals and 0.996 for REE.The contents and distributions of metal elements in deep-sea mussels were different from those in offshore mussels.The REE distributions in sediments and mussels showed obvious fractionation phenomenon, and the enrichment of LREE in mussels was significant.Through the REE patterns, Eu and Gd in sediments and mussels all showed anomalies, and Eu had a significant abnormal phenomenon in deep-sea sediments and deep-sea mussels.Besides, δEu values were 9.50, 10.68 and 0.23 in deep-sea sediments, deep-sea mussels and offshore mussels, respectively, and δCe were 2.21, 2.71 and 4.38, which showed that the enrichment sources of REE in offshore mussels and deep-sea mussels were different, and the REE in sediments and mussels from the India Ocean were homologous.

Background The underlying mechanism of choroidal neovascularization(CNV) is multifactorial and complex.Focal adhesion kinase(FAK) plays a crucial role in controlling essential cellular processes and influencing distinct steps of the angiogenic response.But to our knowledge,seldom study on the effect of FAK on CNV formation has been reported previously.Objective In this study,the effect of several CNV risk factors on the expression of FAK in cultured retinal pigment epithelium(RPE) cells was investigated to illuminate effect of FAK on CNV.Methods Human RPE cells were isolated from donor eyes and exposed to H2O2,swallow of outer segment of photoreceptors(POS) and extracellular matrix(ECM) separately with the treating as follows:RPE cells were co-cultured with 10,20,50 and 100μmol/L H2O2 for 20 days;POS(1×106/ml) were co-cultivated with RPE cells for 20 days(setting control group,POS group,hypoxia group with 200μmol/L CoCl2,and POS+hyoxia group);RPE cells were cultured on the plates coated with 100mg/L fibronectin(FN),laminin(LN) or collagen typeⅠfor 30minutes or 1 hour.The expression of FAK and pFAK in RPE cells were examined by Western blot analysis.Results FAK was highly expressed in the 20μmol/L and 50μmol/L H2O2 groups compared with control group(P＜0.01);while he expression level of pFAK was reduced after treated with H2O2 in comparison with the control group(P＜0.01).After cultured with POS for 20 days,the undigested lysosome could be observed in RPE cells.The expressions of FAK and pFAK in RPE cells were not significantly changed between control group and POS groups(P＞0.05),but those in hypoxia group were significantly up-regulated in comparison with control group(P＜0.01).Compared with the hypoxia group,the expression amount of pFAK was elevated in POS+hyoxia group(P＜0.01).In comparison with control group,the increased pFAK expression was seen in FN,LN and collagen typeⅠtreating for 1-hour groups(P＜0.05,P＜0.01).Conclusion FAK pathway participates in several CNV-initiated signaling,such as H2O2,POS and ECM,in cultured RPE cells.It is reasonable to believe that FAK potentially plays an important role in CNV-dependent disorder.

Objective To investigate the changes of electrode impedance,threshold(THR),maximum comfortable level(MCL),and dynamic range(DR),providing the basis for debugging after operation in congenital deaf children. Methods A respective study was carried out on 20 cases of congenital deaf children who were implanted with cochlear Med?EL SONATAti100. The measurements and changing ranges of electrode imped?ances,THR,MCL and dynamic range during the operation and at postoperative one month,three months,and six months were statistically analyzed. Results Electrode impedances were the lowest during the operation and the highest at one month after operation(P<0.01). The electrode imped?ance for the apical cochlear group was statistically different from that for other groups at one month(P<0.05). After three and six months,there were statistically significant differences between groups(P<0.01). THR at six months was lower than that at three months(P<0.05). MCL at three months was higher than that at one month(P<0.01). DR showed an increasing trend(P<0.05). There was no correlation of perioperative and post?operative electrode impedance with THR,MCL,and DR(P>0.05). Conclusion The electrode impedances varied due to different electrode posi?tion. The vales of THR,MCL and DR were unrelated with electrode impedance. DR was gradually increasing,MCL reached steady state earlier than THR. It is important that THR should be debugged at three months after operation and MCL should be debugged at six months.

Objective To investigate the safety and efficacy of intravenous thrombolysis (IVT) in elderly patients (aged≥80 years) with acute ischemic stroke.Methods From July 2014 to February 2016,157 consecutive patients with acute cerebral infarction treated with alteplase for intravenous thrombolysis within 4.5 h after onset at the Department of Neurology,the Third People's Hospital of Chengdu were collected retrospectively.They were confirmed by head CT or MRI.They were divided into a ≥80-year old group (n=47) and a <80-year old group (n=110) according to the age of onset.The baseline data were documented,including the risk factors for cardiocerebrovascular diseases,National Institute of Health stroke scale (NIHSS) score,onset to thrombolytic time (3.0-4.5 h),and application of anticoagulant drugs,etc.The adverse reactions of the patients were observed and the safety and efficacy of thrombolysis were evaluated,that is 7 d and 3 months mortality,symptomatic intracranial hemorrhage rate,and good recovery rates of intravenous thrombolysis at 24 h,1 week,and 3 months.Results (1) Compared with the <80-year old group,the ratio of atrial fibrillation and median age in the ≥80-year old group were higher.There were significant differences between the two groups (59.6% [n=28] vs.32.7% [n=36],83 [81,85] vs.67 [59,75] years old,all P<0.01).There were no significant differences in the remaining baseline data between the two groups (all P>0.05).(2) In the subtypes of cerebral infarction etiology,the proportion of cardiogenic embolism in the ≥80-year old group was higher than that in the <80-year old group.There was significant difference between the two groups (59.6% [n=28] vs.32.7% [n=36],P<0.01).There was no significant difference in the other etiological types between the two groups (all P>0.05).(3) There were no significant differences at one week (6.4% [n=3] vs.6.4% [n=7] respectively) and 3 months (12.8% [n=6] vs.9.1% [n=10]) in the mortality rates between the ≥80-year old group and the <80-year old group (all P>0.05).There were no significant differences in the proportions of intracranial hemorrhage (10.6% [n=5] vs.8.2% [n=9]) and symptomatic intracranial hemorrhage (4.3% [n=2] vs.6.4% [n=7]) between the two groups (all P>0.05).There was no significant difference between the good recovery rate at 24 h (38.3% [n=18] vs.45.5% [n=50]) and that at one week (53.2% [n=25] vs.62.7% [n=69];all P>0.05).The long-term (3 months) favorable prognosis rate in the ≥80-year old group was lower than that in the <80-year old group.There was significant difference between the two groups (51.1% [n=24] vs.71.8% [n=79], P<0.05).Conclusion For the onset within 4.5 h (aged≥80 years) in elderly patients with acute ischemic stroke,selecting the appropriate cases for intravenous thrombolysis is help to increase safety and early benefit.

Purpose To investigate the clinicopathological features of adolescent mixed epithelial and stromal tumor of the kidney ( MESTK) and improve recognization of this rare disease. Methods Clinicopathological and immunohistochemical characteristics of MESTK occured in 17-year-old girl were studied. Reviewed the related literatures, clinical and pathological characteristics of adoles-cent MESTK were analysed comprehensively. Results Congenital perineal spill was the main clinical manifestations. Microscopically, the tumor showed nodules and was composed of a mixture of epithelial and stromal elements. Glands were lined with columnar or cilia-ted columnar cells. Stromal cells surrounding glands seemed like ovaries and away from glands seemed like the differentiation of smooth muscle. Immunohistochemical staining revealed that the epithelial cells were positive for CK7 and vimentin. Stromal cells expressed desmin, smooth muscle actin ( SMA) , ER and PR. It was noteworthy that stromal cells away from glands expressed desmin. Conclu-sions As a kind of rare benign neoplasm of kidney, MESTK often occurs in perimenopausal women. But MESTK can also occur in ad-olescence, and has nothing to do with the use of hormone. Therefore, the renal tumor occurred in teenagers with biphasic differentiation should be differentiated from MESTK.