The quiescence of radial neural stem cells (rNSCs) in adult brain is regulated by environmental stimuli. However, little is known about how the neurogenic niche couples the external signal to regulate activation and transition of quiescent rNSCs. Here, we reveal that long-term excitation of hippocampal dentate granule cells (GCs) upon voluntary running leads to activation of adult rNSCs in the subgranular zone and thereby generation of newborn neurons. Unexpectedly, the role of these excited GC neurons in NSCs depends on direct GC-rNSC interaction in the local niche, which is through down-regulated ephrin-B3, a GC membranebound ligand, and attenuated transcellular EphB2 kinase-dependent signaling in the adjacent rNSCs. Furthermore, constitutively active EphB2 kinase sustains the quiescence of rNSCs during running. These findings thus elucidate the physiological significance of GC excitability on adult rNSCs under external environments and indicate a key-lock switch regulation via cellcell contact for functional transition of rNSCs.

BACKGROUND:Currently,there are three types of visual prosthesis:retinal prosthesis,optic nerve prosthesis and visual cortical prosthesis.Normal optic nerve fiber is the basis to apply visual prosthesis.Extracellular stimulation of myelinated optic nerve fiber is developed from intracellular stimulation,with feasible selection of stimulation locations and low requirements for operation.OBJECTIVE: Using computer to simulate the response of myelinated rat optic nerve fiber to extracellular point current source and to analyze the effect of the position of the point source on the response of the optic nerve fiber.METHODS:The experiment data of ion channels of rat optic nerve fiber and the characteristic of common ion channels were summarized,and the existing Hodgkin-Huxley like optic nerve fiber models were analyzed.The response of the optic nerve fiber model was simulated by computer,and the differences of action potentials of Ranvier node were compared by changing the position of point source.RESULTS AND CONCLUSION:Simulated models showed that the response of optic nerve is affected by the position of extracellular exciting electrode.The myelinated rat optic nerve fiber is easier to activate when the distance between point source and the Ranvier node center of the optic nerve fiber is short.

Objective To observe the effects of Sanxiaoyuchuang ointment on the mice inflammatory model induced by Dimethylbenzene,bacteria strains in vitro and mice pneumococcus pneumonia model.Methods Mice inflammatory model induced by Dimethylbenzene,in vitro bacteria strains model and mice pneumococcus pneumonia model were founded respectively,randomed and controlled methods were used,exposed to different dosages of Sanxiaoyuchuang ointment,the changes of auricle swelling degree,earcapillary vessel permeability,the growth rate of strains and pneumococcus pneumonia mice's mortality were measured.Results 8% dose Sanxiaoyuchuang group had obvious inhibition effects on mice auricle swelling induced by Dimethylbenzene,it had no obvious difference compared with Jingwanhong group.It could also lower the mice earcapillary vessel permeability,inhibit or eradicate the colon bacillus,Staphylococcus aureus,cyanomycosis,Sonne dysetery,typhoid bacillus,and decrease the mortality rate of mice intraperitoneal injected by pneumococcus.Conclusion Sanxiaoyuchuang ointment has good antiinflammatory and bacteriostasis(in vivo and in vitro) pharmacodynamics effects.

Objective Performing a daily quality assure (QA) program to get variation and error range of on board imager (OBI) system,so that the OBI system can meet the needs of clinical treatment.Methods The daily QA program including: mechanical accuracy,2D/2D Shift calculations accuracy,couch motion accuracy.Results The max deviation was-0.7 mm in lcft-right (LR) dircction and 0.8 mm in superior-inferior (S1) direction in Linac& OBI isocenter accuracy check.The max deviations in 4 blades (x1,x2,y2,y1) position accuracy check were:-2.1 mm,2.2 mm,± 1.7 mm,-2.1 mm.In OBI mechanical arms position accuracy check,31％ standard data was 85.2 cm with 0 mm deviation; 69％ standard data was 85.1 cm with 1 mm deviation.In LR,SI and anterior-posterior direction,2D/2D shift calculations accuracy was 0.46 mm,1.35 mm,-0.04 mm and couch motion accuracy was-0.1 mm,0.3 mm,0.2 mm,respectively.Conclusions By performing the daily QA program,it could be found whether OBI works properly and satisfies the clinical use.The physicist can pay more attention to the parameters which change frequently,and adjust the frequency of the parameters which are stable,so that working efficiently.

Background Endophthalmitis is a serious infectious eye disease.Efficient drug therapy plays a key role in the early stage.There have been few researches on teicoplanin treating endophthalmitis and pharmacokinetics in ocular tissue.Objective The present study was to investigate the intraocular pharmacokinetic course and feature of intravitreal administration of teicoplanin.Methods Thirty-three Japanese white rabbits were included in this study and randomized into 6 groups.The right eyes of the rabbits were used in experiment.5 g/L of teicoplanin was injected into the vitreous cavity,and vitreous and aqueous humor samples were extracted after 15 minutes,30 minutes,1,2,4,6,12,24,48,96 and 192 hours,and the concentration of teicoplanin was determined by bioassay.Results The logarithmic value of the concentration of teicoplanin was raised with the increase in the bacterial inhibition zone diameters,of which the equation of the regression curve was Y =0.174X-0.813(R2=0.999).A good linear relationship was presented within 1.0-80.0 mg/L.Single intravitreal injection of teicoplanin was compliant with the two-compartment model.Moreover,the distribution phase Tα1/2 and elimination phase Tβ1/2 of vitreous were 1.68 and 152.15 hours,separately.And Tα1/2 and Tβ1/2 of the aqueous humor were 2.83 hours and 70.56 hours,individually.The peak teicoplanin concentrations in the vitreous and aqueous humor were(358.47±21.53)mg/L and(102.17±9.54)mg/L at 1 hour,respectively and remained at(4.38±0.68)mg/L and(2.38±0.38)mg/L,respectively 192 hours later.Conclusions Intravitreal injection of 0.5 mg of teicoplanin can remain therapeutic concentration for a long time in the vitreous and aqueous humor.

Objective To investigate the survival rate of patients with chronic severe hepatitis B (CSH) after lamivudine treatment. Method A matched retrospective cohort study using data on patients derived from a prospectively collected chronic severe hepatitis B database was conducted. The database included patients who received or did not receive lamivudine treatment from October, 1999 to December, 2003. The match was conducted according with 3 variables: sex, age and duration of disease. The match ratio was 1∶1. Cases were patients who received lamivudine treatment (n=103).Controls were patients who did not receive lamivudine treatment (n=103). All the patients were followed up and their median survival time and survival rate were compared and evaluated. Results The median survival time in lamivudine treatment group and control group were 85 and 35 d respectively. The survival rate for 3 years in treatment group and control group were 42.7% and 23.4% respectively. There was significance difference in survival rate between the 2 groups (P

Objective To explore the related factors with plasma neuropeptide Y in 180 normal healthy people by stepwise regression analysis. Methods Right ventricular end-diastolic diameter(RVDD),inter-ventricular septum end-diastolic thickness(IVST),left ventricular end-diastolic diameter(LVDD),left ventricular posterior wall end-diastolic thickness(LVPWT),ejection fraction(EF),strole volume(SV),cardiac output(CO),cadiac output index(CI),stroke volume index(SI) and plasma neuropeptide Y were measured respectively by echocardiography and immunoradioassay in all subjects. In addition,we examined the height,weight,blood pressure,heart rate and subcutaneous fat thickness in every subjects. Results The plasma neuropeptide Y wasn't significant difference in different gender and age(P≥0.05). The plasma neuropeptide Y of healthy population was normal distribution and the 95% of confidence interval 70.27 to 190.61,and 99% of confidence interval was 51.23 to 209.65. Conclusion The EF,height,LVST,diastolic blood pressure,CO,SV and subcutaneous fat thickness were the major related-factors of neuropeptide Y in plasma. The EF and height were negatively correlated with plasma neuropeptide Y,and other five factors were postive correlated with it.

Problem-based learning(PBL)brought many changes in the teaching model of medical education.This article explored the clinical application of PBL combined with picture archiving communicate system(PACS)in medical imaging education.Through comparing the results before and after periodic study,PBL was verified to motivate the students'learning interest.Enthusiasm of autonomic learning and problem analysis ability of students increased evidently,which provided a substantial basis for continued learning.

Objective To investigate the expression and diagnostic significance of CK19,CD56 and p53 protein in papillary thyroid microcarcinoma and thyroid papillary hyperplasia.Methods The expressions of CK19、CD56 and p53 protein were detected in 52 cases of papillary thyroid microcarcinoma and 31 of thyroid papillary hyperplasia by iImmunohistochemical methods.Results The positive rate of CK19 expression was 100 ％ (52/52) of papillary thyroid microcarcinoma and 29.0 ％ (9/31) in 31 of thyroid papillary hyperplasia.There was significant difference between two groups (P ＜ 0.001).CK56 in 2 cases (3.8 ％) of papillary thyroid microcarcinoma appeared mild positive expression,and in 20 cases (66.7 ％) of thyroid papillary hyperplasia positive expression (P ＜ 0.001).The positive expression rates of p53 were 69.2 ％(36/52) in papillary thyroid microcarcinoma and 6.5 ％ (2/31) in thyroid papillary hyperplasia (P ＜ 0.001).Conclusion CK19,CD56 and p53 may be important value on differential diagnosis of papillary thyroid microcarcinoma from thyroid papillary hyperplasia,and they are the indispensable markers of differential diagnosis.

Ubiquitination on target proteins is the signal of cellular protein degradation.Ubiquitin ligase E3 is one of the key enzymes in ubiquitination,it recognizes a specific substrate protein and recruits an ubiquitin conjugating enzyme E2,mediating the ubquitin transfer from the E2 to the substrate protein.Ubiquitin ligase E3 can be divided into two subfamilies according to their different structure characters and function mechanisms,the HECT(homologous to E6AP C terminus) family and the RING-finger family.Members of the HECT E3 share the common HECT catalytic domain,which can bind to an E2 and load the ubiquitin on themselves before catalyzing the transfer of ubiquitin to the target proteins.While the RING-finger E3 all contain an similar E2 binding domain and a unique substrate binding part,mediating direct ubiquitin transfer from the E2 to the substrate.The most recent progresses in the stuctural and functional studies of these two E3 famlies were summarized.