1. A neuronal molecular switch through cell-cell contact that regulates quiescent neural stem cells
Journal of Shanghai Jiaotong University(Medical Science) 2019;39(4):339-341
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.
2.Simulation of extracellular electrical stimulation of rat optic nerve fiber based on experimental data
Jie GAO ; Qingli QIAO ; Nan XIE
Chinese Journal of Tissue Engineering Research 2010;14(9):1629-1633
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.
3.Antiinflammatory and Bacteriostasis Pharmacodynamics Effects Research of Sanxiaoyuchuang Ointment
Jie ZHANG ; Nan ZHANG ; Haitao GE
Chinese Journal of Information on Traditional Chinese Medicine 2008;0(S1):-
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.
4.Pharmacokinetics of teicoplanin in rabbit eyes
Li-na, MAO ; Na, LIU ; Yu, LUO ; Jie, LI ; Nan-nan, DU
Chinese Journal of Experimental Ophthalmology 2012;30(7):621-624
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.
5.A daily quality assure procedure for the on board imager and analysis of the results
Qiu GUAN ; Nan LI ; Nan LIU ; Tingtian PANG ; Jie QIU ; Fuquan ZHANG
Chinese Journal of Radiation Oncology 2012;(6):560-562
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.
6.APPLICATION OF FLUORESCENCE IN SITU HYBRIDIZATION (FISH) IN MICROBIAL ECOLOGY
De-Feng XING ; Nan-Qi REN ; Ai-Jie WANG ;
Microbiology 1992;0(06):-
Molecular technologies are sensitive, fast, and cheap in the study on microbial ecology. However, these methods do not provide information about morphology, number, and spatial distribution of the microorganisms. In contrast, Fluorescence in situ hybridization (FISH) combines the precision of molecular biology with the visual information from microscope, and permits visualization and identification of individual miciobial cells within their natural habitat. FISH not only allows the detection of slow growing microorganisms, but also of yet-to-be cultured. It is useful for many applications in diagnosis and assessment of the population structure of complex microbial communities, and is a powerful tool for molecular ecology studies in microbiology, In this paper, major techniques and progresses of FTSH were described. Its application in microbial ecology, as well as problems , pitfalls, and perspectives of FISH are discussed.
7.Therapeutic mechanisms of tumor necrosis factor-? monoclonal antibody on hepatopulmonary syndrome in rats
Li LIU ; Zhi ZHAO ; Nan LIU ; Yali WU ; Jie FU
Chinese Journal of Pathophysiology 1989;0(06):-
AIM: To investigate the expression of iNOS in the lung of HPS rats treated with tumor necrosis factor-? monoclonal antibody(TNF-?-McAb) and to investigate the therapeutic mechanism of TNF-?-McAb on hepatopulmonary syndrome.METHODS: Male Sprague-Dawley rats,weighing(250?25)g,were randomized to sham operation group,common bile duct ligation(CBDL) group and CBDL+TNF-? McAb treatment group.Histopathological changes of the lung tissue were evaluated by hematoxylin and eosin staining.The mRNA expression of iNOS in the lungs of hepatopulmonary rats was examined by RT-PCR,while the changes of iNOS in the protein level were evaluated by immunohistochemistry and Western blotting.RESULTS: The inflammatory responses in the CBDL rats treated with TNF-?-McAb decreased than that in CBDL group.Compared to CBDL group,the distribution of iNOS protein and the mRNA expressions in the lung tissue in TNF-?-McAb group were inhibited.CONCLUSION: TNF-?-McAb inhibits the expression of iNOS and plays a role in the treatment of HPS.
8.Progress in Structural and Functional Study of Ubiquitin Ligases
Na YANG ; Qiaoming HOU ; Jie NAN ; Xiaodong SU
Progress in Biochemistry and Biophysics 2006;0(01):-
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.
9.The value of contrast enhanced ultrasound in diagnosing type Ⅰ and Ⅱ endoleaks after endovascular abdominal aortic aneurysm repair
Jie ZHANG ; Xiangchen DAI ; Ming XIAO ; Nan KANG ; Jiangqiong CHEN
Chinese Journal of Ultrasonography 2017;26(4):296-301
Objective To investigate the role of contrast enhanced ultrasound (CEUS) in detecting type Ⅰ and Ⅱ endoleaks after endovascular abdominal aortic aneurysm repair (EVAR).Methods PostEVAR patients who met the inclusion criteria were enrolled.All of patients underwent CEUS and computer tomography angiography (CTA) examination.The following parameters were evaluated:ultrasound contrast agent within aneurysmal sac,location and source of endoleaks,wash-in time of endoleaks and stentgraft since contrast agent injection.Analysis was performed to observe different types of endoleak features in CEUS.Results Nine cases were enrolled and all the cases had endoleaks.Three cases were type Ⅰ,6 cases were type Ⅱ.The wash-in time of type Ⅱ endoleaks delayed 9.8 seconds compared to type Ⅰ,and the results of CEUS diagnosis were consistent with CTA.Conclusions CEUS is an effective way to detect endoleaks.This technique can be used as a supplement for CTA in follow-up of post-EVAR patients.
10.Effects of intravitreous injection of different drugs combined with laser photocoagulation for macular edema secondary to retinal vein occlusion
Jie, YANG ; Nan-Xiang, PENG ; Ji-Sheng, CHEN
International Eye Science 2017;17(10):1912-1914
AIM: To evaluate the effects and safety of intravitreal injection of triamcinolone acetonide ( TA ) or conbercept combined with macular laser grid photocoagulation in the treatment of macular edema secondary to retinal vein occlusion( RVO) . ·METHODS: Fifty cases ( 50 eyes ) with macular edema secondary to retinal vein occlusion were selected and assigned to 2 groups: intravitreal injection of TA or conbercept, and laser photocoagulation after 7d. Best corrected visual acuity ( BCVA ) , fundus examination, optical coherence tomography ( OCT ) and intraocular pressure ( IOP ) were examined before intravitreous injection and 14d, 1 and 3mo after laser, fundus fluorescein angiography(FFA) were examined 3mo after treatment. The postoperative results at each time point were compared with preoperative values. · RESULTS: Two kinds of treatment compared with preoperative, the BCVA all increased in various degrees. At 14d after intravitreous injection, 1 and 3mo after laser, the ratio of vision improved in TA group was 76%, 80%, 68%, conbercept group was 88%, 92%, 88%, BCVA of two groups in each period all had varying degrees of increase than preoperative. The best BCVA acquired at 1mo after treatment. The macular thickness after treatment was significantly lower than preoperative in two groups. At preoperative, 14d, 1 and 3mo after treatment, the macular thickness in TA group was 557. 5 ± 150. 9,301. 7±120. 1, 262. 7 ± 131. 2, 338. 1 ± 146. 5μm; the macular thickness in conbercept group was 569. 4 ± 135. 9, 282. 3 ± 133. 5, 259. 5 ± 116. 4, 307. 8 ± 122. 6μm. The macular thickness of the two groups were significantly different between preoperative and postoperative. · CONCLUSION: The combination of intravitreous injection of TA or conbercept with macular laser grid photocoagulation can be an effective method in the treatment of macular edema secondary to RVO, conbercept treatment is more effective and security.