Objective Glycine acts as a co-agonist for the activation of N-methyl-D-aspartate receptors （NMDARs） by binding to glycine sites, thus potentiating glutamate-elicited responses and inhibiting NMDAR desensitization i...
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Objective Glycine acts as a co-agonist for the activation of N-methyl-D-aspartate receptors （NMDARs） by binding to glycine sites, thus potentiating glutamate-elicited responses and inhibiting NMDAR desensitization in a dose-dependent manner. The present study aimed to characterize the glycine-dependent inactivation of NMDARs and to explore its pathophysiological significance. Methods Primary hippocampal cell cultures from embryonic days 17-18 rats were treated with NMDA or NMDA plus glycine. Patch-clamp recording and intracellular Ca 2＋ imaging were performed to test the effects of glycine on NMDA-activated currents and increase of intracellular free Ca 2＋ respectively. Immunofluorescence staining was conducted to examine NR1 internalization. Cell damage was tested with MTT method and lactate dehydrogenase leakage. Results Glycine reduced the peak current and Ca 2＋ influx elicited by NMDA application at concentrations ≥300 μmol/L. This is a novel suppressive influence of glycine on NMDAR function, since it occurs via the NMDAR glycine-binding site, in contrast to the classic suppression, which occurs through the binding of glycine to glycine receptors. The level of membrane NMDARs was measured to evaluate whether internalization was involved. Immunohistochemical labeling showed that incubation with high concentrations of NMDA plus glycine did not change the expression of NMDARs on the cell surface when compared to the expression without glycine; hence the possibility of NMDAR internalization primed by glycine binding was excluded. Conclusion In summary, the novel suppressive effect of glycine on NMDARs was mediated via binding to the glycine site of the NMDAR and not by activation of the strychnine-sensitive glycine-receptor-gated chloride channel or by the internalization of NMDARs. The inhibitory influence of glycine on NMDARs adds a new insight to our knowledge of the complexity of synaptic transmission.
This study describes the use of the weighted multiplicative algebraic reconstruction technique(WMART)to obtain vertical ozone profiles from limb observations performed by the scanning imaging absorption spectrometer f...
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This study describes the use of the weighted multiplicative algebraic reconstruction technique(WMART)to obtain vertical ozone profiles from limb observations performed by the scanning imaging absorption spectrometer for atmospheric chartography(SCIAMACHY).This technique is based on SaskMART(the combination of the multiplicative algebraic reconstruction technique and SaskTRAN radiative transfer model),which was originally developed for optical spectrometer and infrared imaging system(OSIRIS)*** of the objectives of this study was to obtain consistent ozone profiles from the two *** this study,the WMART algorithm is combined with a radiative transfer model(SCIATRAN),as well as a set of measurement vectors comprising five Hartley pairing vectors(HPVs)and one Chappuis triplet vector(CTV),to retrieve ozone profiles in the altitude range of 10–69 *** that the weighting factors in WMART have a significant effect on the retrievals,we propose a novel approach to calculate the pair/triplet weighting factors using wavelength weighting *** results of the application of the proposed ozone retrieval scheme are compared with the SCIAMACHY v3.5 ozone product by University of Bremen and validated against profiles derived from other passive satellite observations or measured by *** 18 and 55 km,the retrieved ozone profiles typically agree with data from the SCIAMACHY ozone product within 5%for tropics and middle latitudes,whereas a negative deviation exists between 35 and 50 km for northern high latitudes,with a deviation of less than 10%above 50 *** of the retrieved profiles with microwave limb sounder(MLS)v5.0 indicates that the difference is within±5%between 18 and 55 km,and an agreement within 10%is achieved in other altitudes for tropics and middle *** of the retrieved profiles with OSIRIS v7.1 indicates that the average deviation is within±5%between 20 and 59 km,and difference of approximately 10%is
Objective This study was to report our early experience with electrical isolation of pulmonary vein (PV) in paroxysmal atrial fibrillation (AF) by using a circular cryoablation catheter. Methods After electroanatomic ...
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Objective This study was to report our early experience with electrical isolation of pulmonary vein (PV) in paroxysmal atrial fibrillation (AF) by using a circular cryoablation catheter. Methods After electroanatomic model of LA/PVs was established by Carto, cryoablation was performed in each PV. If complete isolation of PVs could not be achieved, then additional radiofrequency ablations would be applied to ablate the conduction gaps. Results Cryoablation was performed in totally 58 PVs in 14 cases with paroxysmal AF. Thirty-one PVs (53.4%) were successfully isolated with the single use of the circular cryoablation catheter after 2 to 5 (3.2±1.5) cryoablation, while 2 to 4 additional radiofrequency ablations needed to be applied at gaps on the circular cryoablation lines to achieve completely isolation in 27 PVs (46.6%). After a follow up of 18±7 months, 11 patients (78.6%) remained AF free. Selective pulmonary venography immediately and repeat magnetic resonance imaging (MRI) scan at 3 months post procedure showed there was no PV stenosis. Conclusion The circular cryoablation catheter can be safely used in the isolation of PVs in paroxysmal AF, But the efficacy of this technique needs to be further improved.
AIM:To determine the antiviral mechanism or target of oxymatrine against hepatitis B virus(HBV).METHODS:HepG2.2.15 cells were incubated with culture medium containing 500 μg/mL of oxymatrine for 2 and 5 *** surface a...
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AIM:To determine the antiviral mechanism or target of oxymatrine against hepatitis B virus(HBV).METHODS:HepG2.2.15 cells were incubated with culture medium containing 500 μg/mL of oxymatrine for 2 and 5 *** surface antigen of HBV(HBsAg) and e antigen of HBV(HBeAg) in supernatant were determined by *** DNA in supernatant,and intracellular covalently closed circular DNA(cccDNA),relaxed circular DNA(rcDNA) and pregenomic RNA(pgRNA) were quantif ied by specif ic real-time polymerase chain reaction(PCR) or reverse transcription(RT)-***:Treatment with oxymatrine for 2 d and 5 d reduced the production of HBV by the cell line,as indicated by the decline of HBsAg(22.67%,t = 5.439,P = 0.0322 and 22.39%,t = 5.376,P = 0.0329,respectively),HBeAg(55.34%,t = 9.859,P = 0.0101 and 43.97%,t = 14.080,P = 0.0050) and HBV DNA(40.75%,t = 4.570,P = 0.0447 and 75.32%,t = 14.460,P = 0.0047) in the *** cccDNA was also markedly reduced by 63.98%(t = 6.152,P = 0.0254) and 80.83%(t = 10.270,P = 0.0093),and intracellular rcDNA by 34.35%(t = 4.776,P = 0.0413) and 39.24%(t = 10.050,P = 0.0097).In contrast,intracellular pgRNA increased by 6.90-fold(t = 8.941,P = 0.0123) and 3.18-fold(t = 7.432,P = 0.0176) after 500 μg/mL of oxymatrine treatment for 2 d and 5 d,***:Oxymatrine may inhibit the replication of HBV by interfering with the process of packaging pgRNA into the nucleocapsid,or inhibiting the activity of the viral DNA polymerase.
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