212 research outputs found
Effect of low intensity white light irradiation on the retinas of mice
AIM: To investigate the effect of low intensity white light irradiation on the retinas of mice.<p>METHODS: Thirty C57BL/6J mice were randomly divided into two groups. The number of the mice in each group was 15. The mice in experimental group received dark adaptation from 5:00p.m. to 6:00p.m.,and then exposed to LED white light from 6:00p.m. to 7:00p.m. everyday for a month. At 1, 3, 7, 14 and 30d after the beginning, we examed the histology of mice retinas, calculated the thickness of outer nuclear layer(ONL),inner nuclear layer(INL)and analyzed electrophysiology of mice.<p>RESULTS:One month after experiment, compared to the control group, the latency of Rod-R a wave of the mice in experimental group significantly prolonged, the amplitude of Cone-R b wave of the mice in experimental group significantly decreased and the latency of b wave of the mice in experimental group significantly prolonged(<i>P</i><0.05).There are no significant difference in the histology of retina, ONL and INL thicknesses.<p>CONCLUSION: 100lux low intensity white light could give rise to the impairment of the retinal functions in dark-adapted mice
A Multi-Agent-Based System for eProcurement
E-procurement has become an important function of enterprise information systems. The process of e-procurement includes automatic definition of product requirements, search and selection for suppliers, negotiation and contracting with suppliers. In this paper, we propose a novel agentbased architecture for e-procurement system, in which various agents take such responsibilities as negotiating and contracting. Moreover, the architecture that we propose can monitor transaction status and enhance the flexibility to handle unexpected exceptions, thus leading to agile procurement management
Modified scleral puncture drainage in 23G vitrectomy for patients with coexisting rhegmatogenous retinal detachment and choroidal detachment
AIM: To observe and analyze the safety and clinical efficacy of full-thickness scleral incision and in situ paracentesis in the treatment of patients with coexisting rhegmatogenous retinal detachment and choroidal detachment using minimally invasive vitrectomy. METHODS: From April 2015 to April 2017, 20 patients(20 eyes)with coexisting rhegmatogenous retinal detachment and choroidal detachment who were treated in Department of Ophthalmology, Jiangsu Province Hospital were enrolled in this retrospective analysis. All patients received modified scleral puncture drainage combined with 23G minimally invasive vitrectomy. This study analyzed and compared intraoperative paracentesis success rate, the incidence of intraoperative, postoperative visual acuity, intraocular pressure, and postoperative retinal reattachment rate. RESULTS: Suprachoroidal fluid from all patients were drainaged successfully. Compared with preoperative conditions, the postoperative visual acuity was significantly improved(PPCONCLUSION: The modified scleral puncture surgery in the treatment of patients with coexisting rhegmatogenous retinal detachment and choroidal detachment in 23G vitrectomy has great clinical effects. It not only simplifies the procedure of operation, but also reduces the difficulty and complication of operation
Progress of inhibiting epithelial-mesenchymal transition in retinal pigment epithelial cells
Epithelial-mesenchymal transition(EMT)of retinal pigment epithelial cells(RPE)plays a key role in proliferative vitreoretinopathy(PVR), and also decreases the therapeutic effect of anti-vascular endothelial growth factor(anti-VEGF)to choroidal neovascularization(CNV). In addition, cells transplantation has been becoming a potential therapeutic method to treat age-related macular degeneration(AMD), and some cells sources like human embryonic stem cells(hESC)or induced pluripotent stem cell(iPSC)induced RPE cells, and fetal RPE cells have been attempted. However, EMT, as a common problem, decreases cells proliferation and differentiation efficiency, and it will reduce therapeutic effect and the number of therapeutic populations. So, in this article, we reviewed some possible methods to inhibit EMT
Graphene Field-Effect Transistor for Terahertz Modulation
The real-world applications of terahertz (THz) technology necessitate versatile adaptive optical components, for example, modulators. In this chapter, we begin with a brief review on different techniques for THz modulation. After that, we introduce the extraordinary features of graphene along with its advantages and disadvantages as channel materials for field effect transistor (FET). We then discuss two types of graphene FET-based THz modulators, one is rigid and another is flexible. The feasibility of the high-quality THz modulators with different graphene FET structures has been successfully demonstrated. It is observed that by tuning the carrier concentration of graphene by electrical gating, the THz modulation can be obtained with relatively large modulation depth, broad width band, and moderate speed. This chapter helps the reader in obtaining guidelines for the proper choice of a specific structure for THz modulator with graphene FET
Crystal Structures of Phosphodiesterases 4 and 5 in Complex with Inhibitor 3-Isobutyl-1-methylxanthine Suggest a Conformation Determinant of Inhibitor Selectivity
Cyclic nucleotide phosphodiesterases (PDEs) are a superfamily of enzymes controlling cellular concentrations of the second messengers cAMP and cGMP. Crystal structures of the catalytic domains of cGMP-specific PDE5A1 and cAMP-specific PDE4D2 in complex with the nonselective inhibitor 3-isobutyl-1-methylxanthine have been determined at medium resolution. The catalytic domain of PDE5A1 has the same topological folding as that of PDE4D2, but three regions show different tertiary structures, including residues 79-113, 208-224 (H-loop), and 341-364 (M-loop) in PDE4D2 or 535-566, 661-676, and 787-812 in PDE5A1, respectively. Because H- and M-loops are involved in binding of the selective inhibitors, the different conformations of the loops, thus the distinct shapes of the active sites, will be a determinant of inhibitor selectivity in PDEs. IBMX binds to a subpocket that comprises key residues Ile-336, Phe-340, Gln-369, and Phe-372 of PDE4D2 or Val-782, Phe-786, Gln-817, and Phe-820 of PDE5A1. This subpocket may be a common site for binding nonselective inhibitors of PDEs
Hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin inhibits the proliferation of ARPE-19 cells
<p>Abstract</p> <p>Background</p> <p>The antiproliferative effect of the Hsp90 inhibitor 17-AAG (17-allylamino-17-demethoxygeldanamycin) on human retinal pigment epithelial cells is investigated.</p> <p>Methods</p> <p>MTT and flow cytometry were used to study the antiproliferative effects of the 17-AAG treatment of ARPE-19 cells. 2D gel electrophoresis (2-DE) and mass spectrometry were applied to detect the altered expression of proteins, which was verified by real-time PCR. Gene Ontology analysis and Ingenuity Pathway Analysis (IPA) were utilized to analyze the signaling pathways, cellular location, function, and network connections of the identified proteins. And SOD assay was employed to confirm the analysis.</p> <p>Results</p> <p>17-AAG suppressed the proliferation of ARPE-19 cells by inducing cell cycle arrest and apoptosis. Proteomic analysis revealed that the expression of 94 proteins was altered by a factor of more than 1.5 following exposure to 17-AAG. Of these 94, 87 proteins were identified. Real-time PCR results indicated that Hsp90 and Hsp70, which were not identified by proteomic analysis, were both upregulated upon 17-AAG treatment. IPA revealed that most of the proteins have functions that are related to oxidative stress, as verified by SOD assay, while canonical pathway analysis revealed glycolysis/gluconeogenesis.</p> <p>Conclusions</p> <p>17-AAG suppressed the proliferation of ARPE-19 cells by inducing cell cycle arrest and apoptosis, and possibly by oxidative stress.</p
Structures of the N-Terminal and Middle Domains of E. coli Hsp90 and Conformation Changes upon ADP Binding
Hsp90 is an abundant molecular chaperone involved in many biological systems. We report here the crystal structures of the unliganded and ADP bound fragments containing the N-terminal and middle domains of HtpG, an E. coli Hsp90. These domains are not connected through a flexible linker, as often portrayed in models, but are intimately associated with one another. The individual HtpG domains have similar folding to those of DNA gyrase B but assemble differently, suggesting somewhat different mechanisms for the ATPase superfamily. ADP binds to a subpocket of a large site that is jointly formed by the N-terminal and middle domains and induces conformational changes of the N-terminal domain. We speculate that this large pocket serves as a putative site for binding of client proteins/cochaperones. Modeling shows that ATP is not exposed to the molecular surface, thus implying that ATP activation of hsp90 chaperone activities is accomplished via conformational changes
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