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1.
Retinal neovascularization (NV) is a major cause of blindness in ischemic retinopathies. Previous investigations have indicated that ischemia upregulates GFAP and PDGF-B expression. GFAP overexpression is a hallmark of reactive gliosis (RG), which is the major pathophysiological feature of retinal damage. In addition, PDGF-B has been implicated in proliferative retinopathies. It was the aim of this study to gain insights on the possible pharmacological interventions to modulate PDGF-B and GFAP expression, and its influence on RG and NV. We used an array of assays to evaluate the effects of YC-1, a small molecule inhibitor of HIF-1 and a novel NO-independent activator of soluble guanylyl cyclase (sGC), on RG and NV, in vivo and in vitro. When compared to the DMSO-treated retinas, dual-intravitreal injections of YC-1, in vivo: (1) suppressed the development and elongation of neovascular sprouts in the retinas of the oxygen-induced retinopathy (OIR) mouse model; and (2) reduced ischemia-induced overexpression of GFAP and PDGF-B at the message (by 64.14±0.5% and 70.27±0.04%) and the protein levels (by 65.52±0.02% and 57.59±0.01%), respectively. In addition, at 100 μM, YC-1 treatment downregulated the hypoxia-induced overexpression of GFAP and PDGF-B at the message level in rMC-1 cells (by 71.42±0.02% and 75±0.03%), and R28 cells (by 58.62±0.02% and 50.00±0.02%), respectively; whereas, the protein levels of GFAP and PDGF-B were reduced (by 78.57±0.02% and 77.55±0.01%) in rMC-1 cells, and (by 81.44±0.02% and 79.16±0.01%) in R28 cells, respectively. We demonstrate that YC-1 reversed RG during ischemic retinopathy via impairing the expression of GFAP and PDGF-B in glial cells. This is the first investigation that delves into the reversal of RG during ischemic retinal vasculopathies. In addition, the study reveals that YC-1 may exert promising therapeutic effects in the treatment of retinal and neuronal pathologies.  相似文献   

2.
Proliferative ischemic retinopathies such as proliferative diabetic retinopathy (PDR), retinopathy of prematurity (ROP) and those stemming from retinal vein occlusion are the leading causes of blindness in the working age and pediatric populations of industrialized countries. They present major financial burdens for health care systems and account for significant loss of productivity. These pathologies are characterized by excessive pre-retinal blood vessel growth that can ultimately lead to a fibrous scar formation and culminate in retinal detachment. This abnormal and disproportionate hyper-vascularization is a compensatory mechanism to overcome an earlier phase of microvessel degeneration and reinstate metabolic equilibrium to the hypoxic retina. To date, the treatment modalities to counter these diseases largely rely on invasive and moderately efficient surgical interventions. In this review, we discuss the current views on retinal vaso-obliteration, neovascularization and available treatments and present future strategies to tackle these diseases.  相似文献   

3.
Progressive outer retinal necrosis (PORN) syndrome is a form of the Varicella zoster virus (VZV) chorioretinitis found almost exclusively in people with the acquired immunodeficiency syndrome (AIDS). This destructive infection has an extremely rapid course that may lead to no light perception in affected eyes within days or weeks. Attempts at its treatment have had limited success. Rhegmatogenous retinal detachments often occur after the development of atrophic retinal holes, and silicone oil temponade has been found to be the most successful reattachment procedure. Unfortunately, cataract formation is common after such surgery. PORN needs to be differentiated from acute retinal necrosis (ARN) syndrome, a necrotizing retinitis that can also be caused by VZV. PORN and ARN are found at opposite ends of the spectrum of necrotizing herpetic retinopathies (NHR), where its clinical presentation depends upon immune system status. After a brief case presentation, the distinguishing clinical characteristics of PORN, its differentiation from ARN, attempts at its treatment, the role of the immune system status on its clinical appearance and treatment, and management of complications such as retinal detachment and subsequent cataracts are discussed.  相似文献   

4.
Abstract: The cellular events underlying various retinopathies are poorly understood but likely involve perturbation of retinal glucose metabolism. Current methods for assessing this metabolism are destructive, thus limiting longitudinal studies. We hypothesize that following an intravitreous injection, the clearance rate of a glucose analogue will be a nondestructive index of retinal glucose transport and metabolism in vivo. First, radiolabeled glucose analogues were injected into the vitreous. After 40 min, the dominant clearance path was posterior via the retina and was consistent with a facilitated transport mechanism. Next, either [6,6-2H2]glucose or 3-deoxy-3-fluoro- d -glucose was injected into the vitreous of rabbit eyes, and the clearance rate of each analogue was determined over 40 min using, respectively, 2H or 19F NMR. These rates were interpreted as a function of the retinal glucose transport and consumption. From the NMR data, the rate of retinal glucose consumption was ∼16 times slower than the transport of glucose. These data demonstrate that NMR measurements of glucose analogue clearance rate from the vitreous can provide a nondestructive index of retinal glucose transport and consumption in vivo.  相似文献   

5.
目的:2011年,我国糖尿病患者人数高达9240万。糖尿病视网膜病变(diabeticretinopathy,DR)作为糖尿病患者的常见并发症,在糖尿病人群中的患病率为37%,是导致成人获得性盲的最主要原因之一。严重增生性糖尿病视网膜病变以牵拉性视网膜脱离、玻璃体出血为特征,具有致盲率大,手术难度高等特点。针对与此,本文主要探讨术前注射贝伐单抗对23G玻璃体切割手术治疗严重增生性糖尿病视网膜病变患者效果的影响。方法:回顾性病例对照研究。共收集严重增生性糖尿病视网膜病变患者70例,药物辅助手术组(A组)21例,术前3—7天行玻璃体腔注射贝伐单抗(1.25mg/O.05mL);单纯手术组(B组)49例,行23G玻璃体切割术。分析两组术前及术后视力、手术时间、医源性裂孔、电凝、术后出血的不同。结果:在术后3月,两组视力提高有统计学意义(P〈O.05)。A组平均手术时间为74分钟,而B组平均手术时间为85分钟(P〉0.05)。医源性裂孔在A组中有1例,而B组中有16例(P〈0.05),在A组中有3例使用电凝,B组中有25例使用电凝(P〈0.05)。A组有1例出现术中及术后出血,B组为20例(P〈O.05)。结论:在这个回顾性研究中,我们发现对于严重增生性糖尿病视网膜病变的病人,术前玻璃体腔注射1.25mg/O.05ml贝伐单抗可以显著减少医源性裂孔的发生,减少术中电凝使用及术中术后出血的发生。  相似文献   

6.
The mechanism underlying vasoproliferative retinopathies like retinopathy of prematurity (ROP) is hypoxia‐triggered neovascularisation. Nerve growth factor (NGF), a neurotrophin supporting survival and differentiation of neuronal cells may also regulate endothelial cell functions. Here we studied the role of NGF in pathological retinal angiogenesis in the course of the ROP mouse model. Topical application of NGF enhanced while intraocular injections of anti‐NGF neutralizing antibody reduced pathological retinal vascularization in mice subjected to the ROP model. The pro‐angiogenic effect of NGF in the retina was mediated by inhibition of retinal endothelial cell apoptosis. In vitro, NGF decreased the intrinsic (mitochondria‐dependent) apoptosis in hypoxia‐treated human retinal microvascular endothelial cells and preserved the mitochondrial membrane potential. The anti‐apoptotic effect of NGF was associated with increased BCL2 and reduced BAX, as well as with enhanced ERK and AKT phosphorylation, and was abolished by inhibition of the AKT pathway. Our findings reveal an anti‐apoptotic role of NGF in the hypoxic retinal endothelium, which is involved in promoting pathological retinal vascularization, thereby pointing to NGF as a potential target for proliferative retinopathies.  相似文献   

7.

Background

Diabetic retinopathy and retinopathy of prematurity are diseases caused by pathological angiogenesis in the retina as a consequence of local hypoxia. The underlying mechanism for epiretinal neovascularization (tuft formation), which contributes to blindness, has yet to be identified. Neural cell adhesion molecule (N-CAM) is expressed by Müller cells and astrocytes, which are in close contact with the retinal vasculature, during normal developmental angiogenesis.

Methodology/Principal Findings

Notably, during oxygen induced retinopathy (OIR) N-CAM accumulated on astrocytes surrounding the epiretinal tufts. Here, we show that N-CAM ablation results in reduced vascular tuft formation due to reduced endothelial cell proliferation despite an elevation in VEGFA mRNA expression, whereas retinal developmental angiogenesis was unaffected.

Conclusion/Significance

We conclude that N-CAM exhibits a regulatory function in pathological angiogenesis in OIR. This is a novel finding that can be of clinical relevance in diseases associated with proliferative vasculopathy.  相似文献   

8.
RAGE and its ligands in retinal disease   总被引:1,自引:0,他引:1  
RAGE, the receptor for advanced glycation endproducts (AGEs), is a multiligand signal transduction receptor of the immunoglobulin superfamily of cell surface molecules that has been implicated in the pathogenesis of diabetic complications, neurodegenerative diseases, inflammatory disorders, and cancer. These diverse biologic disorders reflect the multiplicity of ligands capable of cellular interaction via RAGE that include, in addition to AGEs, amyloid-beta (Abeta) peptide, the S100/calgranulin family of proinflammatory cytokines, and amphoterin, a member of the High Mobility Group Box (HMGB) DNA-binding proteins. In the retina, RAGE expression is present in neural cells, the vasculature, and RPE cells, and it has also been detected in pathologic cellular retinal responses including epiretinal and neovascular membrane formation. Ligands for RAGE, in particular AGEs, have emerged as relevant to the pathogenesis of diabetic retinopathy and age-related macular disease. While the understanding of RAGE and its role in retinal dysfunction with aging, diabetes mellitus, and/or activation of pro-inflammatory pathways is less complete compared to other organ systems, increasing evidence indicates that RAGE can initiate and sustain significant cellular perturbations in the inner and outer retina. For these reasons, antagonism of RAGE interactions with its ligands may be a worthwhile therapeutic target in such seemingly disparate, visually threatening retinal diseases as diabetic retinopathy, age-related macular degeneration, and proliferative vitreoretinopathy.  相似文献   

9.
1.The objective of this study was to decipher whether proliferation of astrocytes and invasion of astrocytic processes into the retina could contribute to retinal detachment in a rabbit model.2.Cultures of astrocytes were injected intravitreally into the eyes of albino rabbits.3.Two weeks after injection, proliferation of astrocytes on the retinal surfaces was observed. Vascular endothelial growth factor (VEGF) and proliferative cell nuclear antigen (PCNA) were found by immunohistochemistry to be expressed in the center of the astrocytic growth.4.Using the same immunohistochemical technique to visualize glial fibrillary acidic protein (GFAP), a marker for astrocytes, processes of astrocytes in the growth were observed to penetrate into the host retina.5.Retinal detachment was then confirmed by ultrasound, histologically, and grossly 2 weeks after injection of astrocytes.6.Histochemistry on esterase indicated chloroesterase positive cells inside the growth. The secretion of this form of esterase might soften the vitreous and enhanced retinal detachment.7.Six weeks after injection, VEGF and PCNA decreased in the astrocytic growth but astrocytic processes still attached onto and penetrated the host retina.8.This study suggests that astrocytes could be a major factor in inducing retinal detachment.  相似文献   

10.
We undertook this study to evaluate the expression of septin family members SEPT5, SEPT8, and SEPT11 in proliferative retinal membranes. Epiretinal membranes (ERM) were obtained from seven patients with proliferative vitreoretinopathy (PVR) and from four patients and four postmortem eyes with proliferative diabetic retinopathy (PDR). Subretinal membranes (SRM) were obtained from one patient and six postmortem eyes. Membranes were examined by immunohistochemical staining of paraffin sections using polyclonal antibodies against SEPT5, SEPT8, and SEPT11 and an ABC detection system. SEPT8 expression was detected in all ERM and SRM, with an exceptionally strong expression of 100% for ERM of PVR, 63% for PDR membranes, and 57% for SRM. SEPT11 was identified in 91% of all cases, with strong expression of 14%, 25%, and 14% in ERM of PVR, PDR, and SRM, respectively. SEPT5 was seen in 54% of all cases; strong immunostaining was found in only one case of PVR membranes. Our finding suggests a role for members of the septin family in the development of proliferative retinal membranes.  相似文献   

11.
Neovascularization associated with diabetic retinopathy (DR) and other ocular disorders is a leading cause of visual impairment and adult-onset blindness. Currently available treatments are merely palliative and offer temporary solutions. Here, we tested the efficacy of antiangiogenic gene transfer in an animal model that mimics the chronic progression of human DR. Adeno-associated viral (AAV) vectors of serotype 2 coding for antiangiogenic Pigment Epithelium Derived Factor (PEDF) were injected in the vitreous of a 1.5 month-old transgenic model of retinopathy that develops progressive neovascularization. A single intravitreal injection led to long-term production of PEDF and to a striking inhibition of intravitreal neovascularization, normalization of retinal capillary density, and prevention of retinal detachment. This was parallel to a reduction in the intraocular levels of Vascular Endothelial Growth Factor (VEGF). Normalization of VEGF was consistent with a downregulation of downstream effectors of angiogenesis, such as the activity of Matrix Metalloproteinases (MMP) 2 and 9 and the content of Connective Tissue Growth Factor (CTGF). These results demonstrate long-term efficacy of AAV-mediated PEDF overexpression in counteracting retinal neovascularization in a relevant animal model, and provides evidence towards the use of this strategy to treat angiogenesis in DR and other chronic proliferative retinal disorders.  相似文献   

12.
Vascular endothelial growth factor (VEGF) and insulin-like growth factor-1 (IGF-1) have been implicated as important stimulatory factors for retinal neovascularization. In this study, we used intraocular gene transfer with gutless adenoviral (AGV) vectors to determine the effect of increased intraocular expression of VEGF, IGF-1, or sphingosine kinase (SPK), which produces sphingosine-1-phosphate, another angiogenic factor. Retinal neovascularization did not occur from intravitreous AGV-vectored VEGF, IGF-1, SPK, or combined VEGF and IGF-1, except occasionally adjacent to the retinal penetration site from the injection. However, corneal and iris neovascularization occurred after 2 weeks in all eyes injected with AGV.VEGF, but not those injected with only AGV.IGF-1 or AGV.SPK. These data suggest that the superficial capillary bed of the retina is relatively insensitive to VEGF, IGF-1, or SPK in adult mice, except when combined with retinal trauma. However, AGV-vectored VEGF is sufficient to consistently cause severe corneal and iris neovascularization. This provides a model for anterior segment neovascularization, which unlike previous models is relatively inexpensive and is not plagued by spontaneous regression, and therefore, may be useful for identification of new treatments.  相似文献   

13.
The proliferative activity of the pigment epithelium cells transplanted in the lens-less eyes was studied in the adult crested newt. The cells of transplanted pigment epithelium incorporated 3H-thymidine injected intraperitoneally. Within 10 days after explantation, the index of labelled nuclei equaled 27.8-34.0% and within 20 days the number of labelled cells doubled. By that time the proliferating transplant cells were depigmented and formed 2-3 rows of cells of retinal rudiment. In response to the removal of lens from the of recipients eyes their regeneration proceeded. Irrespective of participation (dorsal iris) or nonparticipation in lens regeneration (ventral iris), the index of labelled nuclei in these regions of iris had similar values. The eyes of recipients were also characterized by a local proliferation of pigment epithelium cells in the zones of retinal detachment. In these zones the index of labelled nuclei in the pigment epithelium equaled 11.0-31.3%.  相似文献   

14.
Diabetic retinopathy is the leading cause of visual dysfunction in working adults and is attributed to retinal vascular and neural cell damage. Recent studies have described elevated levels of membrane attack complex (MAC) and reduced levels of membrane associated complement regulators including CD55 and CD59 in the retina of diabetic retinopathy patients as well as in animal models of this disease. We have previously described the development of a soluble membrane-independent form of CD59 (sCD59) that when delivered via a gene therapy approach using an adeno-associated virus vector (AAV2/8-sCD59) to the eyes of mice, can block MAC deposition and choroidal neovascularization. Here, we examine AAV2/8-sCD59 mediated attenuation of MAC deposition and ensuing complement mediated damage to the retina of mice following streptozotocin (STZ) induced diabetes. We observed a 60% reduction in leakage of retinal blood vessels in diabetic eyes pre-injected with AAV2/8-sCD59 relative to negative control virus injected diabetic eyes. AAV2/8-sCD59 injected eyes also exhibited protection from non-perfusion of retinal blood vessels. In addition, a 200% reduction in retinal ganglion cell apoptosis and a 40% reduction in MAC deposition were documented in diabetic eyes pre-injected with AAV2/8-sCD59 relative to diabetic eyes pre-injected with the control virus. This is the first study characterizing a viral gene therapy intervention that targets MAC in a model of diabetic retinopathy. Use of AAV2/8-sCD59 warrants further exploration as a potential therapy for advanced stages of diabetic retinopathy.  相似文献   

15.
By means of highly sensitive radioimmunoassays, the levels of substance P (SP) and secretoneurin (SN) were detected in vitreous aspirates of patients with macular holes which served as controls, in patients with nonproliferative diabetic retinopathy (DR), active proliferative diabetic retinopathy (active PDR), inactive PDR, rhegmatogenous retinal detachment and proliferative vitreoretinopathy (PVR). Furthermore, SN-like immunoreactivities were characterized by reversed phase-HPLC. The concentration of SN was more than 20-fold higher in macular holes when compared with SP and reversed phase HPLC revealed evidence that the vitreous levels of SN represent authentic SN. SN was significantly decreased in patients with nonproliferative DR, active PDR and inactive PDR by more than 70% which seems to result from a reduced expression and/or secretion from the cilary epithelium and a reduced release from the retina both due to diabetes mellitus. By contrast SP was increased in rhegmatogenous retinal detachment most obviously due to an enhanced outflow of the peptide through retinal breaks. Despite their proangiogenic activities, SP and SN are unlikely to be involved in the pathogenesis of neovascularizations in DR because of their unchanged and reduced levels, respectively, but the low levels of both peptides may facilitate the regression of vasoproliferations following laser photocoagulation.  相似文献   

16.
Objective: Octreotide, a somatostatin analogue, has been shown to prevent angiogenesis in diverse in vitro models. We evaluated its effect on retinal neovascularization in vivo, using a neonatal rat retinopathy model. Methods: We used, on alternating days, hypoxia (10% O2) and hyperoxia (50% O2) during the first 14 days of neonatal rats, to induce retinal neovascularization. Half of the rats were injected subcutaneously with octreotide 0.7 μg/g BW twice daily. At day 18 the eyes were evaluated for the presence of epiretinal and vitreal hemorrhage, neovascularization and epiretinal proliferation. Octreotide pharmacokinetics and its effect on serum growth hormone (GH) and insulin-like growth factor I (IGF-I) were examined in 28 rats. Results: Serum octreotide levels were 667 μg/1 two hours after injection, 26.4 μg/1 after nine hours and 3.2 μg/1 after 14 hours. GH levels were decreased by 40% (p = 0.002) two hours after injection but thereafter returned to baseline. IGF-I levels were unchanged two hours after injection and were elevated by 26% 14 hours after injection (p = 0.02). Epiretinal membranes were highly associated with epiretinal hemorrhages (p < 0.001), while retinal neovascularization was notably associated with vitreal hemorrhages (p < 0.001). Conclusions: Twice-daily injections of octreotide failed to produce sustained decrease in serum GH, but produced rebound elevation of serum IGF-I. Accordingly, no statistically significant effect of injections on retinal pathology was noted. This finding, however, does not contradict our assumption that GH suppression may decrease the severity of retinopathy.  相似文献   

17.
We investigated the possible neuroprotectant and intraocular pressure (IOP) lowering effects of intravitreous injection of sodium hydrosulfide (NaSH) in a rodent model of experimental glaucoma. Glaucoma currently is treated by controlling IOP using medications and/or surgery. These methods are not entirely adequate for all patients. We divided 24 rats into three groups. For the control group, the right eye was treated with intravitreous saline. For the glaucoma group, ocular hypertension was induced by photocoagulating three episcleral veins and the limbal plexus of the right eye using an argon laser, then saline was injected into the vitreous of these eyes during the third week. For the NaSH group, rats were treated with intravenous NaSH 3 weeks after photocoagulation. IOP was measured each week during the 6 week experimental period. Coagulating the episcleral veins rapidly increased the IOP of rat eyes. Intravitreous injection of NaSH significantly reduced IOP. Intravitreous NaSH prevented degeneration of the retina and decreased the number of apoptotic cells. Intravitreous NaSH appeared to reduce IOP and to prevent IOP induced retinopathy in rats.  相似文献   

18.
Retinal detachment remains one of the most frequent causes of visual impairment in humans, even after ophthalmoscopically successful retinal reattachment. This study was aimed at monitoring (ultra-) structural alterations of retinae of rabbits after experimental detachment. A surgical procedure was used to produce local retinal detachments in rabbit eyes similar to the typical lesions in human patients. At various periods after detachment, the detached retinal area as well as neighbouring attached regions were studied by light and electron microscopy. In addition to the well-known degeneration of photoreceptor cells in the detached retina, the following progressive alterations were observed, (i) in both the detached and the attached regions, an incomplete but severe loss of ganglion cell axons occurs; (ii) there is considerable ganglion cell death, particularly in the detached area; (iii) even in the attached retina distant from the detachment, small adherent groups of photoreceptor cells degenerate; (iv) these photoreceptor cells degenerate in an atypical sequence, with severely destructed somata and inner segments but well-maintained outer segments; and (v) the severe loss of retinal neurons is not accompanied by any significant loss of Müller (glial) cells. It is noteworthy that the described progressive (and probably irreparable) retinal destructions occur also in the attached retina, and may account for visual impairment in strikingly large areas of the visual field, even after retinal reattachment.  相似文献   

19.
Inflammation affects the formation and the progression of various vitreoretinal diseases. We performed a comprehensive analysis of inflammatory immune mediators in the vitreous fluids from total of 345 patients with diabetic macular edema (DME, n = 92), proliferative diabetic retinopathy (PDR, n = 147), branch retinal vein occlusion (BRVO, n = 30), central retinal vein occlusion (CRVO, n = 13) and rhegmatogenous retinal detachment (RRD, n = 63). As a control, we selected a total of 83 patients with either idiopathic macular hole (MH) or idiopathic epiretinal membrane (ERM) that were free of major pathogenic intraocular changes, such as ischemic retina and proliferative membranes. The concentrations of 20 soluble factors (nine cytokines, six chemokines, and five growth factors) were measured simultaneously by multiplex bead analysis system. Out of 20 soluble factors, three factors: interleukin-6 (IL-6), interleukin-8 (IL-8), and monocyte chemoattractant protein-1 (MCP-1) were significantly elevated in all groups of vitreoretinal diseases (DME, PDR, BRVO, CRVO, and RRD) compared with control group. According to the correlation analysis in the individual patient''s level, these three factors that were simultaneously increased, did not show any independent upregulation in all the examined diseases. Vascular endothelial growth factor (VEGF) was significantly elevated in patients with PDR and CRVO. In PDR patients, the elevation of VEGF was significantly correlated with the three factors: IL-6, IL-8, and MCP-1, while no significant correlation was observed in CRVO patients. In conclusion, multiplex bead system enabled a comprehensive soluble factor analysis in vitreous fluid derived from variety of patients. Major three factors: IL-6, IL-8, and MCP-1 were strongly correlated with each other indicating a common pathway involved in inflammation process in vitreoretinal diseases.  相似文献   

20.
摘要 目的:探讨玻璃体腔注射康柏西普对于严重后巩膜裂伤患者玻璃体切除术后增生性玻璃体视网膜病变发生的预防效果。方法:选取从2018年9月至2020年9月我院收治的40例(40眼)严重后巩膜裂伤患者进行研究,随机分为对照组20眼(行常规巩膜裂伤缝合术及经睫状体平坦部玻璃体切除术)和观察组20眼(行巩膜裂伤缝合术及经睫状体平坦部玻璃体切除术的同时联合玻璃体腔注射康柏西普治疗)。比较两组患者术前及术后的视力、眼压,以及术后增生性玻璃体视网膜病变的发生率、视网膜再脱离的发生率。结果:对照组及观察组术后的最佳矫正视力较术前均提高、术后眼压均正常,观察组术后的增生性玻璃体视网膜病变发生率(15.0 %)明显低于对照组(45.0 %, P<0.05),观察组术后视网膜脱离复发率(5.0 %)低于对照组(30.0 %, P>0.05)。结论:严重后巩膜裂伤患者玻璃体切除术联合玻璃体注射康柏西普治疗能够有效降低增生性玻璃体视网膜病变的发生率和术后视网膜脱离的复发率,还可以改善患者的视力预后。  相似文献   

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