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1.
The aim of this study was to elucidate the effect of bone morphogenetic protein-7 (BMP-7) on liver fibrosis induced by carbon tetrachloride (CCl4) in vivo and on the hepatic stellate cells (HSC) activation in vitro. In vivo, thirty male ICR mice were randomly allocated to three groups, the control group (n = 6), the CCl4 group (n = 18) and the BMP-7+CCl4 group (n = 6). The model of liver fibrosis was induced by intraperitoneal injection with CCl4 three times per week lasting for 12 weeks in CCl4 group and the BMP-7+CCl4 group. After 8 weeks injection with CCl4, mice were intraperitoneal injected with human recombinant BMP-7 in BMP-7+CCl4 group. Meanwhile, mice in the CCl4 group were only intraperitoneal injection with equal amount of saline. The degree of liver fibrosis was assessed by HE and Masson’s staining. PCR and western blot were used to detect mRNA and protein levels. In BMP-7+CCl4 group, serum levels of alanine aminotransferase (ALT) and aminotransferase (AST) were decreased and serum albumin (Alb) was increased. Meanwhile, the expressions of transforming growth factor-β1 (TGF-β1) and α-smooth muscle actin (α-SMA) were down-regulated by BMP-7 intervention as compared to the CCl4 group (P < 0.05). Furthermore, BMP-7 also suppressed the expression of epidermal growth factor receptor (EGFR) and phosphorylated-epidermal growth factor receptor (pEGFR). HE and Masson stain showed that liver damage was alleviated in BMP-7+CCl4 group. In vitro study, expression of EGFR, TGF-β1 and α-SMA were down regulated by BMP-7 dose-dependently, indicating it might effect on suppression of HSC activation. Therefore, our data indicate BMP-7 was capable of inhibiting liver fibrosis and suppressing HSCs activation, and these effects might rely on its crosstalk with EGFR and TGF-β1. We suggest that BMP-7 may be a potential reagentfor the prevention and treatment of liver fibrosis.  相似文献   

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Both platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGF-beta) are known to be pivotal cytokines in liver fibrosis development. The aim of our current study was to elucidate the effects of dual inhibition of PDGF and TGF-beta by combination of the clinically used imatinib mesylate (STI-571) and perindopril (an ACE-inhibitor; ACE-I), respectively, on ongoing liver fibrosis development in rats. The effects of STI-571 and ACE-I at clinically comparable low doses were examined in a rat model of CCl4-induced liver fibrogenesis. Treatment with both STI-571 and ACE-I inhibited liver fibrogenesis and suppressed activation of hepatic stellate cells (HSCs). Administration of both agents exerted a more potent inhibitory effect than administration of either single agent. Our in vitro study demonstrated that STI-571 and ACE-I suppressed PDGF receptor (PDGFR) phosphorylation and TGF-beta expression in activated HSCs, respectively. Dual suppression of PDGF and TGF-beta with a combination of clinically comparable low doses of STI-571 and ACE-I exerted a significant inhibitory effect on ongoing liver fibrosis development. Since both agents are widely used in clinical practice, this combination therapy may provide a new strategy against liver fibrosis in the future.  相似文献   

4.
Hepatic stellate cells (HSCs) interact with fibrillar collagen through the discoidin domain receptor 2 (DDR2) in acute hepatic injury, generating increased fibrosis. However, the contribution of DDR2 signaling to chronic liver fibrosis in vivo is unclear, despite its relevance to chronic human liver disease. We administered carbon tetrachloride (CCl(4)) to DDR2(+/+) and DDR2(-/-) mice twice weekly, and liver tissues and isolated HSCs were analyzed. In contrast to changes seen in acute injury, after chronic CCl(4) administration, DDR2(-/-) livers had increased collagen deposition, gelatinolytic activity, and HSC density. Increased basal gene expression of osteopontin, transforming growth factor-β1, monocyte chemoattractant protein-1, and IL-10 and reduced basal gene expression of matrix metalloproteinase-2, matrix metalloproteinase-13, and collagen type I in quiescent DDR2(-/-) HSCs were amplified further after chronic CCl(4). In concordance, DDR2(-/-) HSCs isolated from chronically injured livers had enhanced in vitro migration and proliferation, but less extracellular matrix degradative activity. Macrophages from chronic CCl(4)-treated DDR2(-/-) livers showed stronger chemoattractive activity toward DDR2(-/-) HSCs than DDR2(+/+) macrophages, increased extracellular matrix degradation, and higher cytokine mRNA expression. In conclusion, loss of DDR2 promotes chronic liver fibrosis after CCl(4) injury. The fibrogenic sinusoidal milieu generated in chronic DDR2(-/-) livers recruits more HSCs to injured regions, which enhances fibrosis. Together, these findings suggest that DDR2 normally orchestrates gene programs and paracrine interactions between HSCs and macrophages that together attenuate chronic hepatic fibrosis.  相似文献   

5.
目的探讨神经生长因子低亲合力受体(P75)在肝纤维化患者和大鼠肝星状细胞(HSCs)的分布及作用机制。方法对四氯化碳(CCL)法制备的肝纤维化大鼠肝组织及肝穿刺获取的肝纤维化患者肝组织,常规石蜡包埋;大鼠离体培养的活化HSCs离心涂片,行免疫组织化学染色,确定P75的表达分布。结果P75在大鼠离体培养的活化HSCs膜,免疫组织化学染色呈阳性,在肝纤维化患者HSCs膜和肝细胞膜,免疫组织化学染色呈阳性,在肝纤维化大鼠HSCs膜和肝细胞膜,免疫组织化学染色呈阳性,在健康人和正常对照大鼠HSCs膜,免疫组织化学染色呈阴性,表明人和大鼠活化的HSCs膜表达P75。结论P75为肝纤维化的治疗提供了新的靶点。  相似文献   

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 目的:探讨四氯化碳诱导肝纤维化早期大鼠肝窦毛细血管化的形成过程。方法:清洁级雄性SD大鼠采用随机数字表法随机分为2组:正常对照组(N组,6只)和肝纤维化模型组(M组,32只)。M组大鼠腹腔注射50%四氯化碳蓖麻油混合液, N组大鼠腹腔注射生理盐水,剂量为2 mL/kg,每周2次,共4周。分别于造模第3天、1周、2周和4周处死大鼠,HE染色和Masson染色观察肝脏组织炎症及纤维化的改变,透射电镜观察肝窦内皮细胞(LSECs)窗孔与基底膜(BM)的改变,免疫组织化学检测LSECs表面标志物CD31及基底膜成分IV型胶原(Col IV)和层黏连蛋白(LN)的改变。结果:HE及Masson染色显示四氯化碳造模4周早期肝纤维化已形成。肝组织透射电镜显示四氯化碳造模第3天后开始出现LSECs窗孔直径变小及数目减少,随着造模时间的延长,LSECs失窗孔现象逐步严重,至第4周时局部内皮下可见连续的基底膜。免疫组化染色显示LSECs表面标志物CD31表达随着LSECs窗孔数目的减少而逐渐增强;基底膜成分Col IV于造模第2周时表达开始显著增强并随着造模时间延长表达逐渐增强,LN于造模第4周时表达开始显著增强。结论:肝纤维化早期大鼠局部肝组织可见典型的肝窦毛细血管化形成;肝窦壁内LN沉积是肝窦毛细血管化时形成连续基底膜的关键因素。  相似文献   

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Mineralocorticoid receptor (MR) antagonist spironolactone (SPL) is an effective agent for prevention of cardiovascular injury. However, whether and how SPL ameliorates hepatic fibrosis in rats is unknown. Pig serum (PS) (0.5 mL, twice a week, ip) or vehicle-administered rats for 12 weeks were used as rats with hepatic fibrosis or control rats, respectively. Rats given PS were treated with SPL (50 mg/kg/day, sc) for 12 weeks. Hepatic fibrosis, using picro-sirius red staining and determination of hydroxyproline content, immunohistochemistries of alpha-smooth muscle actin (alpha-SMA)-positive hepatic stellate cells (HSCs), Na/H exchange isoform-1 (NHE-1) protein, CYP11B2 aldosterone synthase protein for liver tissues, and plasma aldosterone concentrations were compared among the 3 groups of rats. Rats given PS alone exhibited hepatic fibrosis as well as increases in the number of the alpha-SMA-positive HSCs and NHE-1 protein expression in HSCs and hepatocytes, all of which were suppressed by SPL. Rats given PS alone revealed increased CYP11B2 protein expression in HSCs and hepatocytes, which was not inhibited by SPL. Plasma aldosterone concentrations were significantly greater in rats given PS and SPL than in control rats and rats given PS alone, although they were not different between control rats and rats given PS alone. PS-induced hepatic fibrosis together with HSC activation and NHE-1 protein expression occurs via MRs, and SPL ameliorates hepatic fibrosis presumably via the inhibition of HSC activation and NHE-1 protein expression in PS-induced liver injuries. The aldosterone produced in the injured liver contributes to the PS-induced hepatic fibrosis.  相似文献   

9.
Tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta 1 (TGF-beta 1) have a number of in vitro functions that could be important in vivo in acute liver injury and repair. Therefore, we investigated these two cytokines in acute liver damage. Northern blots of RNA isolated from rats sacrificed at various time intervals after a single oral dose of CCl4 revealed that TNF-alpha mRNA levels were elevated within 6 hr of CCl4 administration and returned to control values by 24-32 hr. In contrast, TGF-beta 1 mRNA levels started to rise significantly at 24 hr, peaked at 48 hr, and approached baseline levels by 72 hr. Identical changes in TNF-alpha and TGF-beta 1 mRNA levels were also seen with D-galactosamine-induced hepatotoxicity. Immunohistochemical analysis using a TGF-beta 1 antibody demonstrated increased hepatic staining in CCl4-treated rats, at times corresponding to the increases in TGF-beta 1 gene expression. Therefore, there is a differential expression of these cytokines in acute CCl4 and galactosamine hepatotoxicity with an early rise in TNF-alpha, suggesting that this cytokine may affect inflammation and cell toxicity, while TGF-beta 1 peaks later, when it may regulate hepatocyte proliferation and extracellular matrix repair.  相似文献   

10.
BACKGROUND/AIM: Angiotensin converting enzyme (ACE) and angiotensin II (AT-II) have been suggested to play an important role in liver fibrogenesis. There is a significant relationship between inheritance of hightened expression of transforming growth factor beta1 (TGF-beta1) and AT-II and the development of progressive hepatic fibrosis. The purpose of this study was to investigate the effects of captopril, an ACE inhibitor and candesartan cilexetil, an AT-II type 1 receptor (AT1-R) blocker, on liver fibrosis induced in rats by carbon tetrachloride (CCl4) administration. METHODS: rats were divided into 4 experimental groups: The first group was given CCl4 alone; the second was given both CCl4 and captopril (100 mg x kg(-1) x day(-1)); the third was given both CCl4 and candesartan cilexetil (8 mg x kg(-1) x day(-1)); fourth group was given 0.9% NaCl only. Seven weeks after initiating the treatment, indices of fibrosis were assessed. RESULTS: Candesartan cilexetil treatment significantly reduced the fibrosis development. These inhibitory effects were not observed in the captopril-treated group. The mean fibrosis score was significantly lower in the CCl4/candesartan group compared with the group applied to CCl4 alone and the group applied to CCl4/captopril. Similarly, the number of alpha-smooth muscle actin positive cells was markedly suppressed by candesartan treatment. CONCLUSIONS: The results suggest that AT-II plays a pivotal role in hepatic fibrogenesis and candesartan significantly attenuates the progression of liver fibrosis. This drug may provide an effective new strategy for prevention of liver fibrosis. Its effectiveness should be investigated in chronic liver disease associated with progressive fibrosis.  相似文献   

11.
Using a developed rat model of hepatic necrosis and subsequent fibrosis induced by a high-dose intraperitoneal injection of dimethylnitrosamine (DMN), we studied iron deposition and expression of transforming growth factor-beta(1) (TGF-beta(1)) during the development of persistent liver fibrosis. Rats were sacrificed at several timepoints from 6 h to 10 months post-injection and the livers were examined for iron content and distribution, and for expression of alpha-smooth muscle actin, ED-1, TGF-beta(1), and collagen (alpha(2))I. Morphologic evidence of acute submassive hemorrhagic necrosis peaked at 36 h; on day 3 the residual parenchyma contained activated hepatic stellate cells (HSCs) and necrotic areas contained numerous macrophages; and on day 5, necrotic tissues and erythrocytes had been phagocytosed and macrophages contained abundant iron deposits. From days 7 to 10, iron-laden macrophages and activated HSCs (myofibroblasts) populated the fibrous septa in parallel. From week 2 to month 10, closely arranged macrophages and myofibroblasts were found in central-to-central bridging fibrotic tissue. TGF-beta(1) was strongly detected in both macrophages and HSCs during development of liver fibrosis. Our data suggest that increased iron deposition may be involved in the initiation and perpetuation of rat liver fibrosis. Iron-laden macrophages may influence HSCs through the action of TGF-beta(1) in DMN-induced liver fibrosis.  相似文献   

12.
目的: 研究金属硫蛋白(MT)在体内及体外与基质金属蛋白酶-2(MMP-2)表达、活性之间的相关性。方法: 昆明种雄性成年小鼠50只,其中实验鼠 40只,对照鼠10只,用CCl4诱导小鼠肝纤维化模型。向肝星状细胞(HSCs)条件培养基(含有MMP-2)中加不同浓度MT,使之与MMP-2酶学共浴,检测MMP-2活性。制作小鼠肝组织芯片,天狼猩红染色判断肝纤维化程度。免疫组化法测肝组织MMP-2、MT蛋白表达,酶图法测鼠肝组织匀浆和培养基中MMP-2活性。结果: ①模型组小鼠肝组织MMP-2和MT蛋白表达水平均随纤维化进展而呈波浪式交替升高,但二者时相变化相反。 ②模型组小鼠肝组织MMP-2活性随实验时间的增加而逐渐升高,亦有波动。除个别时点外,酶活性与MT表达呈负相关。③肝星状细胞条件培养基与不同浓度的MT直接作用后,MMP-2活性随MT浓度增加活性逐渐降低(P<0.01)。结论: 在小鼠肝纤维化发生发展过程中,肝组织MT蛋白和MMP-2蛋白表达均有上升趋势,二者间可能存在相互作用;MT蛋白和MMP-2活性呈负相关,前者对后者可能起抑制作用。  相似文献   

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Chemokines, such as CXCL10, promote hepatic inflammation in chronic or acute liver injury through recruitment of leukocytes to the liver parenchyma. The CXCL10 receptor CXCR3, which is expressed on a subset of leukocytes, plays an important part in Th1-dependent inflammatory responses. Here, we investigated the role of CXCL10 in chemically induced liver fibrosis. We used carbon tetrachloride (CCl(4)) to trigger chronic liver damage in wildtype C57BL/6 and CXCL10-deficient mice. Fibrosis severity was assessed by Sirius Red staining and intrahepatic leukocyte subsets were investigated by immunohistochemistry. We have further analyzed hepatic stellate cell (HSC) distribution and activation and investigated the effect of CXCL10 on HSC motility and proliferation. In order to demonstrate a possible therapeutic intervention strategy, we have examined the anti-fibrotic potential of a neutralizing anti-CXCL10 antibody. Upon CCl(4) administration, CXCL10-deficient mice showed massively reduced liver fibrosis, when compared to wildtype mice. CXCL10-deficient mice had less B- and T lymphocyte and dendritic cell infiltrations within the liver and the number and activity of HSCs was reduced. In contrast, natural killer (NK) cells were more abundant in CXCL10-deficient mice and granzyme B expression was increased in areas with high numbers of NK cells. Further detailed analysis revealed that HSCs express CXCR3, respond to CXCL10 and secrete CXCL10 when stimulated with IFNγ. Blockade of CXCL10 with a neutralizing antibody exhibited a significant anti-fibrotic effect. Our data suggest that CXCL10 is a pro-fibrotic factor, which participates in a crosstalk between hepatocytes, HSCs and immune cells. NK cells seem to play an important role in controlling HSC activity and fibrosis. CXCL10 blockade may constitute a possible therapeutic intervention for hepatic fibrosis.  相似文献   

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解耦联蛋白2对大鼠肝纤维化形成中星形细胞活化的影响   总被引:1,自引:1,他引:0  
目的探讨解耦联蛋白2(UCP2)在肝纤维化形成过程中的作用及其发生机制。方法体内实验采用四氯化碳(CCl4)诱导肝纤维化模型,取肝脏观察病理变化,用Western blotting、免疫组织化学和Real-time PCR等方法检测UCP2和p38丝裂素活化蛋白激酶(p38MAPK)的表达水平;体外实验采用UCP2特异性抑制剂京尼平和CCl4刺激星形细胞,检测UCP2和p38MAPK相关蛋白的表达情况。结果与正常组相比,模型组大鼠肝脏α-平滑肌肌动蛋白(α-SMA)和UCP2表达增高(P0.05,n=10);加入CCl4刺激细胞后,星形细胞α-SMA表达增加,p38MAPK及其磷酸化水平增高(P0.05,n=6);而在加入京尼平后,α-SMA表达增加,p38 MAPK及其磷酸化水平明显降低(P0.05,n=6)。结论 UCP2参与了肝纤维化的发生,可能促进了星形细胞的活化及增殖过程。  相似文献   

15.
Carbon tetrachloride (CCl(4)) was used to induce liver fibrosis in the rat. Using this model, we have identified changes in serum and urinary clinical chemistry parameters, and characterized histopathological lesions in the liver. Two experiments were conducted. In Experiment 1, rats were dosed at six levels of CCl(4) (0.06-0.36 ml/kg) twice weekly for 6 weeks, followed by a 6-week non-dosing recovery period (week 12). Livers were removed for histology at 6 and 12 weeks and serum parameters analysed. In Experiment 2, rats were given seven dose levels of CCl(4) (0.4-1.0 ml/kg) twice weekly for 6 weeks, followed by a 6-week recovery period (week 12); urine samples were analysed at 3, 6, 9 and 12 weeks using one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Liver fibrosis was evident at 6 weeks in Experiments 1 and 2, and the activity of serum enzymes (including alanine aminotransferase, aspartate aminotransferase and glutamate dehydrogenase) was increased. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis (Experiment 2) revealed a protein band at 18.4 kDa in urine from rats treated with CCl(4), not present in control urine, which was identified as copper/zinc superoxide dismutase (Cu/Zn SOD). Western blotting revealed that SOD was increased in urine from rats treated with CCl(4) at 3 and 6 weeks, but not at 9 and 12 weeks. We conclude that Cu/Zn SOD is a urinary marker of hepatic necrosis, but not hepatic fibrosis.  相似文献   

16.
Recent functional research studies suggest an anti-fibrotic role for natural killer (NK) cells coupled with a profibrotic role for CD8 cells. However, the morphological cellular interplay between the different cell types is less clear. To investigate lymphocyte/hepatic stellate cell (HSC) interactions, hepatic fibrosis was induced by administering carbon tetrachloride (CCl4) intraperitoneally (i.p.) for 4 weeks in C57Bl/6 mice. Animals were killed at 0, 1, 2, 3 and 4 weeks. Liver sections were stained for Sirius red. Confocal microscopy was used to evaluate alpha smooth-muscle actin (alphaSMA) and lymphocyte subsets in liver sections. At weeks 0 and 4, liver protein extracts were assessed for alphaSMA by Western blotting and isolated liver lymphocytes as well as HSC were analysed by fluorescence activated cell sorter (FACS). Similar to the results obtained from classical Sirius red staining and alphaSMA blotting, analysis of liver sections by confocal microscopy revealed a marked and continuous accumulation of alphaSMA staining along sequential experimental check-points after administering CCl4. Although the number of all liver lymphocyte subsets increased following fibrosis induction, FACS analysis revealed an increase in the distribution of liver CD8 subsets and a decrease of CD4 T cells. Confocal microscopy showed a significant early appearance of CD8 and NK cells, and to a lesser extent CD4 T cells, appearing only from week 2. Lymphocytes were seen in proximity only to HSC, mainly in the periportal area and along fibrotic septa, suggesting a direct interaction. Notably, lymphocyte subsets were undetectable in naive liver sections. Freshly isolated HCS show high expression of major histocompatibility complex (MHC) class II and CD11c. In the animal model of hepatic fibrosis, lymphocytes infiltrate into the liver parenchyma and it is thought that they attach directly to activated HSC. Because HSCs express CD11c/class II molecules, interactions involving them might reflect that HSCs have an antigen-presenting capacity.  相似文献   

17.
背景:混合物脑肽是从动物脑中提取的多肽混合物,含有神经生长因子成分。近年研究发现,神经生长因子与肝损伤密切相关。 目的:使用自拟混合物脑肽观察对大鼠肝纤维化的影响。 方法:利用四氯化碳诱导形成SD大鼠肝纤维化模型。将大鼠随机分成纤维化模型组、脑肽干预组和对照组。4,8周采集标本。通过活体解剖取门静脉血清采用全自动生化分析仪检测肝功能丙氨酸氨基转移酶、天冬氨酸氨基转移酶、总胆红素、白蛋白;采用放射免疫法检测血清肝纤维化指标透明质酸、层粘连蛋白、Ⅲ型前胶原;常规苏木精-伊红和网状纤维染色检测肝组织标本。 结果与结论:大鼠肝纤维化模型成功建立。脑肽干预组纤维化程度较纤维化模型组显著减轻,但肝组织炎症和肝细胞脂肪变性反而较纤维化模型组更显著。初步判断脑肽能够阻断四氯化碳诱导的肝纤维化,可能与神经生长因子有关。  相似文献   

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目的 探讨转化生长因子TGF-β1/Smad信号通路在实验性肝纤维化发生中的作用.方法 50只健康雄性SD大鼠分为2组:正常组和模型组,模型组大鼠利用40% CCl4油剂诱导形成肝纤维化模型,于6周及9周观测肝标本的病理,免疫组化法检测肝组织TGF-β1/Smad蛋白表达.结果 ①肝组织病理:与正常组比较,模型组大鼠肝组织都有不同程度的炎症和纤维化产生.模型组纤维化程度较正常对照组明显,差异有统计学意义(P<0.05);②TGF-β1/Smad基因蛋白:免疫组织化学检测显示,与正常对照组相比,模型组大鼠肝脏中TGF-β1、转化生长因子βⅠ型受体(TβR-Ⅰ)、Smad2/3、Smad7蛋白表达均显著增强(P<0.01),模型组大鼠肝脏TGF-β1、TβR-Ⅰ、Smad2/3和Smad7之间存在正相关关系(P <0.05或0.01);模型组大鼠肝脏纤维化分级与TGF-β1、TβR-Ⅰ、Smad2/3和Smad7之间存在正相关关系(P<0.05或0.01).结论 肝组织TGF-β1/Smad蛋白表达水平与肝纤维化程度相关,TGF-β1/Smad信号的增强可能促进了肝纤维化的进展.  相似文献   

20.
结缔组织生长因子在人及大鼠肝纤维化组织中表达增强   总被引:4,自引:0,他引:4  
目的观察结缔组织生长因子(CTGF)在人及大鼠肝纤维化组织中的表达。方法雄性SD大鼠32只,皮下注射CCl4后1、4、8周收集肝组织标本;44例人肝组织,其中包括12例正常肝组织、32例慢性病毒性肝炎和肝硬化组织。用免疫组化方法检测CTGF的表达及分布。结果CTGF主要表达于大鼠肝星状细胞及肝细胞胞质中。注射CCl4后,大鼠肝组织中CTGF呈时间依赖性表达增强(P<0.01或P<0.05)。CTGF在人肝纤维化组织中的表达与大鼠相类似,表达水平显著高于正常人(P<0.01)。结论CTGF作为一种促纤维化因子,其过表达可促进肝星状细胞的增殖活化,促进细胞外基质的形成,从而促进肝纤维化的发生、发展。  相似文献   

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