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1.
目的建立诱发性2型糖尿病小鼠模型,并将其与自发性2型糖尿病小鼠db/db进行比较分析。客观评价两种2型糖尿病小鼠模型,为糖尿病研究中动物模型的选择与实际应用提供实验依据。方法高脂饲料喂养C57BL/6J小鼠4周,腹腔连续3次注射STZ,建立诱发性2型糖尿病小鼠模型。感染后4周,大体肉眼观察小鼠的肝脏、肾脏,测定糖耐量,血清生化指标及血清细胞因子IL-2、IL-4、IL-6、IFN-γ、TNF-α、IL-17、IL-10表达量,将其与同龄的自发性2型糖尿病小鼠db/db进行比较分析。结果肉眼观察发现,两组模型小鼠的肝脏、肾脏与对照组均具有明显差异。糖耐量分析中,两组模型小鼠与对照组小鼠各时间点的血糖值均具有统计学差异(P〈0.05),耐糖功能低下,两组模型小鼠间血糖值无统计学差异。血液生化指标中,与对照组小鼠相比,两组模型小鼠GLU、CHOL、LDLC明显升高(P〈0.05);两组模型小鼠相互比较,诱发性2型糖尿病小鼠血脂水平较高(P〈0.05)。免疫指标比较显示:除IL-2外,两组模型小鼠血清中细胞因子水平均较对照组小鼠明显升高(P〈0.05),而db/db小鼠血清中细胞因子表达较诱发性糖尿病小鼠高,其中IL-6、IFN-γ、TNF-α具有显著性差异(P〈0.05)。结论两组2型糖尿病模型小鼠均在一定程度上模拟了人类糖尿病患者症状,但由于糖尿病产生的原因不同而存在着一定的差异,研究者可根据实际需要参照相关数据进行选择。  相似文献   

2.
目的检测瘦素受体缺陷的Lepr~(db/db)小鼠体内肝、肾中硫辛酸合成酶(LIAS)的表达。方法分别选取10周龄Lepr~(db/+)与Lepr~(db/db)雄性小鼠各8只,禁食8 h后,测量两组小鼠体重及空腹血糖(FPG);用乙醚麻醉动物,经腹主动脉采血,处死动物,取肝、肾并称重。取肝右叶和左肾经4%多聚甲醛固定,进行肝、肾组织病理学检查。分离血清,用试剂盒检测血清中CHO、TG、HDL、LDL含量。应用线粒体分离试剂盒分离肝、肾组织线粒体,提取总蛋白,采用western blot方法检测LIAS蛋白的表达。结果组织病理观察,发现Lepr~(db/+)小鼠肝肾结构完整,而Lepr~(db/db)小鼠肝细胞出现脂肪变性,肾小球肥大,基底膜增厚,系膜区增宽;与Lepr~(db/+)小鼠比较,Lepr~(db/db)小鼠体重、GLU、CHO、TG、LDL及AST明显增高,差异有显著性(P0.05);与Lepr~(db/+)小鼠比较,Lepr~(db/db)小鼠肝肾线粒体内LIAS蛋白表达量均增高,差异有显著性(P0.05)。结论瘦素受体缺陷的Lepr~(db/db)小鼠存在糖脂代谢紊乱、肝肾细胞损伤、肝肾组织线粒体LIAS蛋白的表达增高。  相似文献   

3.
目的建立一种高效的应用Taq Man探针荧光定量PCR技术对Lepr~(db/+)小鼠子代基因分型的方法。方法提取228例Lepr~(db/+)小鼠子代鼠尾DNA,针对Lepr基因的突变位点(rs1801133)设计1对PCR引物和2条Taq Man探针。设定条件进行实时荧光PCR扩增,用SDS软件对SNP位点进行分型。通过2月龄动物的肥胖表现型验证并进行Hardy-Weinberg平衡检验。结果用建立的Taq Man探针荧光定量PCR方法对228份样本进行检测,其中GG基因型64份,基因型频率为0.1929;GT基因型123份,基因型频率为0.5395;TT基因型41份基因型频率为0.2807。Taq Man探针荧光定量PCR方法分型结果与通过肥胖表现型分型结果比较,灵敏度为97.56%,特异度为99.47%。结论应用Taq Man探针荧光定量PCR技术可实现对Lepr~(db/+)小鼠子代基因位点的早期分型检测,方法简便,高效。  相似文献   

4.
非酒精性脂肪性肝病(nonalcoholic fatty liver disease, NAFLD)是指肝中储存过多的脂肪,与肥胖、胰岛素抵抗、2型糖尿病(type-2 diabetes mellitus, T2DM)、血脂异常等代谢综合征密切相关。肝纤维化是NAFLD进一步发展为肝细胞癌(hepatocellular carcinoma, HCC)的关键过程,减少肝内的脂肪积累,从而延缓或阻止NAFLD向纤维化的进展是治疗的关键。树豆酮酸A(cajanonic acid A, CAA)在2型糖尿病中能够有效改善胰岛素抵抗,发挥降糖减脂作用。本研究旨在探究CAA对NAFLD肝损伤的保护作用。通过采用db/db自发性NAFLD小鼠模型,将db/db小鼠分为NAFLD组和CAA给药组,CAA组予50 mg/(kg·d)灌胃给药,同期C57BL小鼠作为正常对照组(NC组),每组6只。小鼠生化指标检测和组织病理染色发现,CAA干预可有效缓解db/db小鼠的糖脂代谢紊乱、肝功能损伤(P<0.05)及肝脂肪变性和减少脂质沉积(P<0.05)。ELISA法结果显示,经过CAA治疗后肝组织...  相似文献   

5.
C-Fos在db/db自发性糖尿病小鼠颌下腺的表达   总被引:4,自引:0,他引:4  
目的观察转基因糖尿病小鼠下颌下腺形态学改变与原癌基因C-fos蛋白表达的关系,为糖尿病的临床及基础研究提供依据。方法引进日本C57BL/ksj-db/ m表型正常隐性基因小鼠,其近亲交配所得纯合子后代,即为db/db(单基因遗传自然发病型)糖尿病小鼠。取3、4、6、8、10月龄db/db糖尿病小鼠及相应月龄的db/ m正常小鼠下颌下腺,行HE染色及SP免疫组化染色后进行图象分析,统计各组下颌下腺C-fos阳性表达的细胞数,观察其形态学改变。结果糖尿病小鼠下颌下腺腺泡萎缩,细胞缩小,形态不规则,排列不整齐。各月龄糖尿病小鼠颌下腺C-Fos阳性细胞明显低于相应对照组(P<0.01),且逐渐减少,呈下降趋势。结论db/db糖尿病状态下颌下腺细胞表达C-Fos蛋白明显降低,c-fos低表达可能与下颌下腺实质细胞的增殖减弱性形态学变化密切相关。  相似文献   

6.
目的:探讨烟酰胺核糖(NR)对2型糖尿病小鼠心肌病的治疗作用及其机制。方法:2型糖尿病模型db/db鼠和及其严格对照小鼠db/+小鼠,将小鼠分为Con (db/+)组,DM (db/db)组,DM+NR组。采用超声测小鼠心脏功能,western-blot及免疫组化测SIRT1表达含量,DHE染色、MDA含量和MnSOD活性检测反映氧化应激水平。结果:与对照组相比,db/db小鼠心脏功能显著下降(LVEF:42.3±7.2vs 73.7±10.2, P0.01;LVFS:22.1±4.2vs 42.7±6.9, P0.01),SIRT1表达量显著下调(P0.01)。NR喂养提高SIRT1表达量(P0.01),并有效改善db/db小鼠心脏功能(LVEF:53.1±8.1vs 42.3±7.2, P0.01;LVFS:33.4±6.9vs 22.1±4.2, P0.01)。同时,NR喂养显著降低了db/db小鼠心肌组织的凋亡水平和氧化应激水平(P0.05)。结论:NR有效改善了db/db小鼠的心功能障碍,降低了db/db小鼠的心肌凋亡水平和氧化应激水平,这些作用的发挥可能与NR增加SIRT1的表达量有关。  相似文献   

7.
目的探索两色金鸡菊中黄酮类成分马里苷、黄诺玛苷对db/db小鼠肠道菌群的影响。方法将db/m小鼠作为正常对照组,db/db小鼠分为db/db模型组、db/db+恩格列净(db/db+Empagliflozin)组、db/db+马里苷(db/db+Marein)组、db/db+黄诺玛苷(db/db+Flavanomarein)组,每组8只。采用实时荧光定量PCR(RT-qPCR)的方法检测小鼠粪样中Bacteroides ovatus、Ruminococcus gnavus的变化,并运用Pearson检验分析Bacteroides ovatus、Ruminococcus gnavus的变化与2型糖尿病相关表型的相关性。结果 (1)干预12周后与db/m组相比,db/db组小鼠粪样中Bacteroides ovatus水平显著降低(P0.010);恩格列净(P0.001)、马里苷(P0.050)、黄诺玛苷(P0.001)干预后能显著升高其含量,差异具有统计学意义。(2)与db/m组相比,db/db组小鼠粪样中Ruminococcus gnavus水平显著升高(P0.050);恩格列净(P0.050)、马里苷(P0.050)干预后能显著降低其含量,差异具有统计学意义。(3)Bacteroides ovatus水平与空腹血糖(FBG)、三酰甘油(TG)呈负相关(r=-0.420,P=0.021;r=-0.474,P=0.008);Ruminococcus gnavus水平与FBG、TG呈正相关(r=0.397,P=0.030;r=0.404,P=0.027)。结论马里苷、黄诺玛苷可以调节小鼠肠道菌群的变化,这可能是其抗糖尿病的重要机制。  相似文献   

8.
Levin提出饮食诱导肥胖(DIO)与饮食诱导肥胖抵抗(DIO-R)的概念后,其发生机制受到了广泛关注。现代研究认为脂肪组织除了能调节能量代谢外,还可以分泌多种细胞因子,如瘦素、脂联素、肿瘤坏死因子-α(TNF-α)和抵抗素等。在已发现的脂肪细胞因子中,瘦素、TNF-α和脂联素等与肥胖的发生密切关联。DIO大鼠血清瘦素水平比DIO-R大鼠高,DIO大鼠瘦素敏感性降低,发生了瘦素抵抗。DIO小鼠血浆脂联素水平比DIO-R小鼠低。DIO组TNF-α水平明显高于DIO-R组。  相似文献   

9.
瘦素在哺乳动物体重调节、繁殖和免疫中的作用   总被引:4,自引:1,他引:3  
李兴升  王德华 《兽类学报》2003,23(2):168-174
瘦素(Leptin) 主要是由白色脂肪细胞分泌的、肥胖基因编码的、分子量为16 KD 的蛋白类激素。其N 端具有信号肽序列, 引导蛋白质进入分泌途径, 信号肽被切除后成为有生物学功能的成熟蛋白质。瘦素在动物的体重调节、发育与生殖、免疫和糖代谢等方面有重要作用。瘦素已经不仅仅是脂肪细胞分泌的蛋白类激素, 而是一个在许多方面发挥作用的神经内分泌调节因子。本文综述了瘦素在哺乳动物体重调节、繁殖和免疫中的作用及其调控机制, 主要包括: 动物血清瘦素浓度的季节性变化; 光周期、温度和食物等环境因子对瘦素浓度的影响; 瘦素与解偶联蛋白(Uncoupling proteins , UCPs) 在能量代谢和产热中的互作; 瘦素与下丘脑神经肽Y (Hypothalamus neuropeptide Y, NPY) 在体重调节和产热作用中的拮抗; 瘦素与甲状腺激素和胰岛素在能量代谢中的互作以及瘦素在生殖和免疫中的作用。  相似文献   

10.
为探讨黄葵素对糖尿病肾病肾纤维化治疗作用及机制,采用SPF级C57BLKS/J db/db雄性小鼠20只,随机分为黄葵素低、中、高剂量(97.5、195、390 mg/kg/d)给药组和模型组4组,以同背景的5只db/m小鼠为空白对照组,分别用黄葵素混悬液及等体积的0.5%羧甲基纤维素钠溶液灌胃,连续16周,第24周处死,收集血和肾脏。检测尿ACR、血肌酐、血尿素氮,HE和Masson染色观察肾脏形态学改变和纤维化程度,免疫组化染色检测肾组织巨噬细胞标记F4/80表达情况,Western blot法检测肾组织F4/80蛋白、胶原蛋白III、波形蛋白表达情况,qPCR法检测肾组织TNF-α、IL-1β和iNOS的mRNA水平。结果显示:与模型组相比,黄葵素可以降低db/db小鼠尿ACR、血肌酐、血尿素氮水平,减轻肾脏病理损伤及胶原纤维的沉积,降低肾组织胶原蛋白III、波形蛋白及F4/80蛋白表达,减少肾组织F4/80标记巨噬细胞浸润;并下调了肾组织TNF-α、IL-1β、iNOS的mRNA水平。综上表明黄葵素可有效缓解db/db小鼠肾脏炎症反应,改善肾功能及肾纤维化,发挥肾保护作用,其机制与减少肾组织内巨噬细胞浸润及抑制促炎的M1型巨噬细胞极化相关。  相似文献   

11.
Summary Knowledge of the metabolic changes that occur in insulin-resistant type 2 diabetes is relatively lacking compared to insulin-deficient type 1 diabetes. This paper summarizes the importance of the C57BL/KsJ-db/db mouse as a model of type 2 diabetes, and illustrates the effects that insulin-deficient and insulin-resistant states have on hepatic glycogen metabolism. A longitudinal study of db/db mice of ages 2–15 weeks revealed that significant changes in certain parameters of hepatic glycogen metabolism occur during this period. The liver glycogen levels were similar between diabetic and control mice. However, glycogen particles from db/db mice were on average smaller in mass and had shorter exterior and interior chain lengths. Total phosphorylase and phosphorylase a activities were elevated in the genetically diabetic mice. This was primarily due to an increase in the amount of enzymic protein apparently the result of a decreased rate of degradation. It was not possible to find a consistent alteration in glycogen synthase activity in the db/db mice. Glycogen synthase and phosphorylase from diabetic liver revealed some changes in kinetic properties in the form of a decrease in Vmax, and altered sensitivity to inhibitors like ATP. The altered glycogen structure in db/db mice may have contributed to changes in the activities and properties of glycogen synthase and phosphorylase. The exact role played by hormones (insulin and glucagon) in these changes is not clear but further studies should reveal their contributions. The db/db mouse provides a good model for type 2 diabetes and for fluctuating insulin and glucagon ratios. Its use should clarify the regulation of hepatic glycogen metabolism and other metabolic processes known to be controlled by these hormones. The other animal models of type 2 diabetes, ob/ob mouse and fatty Zucker (fa/fa) rat, show similar impairment of hepatic glycogen metabolism. The concentrations of glycogen metabolizing enzymes are high and in vitro studies indicate enhanced rate of glycogen synthesis and breakdown. However, streptozotocin-induced diabetic animals and BB rats which resemble insulin-deficient type 1 diabetes are characterized by decreased glycogen turnover as a result of reduction in the levels of glycogen metabolizing enzymes.  相似文献   

12.
Although zinc (Zn) deficiency has been associated with insulin resistance, and altered Zn metabolism (e.g., hyperzincuria, low-normal plasma Zn concentrations) may be present in diabetes, the potential effects of Zn on modulation of insulin action in Type II diabetes have not been established. The objective of this study was to compare the effects of dietary Zn deficiency and Zn supplementation on glycemic control in db/db mice. Weanling db/db mice and lean littermate controls were fed Zn-deficient (3 ppm Zn; dbZD and InZD groups), Zn-adequate control (30 ppm Zn; dbC and InC groups) or Zn-supplemented (300 ppm Zn; dbZS and InZS groups) diets for 6 weeks. Mice were assessed for Zn status, serum and urinary indices of diabetes, and gastrocnemius insulin receptor concentration and tyrosine kinase activity. Fasting serum glucose concentrations were significantly lower in the dbZS group compared with the dbZD group (19.3 +/- 2.9 and 27.9 +/- 4.1 mM, respectively), whereas the dbC mice had an intermediate value. There was a negative correlation between femur Zn and serum glucose concentrations (r = -0.59 for lean mice, P = 0.007). The dbZS group had higher pancreatic Zn and lower circulating insulin concentrations than dbZC mice. Insulin-stimulated tyrosine kinase activity in gastrocnemius muscle was higher in the db/db genotype, and insulin receptor concentration was not altered. In summary, dietary Zn supplementation attenuated hyperglycemia and hyperinsulinemia in db/db mice, suggesting that the roles of Zn in pancreatic function and peripheral tissue glucose uptake need to be further investigated.  相似文献   

13.
Control db/+ and diabetic db/db mice at 6 and 12 wk of age were subjected to echocardiography to determine whether contractile function was reduced in vivo and restored in transgenic db/db-human glucose transporter 4 (hGLUT4) mice (12 wk old) in which cardiac metabolism has been normalized. Systolic function was unchanged in 6-wk-old db/db mice, but fractional shortening and velocity of circumferential fiber shortening were reduced in 12-wk-old db/db mice (43.8 +/- 2.1% and 8.3 +/- 0.5 circs/s, respectively) relative to db/+ control mice (59.5 +/- 2.3% and 11.8 +/- 0.4 circs/s, respectively). Doppler flow measurements were unchanged in 6-wk-old db/db mice. The ratio of E and A transmitral flows was reduced from 3.56 +/- 0.29 in db/+ mice to 2.40 +/- 0.20 in 12-wk-old db/db mice, indicating diastolic dysfunction. Thus a diabetic cardiomyopathy with systolic and diastolic dysfunction was evident in 12-wk-old diabetic db/db mice. Cardiac function was normalized in transgenic db/db-hGLUT4 mice, indicating that altered cardiac metabolism can produce contractile dysfunction in diabetic db/db hearts.  相似文献   

14.
Activation of PPARdelta alters lipid metabolism in db/db mice   总被引:11,自引:0,他引:11  
Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors, which heterodimerize with the retinoid X receptor and bind to peroxisome proliferator response elements in the promoters of regulated genes. Despite the wealth of information available on the function of PPARalpha and PPARgamma, relatively little is known about the most widely expressed PPAR subtype, PPARdelta. Here we show that treatment of insulin resistant db/db mice with the PPARdelta agonist L-165041, at doses that had no effect on either glucose or triglycerides, raised total plasma cholesterol concentrations. The increased cholesterol was primarily associated with high density lipoprotein (HDL) particles, as shown by fast protein liquid chromatography analysis. These data were corroborated by the chemical analysis of the lipoproteins isolated by ultracentrifugation, demonstrating that treatment with L-165041 produced an increase in circulating HDL without major changes in very low or low density lipoproteins. White adipose tissue lipoprotein lipase activity was reduced following treatment with the PPARdelta ligand, but was increased by a PPARgamma agonist. These data suggest both that PPARdelta is involved in the regulation of cholesterol metabolism in db/db mice and that PPARdelta ligands could potentially have therapeutic value.  相似文献   

15.
Clinical studies have reported that the incidence and severity of myocardial infarction is significantly greater in diabetics compared with nondiabetics after correction for all other risk factors. The majority of studies investigating the pathophysiology of myocardial ischemia-reperfusion injury have focused on otherwise healthy animals. At present, there is a paucity of experimental investigations on the pathophysiology of heart failure in diabetic animals. We hypothesized that the severity of myocardial reperfusion injury and the development of congestive heart failure would be markedly enhanced in the db/db diabetic mouse. Accordingly, we studied the effects of varying durations of in vivo myocardial ischemia and reperfusion on the incidence of heart failure in db/db diabetic mice. Nondiabetic and db/db diabetic mice (10 wk of age) were subjected to 30, 45, or 60 min of left coronary artery occlusion and 28 days of reperfusion. Survival at 24 h of reperfusion was 100% in nondiabetic mice subjected to 30 min of myocardial ischemia and 88% in nondiabetic mice subjected to 45 min of myocardial ischemia. In contrast, survival was 53% in db/db diabetic mice subjected to 30 min of myocardial ischemia and 44% in db/db mice after 45 min of myocardial ischemia. Prolonged survival in nondiabetic mice was not significantly attenuated when compared during the 28-day follow-up period with all groups experiencing >90% survival. Prolonged survival was significantly decreased in db/db mice after both 30 and 45 min of myocardial ischemia compared with sham controls. Furthermore, we observed a significant degree or left ventricular dilatation, cardiac hypertrophy, and cardiac contractile dysfunction in db/db mice subjected to 45 min of myocardial ischemia and 28 days reperfusion. In nondiabetic mice subjected to 45 min of myocardial ischemia, we failed to observe any changes in left ventricular dimensions or fractional shortening. These studies provide a feasible experimental model system for the investigation of heart failure secondary to acute myocardial infarction in the db/db diabetic mouse.  相似文献   

16.
17.
利用Affymetrix寡核苷酸基因表达谱芯片对2型糖尿病肾病模型动物——db/db小鼠的肾脏基因表达谱进行了研究.在此基础上,利用末端快速扩增法和RT-PCR的方法,对筛选出来的一个糖尿病肾病相关EST进行了cDNA克隆和表达分析.得到了一长为1.7 kb的cDNA片段.序列分析和网上数据库比对发现,此cDNA片段是小鼠表达序列AL023001的一部分.根据AL023001序列设计特异性引物,利用半定量RT-PCR的方法对AL023001在db/db小鼠肾脏、肝脏、脂肪、骨胳肌、脑等组织中的表达情况进行了分析,发现AL023001在db/db小鼠肾脏中的表达情况与基因芯片检测结果吻合,且AL023001在肝脏、脂肪、骨胳肌和脑等糖尿病肾病相关联组织中均有差异表达.这些结果提示:AL023001与db/db小鼠的糖尿病肾病具有相关性.上述工作有利于揭示AL023001基因的功能,探讨糖尿病肾病的分子机制.  相似文献   

18.
Effect of adrenalectomy on the pancreas of db/db mice   总被引:1,自引:0,他引:1  
Adrenalectomy has been performed in the diabetic mouse and the islet immunohistochemistry studied. Adrenalectomy restored blood glucose to normal. Mean islet size of diabetic animals was larger than that of either adrenalectomized diabetic animals or of lean controls. Adrenalectomy restored the immunohistochemical appearance of the islets to normal when examined with anti-insulin, anti-glucagon and anti-somatostatin antisera.  相似文献   

19.
The inhibitory activity of Vigna nakashimae extract against intestinal α-glucosidase was investigated in vitro and in vivo. The extract exerted a significant inhibitory effect against intestinal α-glucosidases. With sucrose-loading, it reduced the peak responses of blood glucose significantly in normal mice. Next, it was administrated to 8-week-old db/db mice for 2 weeks, and then plasma glucose, triglyceride, and total cholesterol levels were measured. The extract significantly suppressed postprandial hyperglycemia and blood glycated hemoglobin in the db/db mice. In addition, it lowered fasting glucose and improved glucose tolerance. Furthermore, it led to significant decreases in plasma triglyceride levels. It reduced endoplasmic reticulum stress in thapsigargin-induced HepG2 cells. Taken together, these results suggest that Vigna nakashimae extract has hypoglycemic and hypolipidemic effects that occur via inhibition of α-glucosidase activity and endoplasmic reticulum stress.  相似文献   

20.
ObjectivesInvestigation of the effect of SGLT2 inhibition by empagliflozin on left ventricular function in a model of diabetic cardiomyopathy.BackgroundSGLT2 inhibition is a new strategy to treat diabetes. In the EMPA-REG Outcome trial empagliflozin treatment reduced cardiovascular and overall mortality in patients with diabetes presumably due to beneficial cardiac effects, leading to reduced heart failure hospitalization. The relevant mechanisms remain currently elusive but might be mediated by a shift in cardiac substrate utilization leading to improved energetic supply to the heart.MethodsWe used db/db mice on high-fat western diet with or without empagliflozin treatment as a model of severe diabetes. Left ventricular function was assessed by pressure catheter with or without dobutamine stress.ResultsTreatment with empagliflozin significantly increased glycosuria, improved glucose metabolism, ameliorated left ventricular diastolic function and reduced mortality of mice. This was associated with reduced cardiac glucose concentrations and decreased calcium/calmodulin-dependent protein kinase (CaMKII) activation with subsequent less phosphorylation of the ryanodine receptor (RyR). No change of cardiac ketone bodies or branched-chain amino acid (BCAA) metabolites in serum was detected nor was cardiac expression of relevant catabolic enzymes for these substrates affected.ConclusionsIn a murine model of severe diabetes empagliflozin-dependent SGLT2 inhibition improved diastolic function and reduced mortality. Improvement of diastolic function was likely mediated by reduced spontaneous diastolic sarcoplasmic reticulum (SR) calcium release but independent of changes in cardiac ketone and BCAA metabolism.  相似文献   

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