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Objective

Zinc-α2 glycoprotein (ZAG) stimulates lipid loss by adipocytes and may be involved in the regulation of adipose tissue metabolism. However, to date no studies have been made in the most extreme of obesity. The aims of this study are to analyze ZAG expression levels in adipose tissue from morbidly obese patients, and their relationship with lipogenic and lipolytic genes and with insulin resistance (IR).

Methods

mRNA expression levels of PPARγ, IRS-1, IRS-2, lipogenic and lipolytic genes and ZAG were quantified in visceral (VAT) and subcutaneous adipose tissue (SAT) of 25 nondiabetic morbidly obese patients, 11 with low IR and 14 with high IR. Plasma ZAG was also analyzed.

Results

The morbidly obese patients with low IR had a higher VAT ZAG expression as compared with the patients with high IR (p = 0.023). In the patients with low IR, the VAT ZAG expression was greater than that in SAT (p = 0.009). ZAG expression correlated between SAT and VAT (r = 0.709, p<0.001). VAT ZAG expression was mainly predicted by insulin, HOMA-IR, plasma adiponectin and expression of adiponectin and ACSS2. SAT ZAG expression was only predicted by expression of ATGL.

Conclusions

ZAG could be involved in modulating lipid metabolism in adipose tissue and is associated with insulin resistance. These findings suggest that ZAG may be a useful target in obesity and related disorders, such as diabetes.  相似文献   

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Objective: Secreted protein acidic and rich in cysteine (SPARC) is expressed in most tissues and is also secreted by adipocytes. The associations of SPARC mRNA expression in visceral adipose tissue (VAT), subcutaneous abdominal adipose tissue (SAT), serum SPARC concentration, and metabolic parameters in Korean women are investigated. Design and Methods: This is a cross‐sectional study. Fifty‐eight women were recruited, of whom 15 women who underwent bariatric surgery for morbid obesity (BMI mean ± SD: 40.2±5.7 kg/m2), 16 who underwent metabolic surgery for type 2 diabetes (BMI: 28.9±4.5 kg/m2), and, as a control group, 27 who underwent gynecological surgery (BMI: 22.7±2.4 kg/m2). Anthropometric variables, metabolic parameters, SPARC mRNA expression in adipose tissue, and serum SPARC concentration were measured. Results: In all subjects, SPARC mRNA expression was significantly higher in SAT than in VAT. Serum SPARC concentrations (mean ± SE) in morbidly obese subjects, subjects with type 2 diabetes, and normal weight subjects were 267.3±40.2 ng/mL, 130.4±33.0 ng/mL, and 53.1±2.8 ng/mL, respectively. SPARC mRNA in SAT was significantly correlated with BMI, whereas SPARC mRNA in VAT was significantly correlated with BMI and VAT area. Serum SPARC concentration was significantly correlated with BMI, waist circumference, total adipose tissue area, and SAT area. After BMI adjustment, serum SPARC concentration was significantly correlated with fasting insulin concentration and HOMA‐IR score. Multivariate regression analysis showed that BMI and HOMA‐IR were independently associated with serum SPARC concentration. Conclusions: Serum SPARC concentration is significantly correlated with obesity indices and might be influenced by insulin resistance. These findings suggest that SPARC may contribute to the metabolic dysregulation associated with obesity in humans.  相似文献   

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Omentin-1 and fatty acid-binding protein 4 (FABP4) are adipose tissue adipokines linked to obesity-associated cardiovascular complications. The aim of this study was to investigate epicardial adipose tissue (EAT) omentin-1 and FABP4 gene expression in obese and non-obese patients with coronary artery disease (CAD). Omentin-1 and FABP4 mRNA levels in EAT and paired subcutaneous adipose tissue (SAT) as well as adipokine serum concentrations were assessed in 77 individuals (61 with CAD; 16 without CAD (NCAD)). EAT FABP4 mRNA level was decreased in obese CAD patients when compared to obese NCAD individuals (p=0.001). SAT FABP4 mRNA level was decreased in CAD patients compared to NCAD individuals without respect to their obesity status (p=0.001). Omentin-1 mRNA level in EAT and SAT did not differ between the CAD and NCAD groups. These findings suggest that omentin-1 gene expression in adipose tissue is not changed during CAD; downregulated FABP4 gene expression in SAT is associated with CAD while EAT FABP4 gene expression is decreased only in obesity-related CAD.  相似文献   

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IL-8 is released from human adipose tissue. Circulating IL-8 is increased in obese compared with lean subjects and is associated with measures of insulin resistance, development of atherosclerosis, and cardiovascular disease. We studied 1) the production and release of IL-8 in vitro from paired samples of subcutaneous (SAT) and visceral (VAT) adipose tissue and 2) the production of IL-8 from whole adipose tissue, isolated adipocytes, and nonfat cells of adipose tissue. IL-8 release from VAT was fourfold higher than from SAT (P < 0.05), and IL-8 mRNA was twofold higher in VAT compared with SAT (P < 0.01). Dexamethasone (50 nM) attenuated IL-8 production by 50% (P < 0.05), and IL-1beta (2 microg/l) increased IL-8 production up to 15-fold (P < 0.001). IL-8 release from whole SAT explants correlated with body mass index (BMI; r = 0.78; P < 0.001), as did IL-8 release from nonfat cells (r = 0.79; P < 0.001). However, no correlation was found between IL-8 release from the fraction of isolated adipocytes and BMI (r = 0.01). In conclusion, we demonstrated an increased release of IL-8 from VAT compared with SAT. Furthermore, our data suggest that the observed elevation in circulating levels of IL-8 in obese subjects is due primarily to the release of IL-8 from nonfat cells from adipose tissue. The high levels of IL-8 release from human adipose tissue and accumulation of this tissue in obese subjects may account for some of the increase in circulating IL-8 observed in obesity.  相似文献   

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目的:探讨妊娠期糖尿病孕妇内脂素水平与糖代谢的关系.方法:检测血清中内脂素、FIN、FIG水平,计算HOMA-IR,用RT-PCR法检测脂肪组织中内脂素mRNA的表达.结果:(1)妊娠期糖尿病组孕妇血清内脂素、FPG、HOMA-IR、FIN明显高于对照组.(2)妊娠期糖尿病组孕妇内脏脂肪组织中的内脂素的表达明显高于对照组,且妊娠期糖尿病组孕妇内脏组织中内脂素的表达明显高于表皮脂肪组织.(3)血清中内脂素的水平与内脏脂肪组织及HOMA-IR呈正相关.结论:妊娠期糖尿病孕妇脂肪组织中内脂素表达上调,导致血液循环中内脂素水平升高,参与GDM孕妇血糖调节.  相似文献   

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Background

Obesity is widely recognised as an important risk factor for colorectal cancer (CC).

Aim

The study aimed to evaluate the effect of CC on circulating concentrations and gene expression levels of inflammatory and angiogenesis-related factors in human visceral adipose tissue (VAT).

Methods

VAT biopsies were obtained from 18 healthy individuals and 11 patients with CC. Real-time polymerase chain reactions were performed to quantify gene expression levels and zymographic analyses were used to determine the activity of matrix metalloproteinases (MMPs).

Results

Patients with CC exhibited increased mRNA expression levels of lipocalin-2 (P=.014), osteopontin (P=.027), tumor necrosis factor-α (TNF-α) (P=.016) and chitinase-3 like-1 (P=.006) compared to control subjects in VAT. Gene expression levels of hypoxia-inducible factor-1 α, vascular endothelial growth factor and MMP-2 were significantly higher (P<.05) in VAT of patients with CC. The expression of insulin-like growth factor I, insulin growth factor binding protein 3 and MMP-9 followed the same trend, although no significant differences were reached. The enzymatic activity of MMP-9 was increased (P<.001) in patients with CC. Furthermore, individuals with CC showed increased (P<.05) circulating concentrations of the inflammatory markers interleukin-6, tumour necrosis factor α and hepatocyte growth factor, whereas levels of the anti-inflammatory adipokine adiponectin were decreased (P<.01).

Conclusion

These findings represent the first observation that mRNA levels of the novel inflammatory factors lipocalin-2, chitinase-3 like-1 and osteopontin are increased in human VAT of subjects with CC. This observation together with the up-regulation of angiogenic factors suggests that adipokines secreted by VAT may be involved in the development of colon cancer.  相似文献   

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The aim of this study was to determine whether amyloid precursor protein (APP) is expressed in human adipose tissue, dysregulated in obesity, and related to insulin resistance and inflammation. APP expression was examined by microarray expression profiling of subcutaneous abdominal adipocytes (SAC) and cultured preadipocytes from obese and nonobese subjects. Quantitative real-time PCR (QPCR) was performed to confirm differences in APP expression in SAC and to compare APP expression levels in adipose tissue, adipocytes, and stromal vascular cells (SVCs) from subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) specimens. Adipose tissue samples were also examined by western blot and immunofluorescence confocal microscopy. Microarray studies demonstrated that APP mRNA expression levels were higher in SAC (approximately 2.5-fold) and preadipocytes (approximately 1.4) from obese subjects. Real-time PCR confirmed increased APP expression in SAC in a separate group of obese compared with nonobese subjects (P=0.02). APP expression correlated to in vivo indices of insulin resistance independently of BMI and with the expression of proinflammatory genes, such as monocyte chemoattractant protein-1 (MCP-1) (R=0.62, P=0.004), macrophage inflammatory protein-1alpha (MIP-1alpha) (R=0.60, P=0.005), and interleukin-6 (IL-6) (R=0.71, P=0.0005). Full-length APP protein was detected in adipocytes by western blotting and APP and its cleavage peptides, Abeta40 and Abeta42, were observed in SAT and VAT by immunofluorescence confocal microscopy. In summary, APP is highly expressed in adipose tissue, upregulated in obesity, and expression levels correlate with insulin resistance and adipocyte cytokine expression levels. These data suggest a possible role for APP and/or Abeta in the development of obesity-related insulin resistance and adipose tissue inflammation.  相似文献   

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Background

Hepatogenous diabetes (HD) occurs as a complication of cirrhosis. Whether genetic factors, rather than only liver damage, play roles in the development of HD is unknown. TCF7L2 gene has been reported to be associated with type 2 diabetes and also cancer risks. We aim to evaluate the impact of TCF7L2 gene on the susceptibility of HD and hepatocellular carcinoma (HCC) in a Chinese Han population.

Patients and methods

A total of 367 adult liver transplant candidates with liver cirrhosis were included. Fifteen tag single nucleotide polymorphisms (SNPs) were selected from HapMap CHB database with a minor allele frequency of > 0.2 and r2 of > 0.8. Another three SNPs were also chosen because of their close association with type 2 diabetes in East Asian.

Results

Patients with HD presented significantly poorer liver function, higher incidence of cirrhotic complications and higher insulin resistance compared with non-HD patients. Three SNPs were differentially distributed between HD patients and non-HD patients. In multivariate logistic analysis, TCF7L2 rs290487 and rs6585194 polymorphisms were independently associated with HD after adjustment of clinical factors. The TCF7L2 rs290487 C/C variant homozygote showed much higher insulin resistance and significantly increased HD risk comparing with T/T and T/C genotypes, while the genetic variant of rs6585194 was protectively against HD. Three SNPs (rs290481, rs290487 and rs290489) located near the 3′ end of TCF7L2 gene were associated with HCC risk with marginal significance. Patients carrying G-C-A haplotype had a significantly higher HCC risk than those with A-T-G.

Conclusions

TCF7L2 polymorphisms were associated with HD and maybe cancer risk as well. Further studies with large samples are needed to verify these results.  相似文献   

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Plasma acutephase protein pentraxin 3 (PTX3) concentration is dysregulated in human obesity and metabolic syndrome. Here, we explore its relationship with insulin secretion and sensitivity, obesity markers, and adipose tissue PTX3 gene expression. Plasma PTX3 protein levels were analyzed in a cohort composed of 27 lean [body mass index (BMI) ≤ 25 kg/m(2)] and 48 overweight (BMI 25-30 kg/m(2)) men (cohort 1). In this cohort, plasma PTX3 was negatively correlated with fasting triglyceride levels and insulin secretion after intravenous and oral glucose administration. Plasma PTX3 protein and PTX3 gene expression in visceral (VAT) and subcutaneous (SAT) whole adipose tissue and adipocyte and stromovascular fractions were analyzed in cohort 2, which was composed of 19 lean, 28 overweight, and 15 obese subjects (BMI >30 kg/m(2)). An inverse association with body weight and waist/hip ratio was observed in cohort 2. In VAT depots, PTX3 mRNA levels were higher in subjects with BMI >25 kg/m(2) than in lean subjects, positively correlated with IL-1β mRNA levels, and higher in the adipocyte than stromovascular fraction. Human preadipocyte SGBS cell line was used to study PTX3 production in response to factors that obesity entails. In SGBS adipocytes, PTX3 gene expression was enhanced by IL-1β and TNFα but not IL-6 or insulin. In conclusion, the negative correlation between PTX3 and glucose-stimulated insulin secretion suggests a role for PTX3 in metabolic control. PTX3 gene expression is upregulated in VAT depots in obesity, despite lower plasma PTX3 protein, and by some proinflammatory cytokines in cultured adipocytes.  相似文献   

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Risk alleles within a gene desert at the 9p21 locus constitute the most prevalent genetic determinant of cardiovascular disease. Previous research has demonstrated that 9p21 risk variants influence gene expression in vascular tissues, yet the biological mechanisms by which this would mediate atherosclerosis merits further investigation. To investigate possible influences of this locus on other tissues, we explored expression patterns of 9p21-regulated genes in a panel of multiple human tissues and found that the tumor suppressor CDKN2B was highly expressed in subcutaneous adipose tissue (SAT). CDKN2B expression was regulated by obesity status, and this effect was stronger in carriers of 9p21 risk alleles. Covariation between expression of CDKN2B and genes implemented in adipogenesis was consistent with an inhibitory effect of CDKN2B on SAT proliferation. Moreover, studies of postprandial triacylglycerol clearance indicated that CDKN2B is involved in down-regulation of SAT fatty acid trafficking. CDKN2B expression in SAT correlated with indicators of ectopic fat accumulation, including markers of hepatic steatosis. Among genes regulated by 9p21 risk variants, CDKN2B appears to play a significant role in the regulation of SAT expandability, which is a strong determinant of lipotoxicity and therefore might contribute to the development of atherosclerosis.  相似文献   

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Obesity is a complex disorder caused by several factors. Thus, the aim of the present study was to assess whether the expression of genes in the omental white adipose tissue (AT) of subjects with insulin resistance (IR) or metabolic syndrome (MetS) is associated with an elevation in serum branched-chain amino acids (BCAAs) and whether this response depends on specific genetic variants. Serum BCAA concentration, the adipocyte area, and gene variants of PPARγ, ABCA1, FTO, TCF7L2, GFOD2,BCAT2, and BCKDH were determined in 115 Mexican subjects. The gene expression in the AT and adipocytes of BCAT, BCKDH E1α, C/EBPα, PPARγ2, SREBP-1, PPARα, UCP1, leptin receptor, leptin, adiponectin, and TNFα was measured in 51 subjects. Subjects with IR showed higher values for the BMI, HOMA-IR, and adipocyte area and higher levels of serum glucose, insulin, leptin, and C-reactive protein, as well as an elevation of the AT gene expression of SREBP-1, leptin, and TNFα and a significant reduction in the expression of adiponectin, BCAT2, and BCKDH E1α, compared with non-IR subjects. The presence of MetS was associated with higher HOMA-IR as well as higher serum BCAA concentrations. Subjects with the genetic variants for BCAT2 and BCKDH E1 α showed a lower serum BCAA concentration, and those with the ABCA1 and FTO gene variant showed higher levels of insulin and HOMA-IR than non-IR subjects. AT dysfunction is the result of a combination of the presence of some genetic variants, altered AT gene expression, the presence of MetS risk factors, IR, and serum BCAA concentrations.  相似文献   

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Animal studies have revealed the association between stearoyl-CoA desaturase 1 (SCD1) and obesity and insulin resistance. However, only a few studies have been undertaken in humans. We studied SCD1 in visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) from morbidly obese patients and their association with insulin resistance, sterol regulatory element binding protein-1 (SREBP-1) and ATPase p97, proteins involved in SCD1 synthesis and degradation. The insulin resistance was calculated in 40 morbidly obese patients and 11 overweight controls. Measurements were made of VAT and SAT SCD1, SREBP-1 and ATPase p97 mRNA expression and protein levels. VAT and SAT SCD1 mRNA expression levels in the morbidly obese patients were significantly lower than in the controls (P = 0.006), whereas SCD1 protein levels were significantly higher (P < 0.001). In the morbidly obese patients, the VAT SCD1 protein levels were decreased in patients with higher insulin resistance (P = 0.007). However, SAT SCD1 protein levels were increased in morbidly obese patients with higher insulin resistance (P < 0.05). Multiple linear regressions in the morbidly obese patients showed that the variable associated with the SCD1 protein levels in VAT was insulin resistance, and the variables associated with SCD1 protein levels in SAT were body mass index (BMI) and ATPase p97. In conclusion, these data suggest that the regulation of SCD1 is altered in individuals with morbid obesity and that the SCD1 protein has a different regulation in the two adipose tissues, as well as being closely linked to the degree of insulin resistance.  相似文献   

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Objective: Our goal was to test any association between human plasma circulating levels of monocyte chemoattractant protein‐1 (cMCP‐1) and insulin resistance and to compare monocyte chemoattractant protein‐1 (MCP‐1) adipose tissue gene expression and cMCP‐1 in relation with inflammatory markers. Research Methods and Procedures: cMCP‐1 was measured in n = 116 consecutive control male subjects to whom an insulin sensitivity (Si) test was performed. Circulating levels of soluble CD14, soluble tumor necrosis factor receptor type 2 (sTNFR2), soluble interleukin‐6 (sIL‐6), and adiponectin also were measured. Subcutaneous adipose tissue samples were obtained from n = 107 non‐diabetic and type 2 diabetic subjects with different degrees of obesity. Real‐time polymerase chain reaction was used to measure gene expression of MCP‐1, CD68, tumor necrosis factor‐α (TNF‐α), and its receptor TNFR2. Results: In the Si study, no independent effect of cMCP‐1 levels on insulin sensitivity was observed. In the expression study, in non‐diabetic subjects, MCP‐1 mRNA had a positive correlation with BMI (r = 0.407, p = 0.003), TNF‐α mRNA (r = 0.419, p = 0.002), and TNFR2 mRNA (r = 0.410, p = 0.003). In these subjects, cMCP‐1 was found to correlate with waist‐to‐hip ratio (r = 0.322, p = 0.048). In patients with type 2 diabetes, MCP‐1 mRNA was up‐regulated compared with non‐diabetic subjects. TNF‐α mRNA was found to independently contribute to MCP‐1 mRNA expression. In this group, CD68 mRNA was found to correlate with BMI (r = 0.455, p = 0.001). Discussion: cMCP‐1 is not associated with insulin sensitivity in apparently healthy men. TNF‐α is the inflammatory cytokine associated with MCP‐1 expression in subcutaneous adipose tissue.  相似文献   

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Atrial- and brain-type natriuretic peptides (ANP and BNP, respectively) have been shown to exert potent lipolytic action in adipocytes. A family of natriuretic peptide receptors (NPRs), NPR-1, NPR-2, and NPR-3, mediates their physiologic effects. NPR-1 and NPR-2 are receptor guanylyl cyclases, while NPR-3 lacks enzymatic activity and functions primarily as a clearance receptor for natriuretic peptides. ANP has a high affinity for NPR-1 and NPR-3 than other natriuretic peptides. There is a possibility that ANP may exhibit its lipolytic effect through the balance of NPR-1 and NPR-3 expressions in adipocytes. However, the regulation of adipose NPRs has not been fully elucidated. We here examined the regulation of mouse adipose NPRs by insulin, an anti-lipolytic hormone. Among the insulin target organs, NPR-1 mRNA levels were higher in white adipose tissue (WAT) than in liver and skeletal muscle. NPR-3 mRNA was expressed most abundantly in WAT. Fasting condition induced NPR-1 mRNA level while suppressed NPR-3 mRNA level in WAT. Administration of streptozotocin resulted in the increase of NPR-1 mRNA level while the decrease of NPR-3 mRNA level in WAT. In ob/ob mice, hyperinsulinemic model, NPR-1 mRNA level was lower whereas NPR-3 mRNA level was higher compared to lean control mice. In 3T3-L1 adipocytes, insulin significantly reduced NPR-1 mRNA level while increased NPR-3 mRNA levels both through phosphatidylinositol 3-kinase (PI3-kinase) pathway. In summary, NPR-1 and NPR-3 were highly expressed in WAT and adipose NPR-1 and NPR-3 were reciprocally regulated by insulin. This study suggests that insulin may efficiently promote lipogenesis partly by reducing the lipolytic action of ANP through the opposite regulation of NPR-1 and NPR-3.  相似文献   

19.
Adipose tissue represents a complex tissue both in terms of its cellular composition, as it includes mature adipocytes and the various cell types comprising the stromal‐vascular fraction (SVF), and in relation to the distinct biochemical, morphological and functional characteristics according to its anatomical location. Herein, we have characterized the proteomic profile of both mature adipocyte and SVF from human visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) fat depots in order to unveil differences in the expression of proteins which may underlie the distinct association of VAT and SAT to several pathologies. Specifically, 24 proteins were observed to be differentially expressed between SAT SVF versus VAT SVF from lean individuals. Immunoblotting and RT‐PCR analysis confirmed the differential regulation of the nuclear envelope proteins lamin A/C, the membrane‐cytoskeletal linker ezrin and the enzyme involved in retinoic acid production, aldehyde dehydrogenase 1A2, in the two fat depots. In sum, the observation that proteins with important cell functions are differentially distributed between VAT and SAT and their characterization as components of SVF or mature adipocytes pave the way for future research on the molecular basis underlying diverse adipose tissue‐related pathologies such as metabolic syndrome or lipodystrophy.  相似文献   

20.
Objective: Increased mRNA and activity levels of 11β‐hydroxysteroid dehydrogenase type 1 (11βHSD1) in human adipose tissue (AT) are associated with obesity and insulin resistance. The aim of our study was to investigate whether 11βHSD1 expression or activity in abdominal subcutaneous AT of non‐diabetic subjects are associated with subsequent changes in body weight and insulin resistance [homeostasis model assessment of insulin resistance (HOMA‐IR)]. Research Methods and Procedures: Prospective analyses were performed in 20 subjects (two whites and 18 Pima Indians) who had baseline measurements of 11βHSD1 mRNA and activity in whole AT (follow‐up, 0.3 to 4.9 years) and in 47 Pima Indians who had baseline assessments of 11βHSD1 mRNA in isolated adipocytes (follow‐up, 0.8 to 5.3 years). Results: In whole AT, although 11βHSD1 mRNA levels showed positive associations with changes in weight and HOMA‐IR, 11βHSD1 activity was associated with changes in HOMA‐IR but not in body weight. 11βHSD1 mRNA levels in isolated adipocytes were not associated with follow‐up changes in any of the anthropometric or metabolic variables. Discussion: Our results indicate that increased expression of 11βHSD1 in subcutaneous abdominal AT may contribute to risk of worsening obesity and insulin resistance. This prospective relationship does not seem to be mediated by increased 11βHSD1 expression in adipocytes.  相似文献   

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