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Flagellar motility mediates biofilm formation in Aeromonas dhakensis

Lau TV, Puah SM, Tan JMA, Merino S, Puthucheary SD, Chua KH

Microb Pathog, 2023 Apr;177:106059.
PMID: 36878334 DOI: 10.1016/j.micpath.2023.106059

Aeromonas dhakensis possesses dual flagellar systems for motility under different environments. Flagella-mediated motility is necessary for biofilm formation through an initial attachment of bacteria to the surface, but this has not been elucidated in A. dhakensis. This study investigates the role of polar (flaH, maf1) and lateral (lafB, lafK and lafS) flagellar genes in the biofilm formation of a clinical A. dhakensis strain WT187 isolated from burn wound infection. Five deletion mutants and corresponding complemented strains were constructed using pDM4 and pBAD33 vectors, respectively, and analyzed for motility and biofilm formation using crystal violet staining and real-time impedance-based assays. All mutants were significantly reduced in swimming (p
Fulltext Can the intake of antiparasitic secondary metabolites explain the low prevalence of hemoparasites among wild Psittaciformes?

Masello JF, Martínez J, Calderón L, Wink M, Quillfeldt P, Sanz V, et al.

Parasit Vectors, 2018 Jun 19;11(1):357.
PMID: 29921331 DOI: 10.1186/s13071-018-2940-3

BACKGROUND: Parasites can exert selection pressure on their hosts through effects on survival, on reproductive success, on sexually selected ornament, with important ecological and evolutionary consequences, such as changes in population viability. Consequently, hemoparasites have become the focus of recent avian studies. Infection varies significantly among taxa. Various factors might explain the differences in infection among taxa, including habitat, climate, host density, the presence of vectors, life history and immune defence. Feeding behaviour can also be relevant both through increased exposure to vectors and consumption of secondary metabolites with preventative or therapeutic effects that can reduce parasite load. However, the latter has been little investigated. Psittaciformes (parrots and cockatoos) are a good model to investigate these topics, as they are known to use biological control against ectoparasites and to feed on toxic food. We investigated the presence of avian malaria parasites (Plasmodium), intracellular haemosporidians (Haemoproteus, Leucocytozoon), unicellular flagellate protozoans (Trypanosoma) and microfilariae in 19 Psittaciformes species from a range of habitats in the Indo-Malayan, Australasian and Neotropical regions. We gathered additional data on hemoparasites in wild Psittaciformes from the literature. We considered factors that may control the presence of hemoparasites in the Psittaciformes, compiling information on diet, habitat, and climate. Furthermore, we investigated the role of diet in providing antiparasitic secondary metabolites that could be used as self-medication to reduce parasite load.
RESULTS: We found hemoparasites in only two of 19 species sampled. Among them, all species that consume at least one food item known for its secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, were free from hemoparasites. In contrast, the infected parrots do not consume food items with antimalarial or even general antiparasitic properties. We found that the two infected species in this study consumed omnivorous diets. When we combined our data with data from studies previously investigating blood parasites in wild parrots, the positive relationship between omnivorous diets and hemoparasite infestation was confirmed. Individuals from open habitats were less infected than those from forests.
CONCLUSIONS: The consumption of food items known for their secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, as well as the higher proportion of infected species among omnivorous parrots, could explain the low prevalence of hemoparasites reported in many vertebrates.
Fulltext Socioeconomic Effect of Education on Pancreatic Cancer Risk in Western Europe: An Update on the EPIC Cohorts Study

Cirera L, Huerta JM, Chirlaque MD, Overvad K, Lindström M, Regnér S, et al.

Cancer Epidemiol Biomarkers Prev, 2019 06;28(6):1089-1092.
PMID: 31160392 DOI: 10.1158/1055-9965.EPI-18-1153

BACKGROUND: To analyze the potential effect of social inequality on pancreatic cancer risk in Western Europe, by reassessing the association within the European Prospective Investigation into Cancer and Nutrition (EPIC) Study, including a larger number of cases and an extended follow-up.
METHODS: Data on highest education attained were gathered for 459,170 participants (70% women) from 10 European countries. A relative index of inequality (RII) based on adult education was calculated for comparability across countries and generations. Cox regression models were applied to estimate relative inequality in pancreatic cancer risk, stratifying by age, gender, and center, and adjusting for known pancreatic cancer risk factors.
RESULTS: A total of 1,223 incident pancreatic cancer cases were included after a mean follow-up of 13.9 (±4.0) years. An inverse social trend was found in models adjusted for age, sex, and center for both sexes [HR of RII, 1.27; 95% confidence interval (CI), 1.02-1.59], which was also significant among women (HR, 1.42; 95% CI, 1.05-1.92). Further adjusting by smoking intensity, alcohol consumption, body mass index, prevalent diabetes, and physical activity led to an attenuation of the RII risk and loss of statistical significance.
CONCLUSIONS: The present reanalysis does not sustain the existence of an independent social inequality influence on pancreatic cancer risk in Western European women and men, using an index based on adult education, the most relevant social indicator linked to individual lifestyles, in a context of very low pancreatic cancer survival from (quasi) universal public health systems.
IMPACT: The results do not support an association between education and risk of pancreatic cancer.
Fulltext Prediagnostic Plasma Bile Acid Levels and Colon Cancer Risk: A Prospective Study

Kühn T, Stepien M, López-Nogueroles M, Damms-Machado A, Sookthai D, Johnson T, et al.

J Natl Cancer Inst, 2020 May 01;112(5):516-524.
PMID: 31435679 DOI: 10.1093/jnci/djz166

BACKGROUND: Bile acids have been proposed to promote colon carcinogenesis. However, there are limited prospective data on circulating bile acid levels and colon cancer risk in humans.
METHODS: Associations between prediagnostic plasma levels of 17 primary, secondary, and tertiary bile acid metabolites (conjugated and unconjugated) and colon cancer risk were evaluated in a nested case-control study within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Bile acid levels were quantified by tandem mass spectrometry in samples from 569 incident colon cancer cases and 569 matched controls. Multivariable logistic regression analyses were used to estimate odds ratios (ORs) for colon cancer risk across quartiles of bile acid concentrations.
RESULTS: Positive associations were observed between colon cancer risk and plasma levels of seven conjugated bile acid metabolites: the primary bile acids glycocholic acid (ORquartile 4 vs quartile 1= 2.22, 95% confidence interval [CI] = 1.52 to 3.26), taurocholic acid (OR = 1.78, 95% CI = 1.23 to 2.58), glycochenodeoxycholic acid (OR = 1.68, 95% CI = 1.13 to 2.48), taurochenodeoxycholic acid (OR = 1.62, 95% CI = 1.11 to 2.36), and glycohyocholic acid (OR = 1.65, 95% CI = 1.13 to 2.40), and the secondary bile acids glycodeoxycholic acid (OR = 1.68, 95% CI = 1.12 to 2.54) and taurodeoxycholic acid (OR = 1.54, 95% CI = 1.02 to 2.31). By contrast, unconjugated bile acids and tertiary bile acids were not associated with risk.
CONCLUSIONS: This prospective study showed that prediagnostic levels of certain conjugated primary and secondary bile acids were positively associated with risk of colon cancer. Our findings support experimental data to suggest that a high bile acid load is colon cancer promotive.
Fulltext CA19-9 and apolipoprotein-A2 isoforms as detection markers for pancreatic cancer: a prospective evaluation

Honda K, Katzke VA, Hüsing A, Okaya S, Shoji H, Onidani K, et al.

Int J Cancer, 2019 Apr 15;144(8):1877-1887.
PMID: 30259989 DOI: 10.1002/ijc.31900

Recently, we identified unique processing patterns of apolipoprotein A2 (ApoA2) in patients with pancreatic cancer. Our study provides a first prospective evaluation of an ApoA2 isoform ("ApoA2-ATQ/AT"), alone and in combination with carbohydrate antigen 19-9 (CA19-9), as an early detection biomarker for pancreatic cancer. We performed ELISA measurements of CA19-9 and ApoA2-ATQ/AT in 156 patients with pancreatic cancer and 217 matched controls within the European EPIC cohort, using plasma samples collected up to 60 months prior to diagnosis. The detection discrimination statistics were calculated for risk scores by strata of lag-time. For CA19-9, in univariate marker analyses, C-statistics to distinguish future pancreatic cancer patients from cancer-free individuals were 0.80 for plasma taken ≤6 months before diagnosis, and 0.71 for >6-18 months; for ApoA2-ATQ/AT, C-statistics were 0.62, and 0.65, respectively. Joint models based on ApoA2-ATQ/AT plus CA19-9 significantly improved discrimination within >6-18 months (C = 0.74 vs. 0.71 for CA19-9 alone, p = 0.022) and ≤ 18 months (C = 0.75 vs. 0.74, p = 0.022). At 98% specificity, and for lag times of ≤6, >6-18 or ≤ 18 months, sensitivities were 57%, 36% and 43% for CA19-9 combined with ApoA2-ATQ/AT, respectively, vs. 50%, 29% and 36% for CA19-9 alone. Compared to CA19-9 alone, the combination of CA19-9 and ApoA2-ATQ/AT may improve detection of pancreatic cancer up to 18 months prior to diagnosis under usual care, and may provide a useful first measure for pancreatic cancer detection prior to imaging.
Fulltext Gallstones and incident colorectal cancer in a large pan-European cohort study

Ward HA, Murphy N, Weiderpass E, Leitzmann MF, Aglago E, Gunter MJ, et al.

Int J Cancer, 2019 Sep 15;145(6):1510-1516.
PMID: 30585640 DOI: 10.1002/ijc.32090

Gallstones, a common gastrointestinal condition, can lead to several digestive complications and can result in inflammation. Risk factors for gallstones include obesity, diabetes, smoking and physical inactivity, all of which are known risk factors for colorectal cancer (CRC), as is inflammation. However, it is unclear whether gallstones are a risk factor for CRC. We examined the association between history of gallstones and CRC in the European Prospective Investigation into Cancer and Nutrition (EPIC) study, a prospective cohort of over half a million participants from ten European countries. History of gallstones was assessed at baseline using a self-reported questionnaire. The analytic cohort included 334,986 participants; a history of gallstones was reported by 3,917 men and 19,836 women, and incident CRC was diagnosed among 1,832 men and 2,178 women (mean follow-up: 13.6 years). Hazard ratios (HR) and 95% confidence intervals (CI) for the association between gallstones and CRC were estimated using Cox proportional hazards regression models, stratified by sex, study centre and age at recruitment. The models were adjusted for body mass index, diabetes, alcohol intake and physical activity. A positive, marginally significant association was detected between gallstones and CRC among women in multivariable analyses (HR = 1.14, 95%CI 0.99-1.31, p = 0.077). The relationship between gallstones and CRC among men was inverse but not significant (HR = 0.81, 95%CI 0.63-1.04, p = 0.10). Additional adjustment for details of reproductive history or waist circumference yielded minimal changes to the observed associations. Further research is required to confirm the nature of the association between gallstones and CRC by sex.
Fulltext Pre-diagnostic copper and zinc biomarkers and colorectal cancer risk in the European Prospective Investigation into Cancer and Nutrition cohort

Stepien M, Jenab M, Freisling H, Becker NP, Czuban M, Tjønneland A, et al.

Carcinogenesis, 2017 Jul 01;38(7):699-707.
PMID: 28575311 DOI: 10.1093/carcin/bgx051

Adequate intake of copper and zinc, two essential micronutrients, are important for antioxidant functions. Their imbalance may have implications for development of diseases like colorectal cancer (CRC), where oxidative stress is thought to be etiologically involved. As evidence from prospective epidemiologic studies is lacking, we conducted a case-control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort to investigate the association between circulating levels of copper and zinc, and their calculated ratio, with risk of CRC development. Copper and zinc levels were measured by reflection X-ray fluorescence spectrometer in 966 cases and 966 matched controls. Multivariable adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated using conditional logistic regression and are presented for the fifth versus first quintile. Higher circulating concentration of copper was associated with a raised CRC risk (OR = 1.50; 95% CI: 1.06, 2.13; P-trend = 0.02) whereas an inverse association with cancer risk was observed for higher zinc levels (OR = 0.65; 95% CI: 0.43, 0.97; P-trend = 0.07). Consequently, the ratio of copper/zinc was positively associated with CRC (OR = 1.70; 95% CI: 1.20, 2.40; P-trend = 0.0005). In subgroup analyses by follow-up time, the associations remained statistically significant only in those diagnosed within 2 years of blood collection. In conclusion, these data suggest that copper or copper levels in relation to zinc (copper to zinc ratio) become imbalanced in the process of CRC development. Mechanistic studies into the underlying mechanisms of regulation and action are required to further examine a possible role for higher copper and copper/zinc ratio levels in CRC development and progression.
Fulltext Consumption of Fish Is Not Associated with Risk of Differentiated Thyroid Carcinoma in the European Prospective Investigation into Cancer and Nutrition (EPIC) Study

Zamora-Ros R, Castañeda J, Rinaldi S, Cayssials V, Slimani N, Weiderpass E, et al.

J Nutr, 2017 Jul;147(7):1366-1373.
PMID: 28592517 DOI: 10.3945/jn.117.247874

Background: Differentiated thyroid cancer (TC) is the most common endocrine cancer. Fish can be an important source of iodine and other micronutrients and contaminants that may affect the thyroid gland and TC risk.Objective: We prospectively evaluated the relations between the consumption of total fish and different fish types and shellfish and TC risk in the EPIC (European Prospective Investigation into Cancer and Nutrition) study.Methods: EPIC is a cohort of >500,000 men and women, mostly aged 35-70 y, who were recruited in 10 European countries. After a mean follow-up of 14 y, 748 primary differentiated TC cases were diagnosed; 666 were in women and 601 were papillary TC. Data on intakes of lean fish, fatty fish, fish products, and shellfish were collected by using country-specific validated dietary questionnaires at recruitment. Multivariable Cox regression was used to calculate HRs and 95% CIs adjusted for many potential confounders, including dietary and nondietary factors.Results: No significant association was observed between total fish consumption and differentiated TC risk for the highest compared with the lowest quartile (HR: 1.03; 95% CI: 0.81, 1.32; P-trend = 0.67). Likewise, no significant association was observed with the intake of any specific type of fish, fish product, or shellfish. No significant heterogeneity was found by TC subtype (papillary or follicular tumors), by sex, or between countries with low and high TC incidence.Conclusion: This large study shows that the intake of fish and shellfish was not associated with differentiated TC risk in Europe, a region in which iodine deficiency or excess is rare.
Fulltext Exogenous hormone use and cutaneous melanoma risk in women: The European Prospective Investigation into Cancer and Nutrition

Cervenka I, Al Rahmoun M, Mahamat-Saleh Y, Fournier A, Boutron-Ruault MC, Severi G, et al.

Int J Cancer, 2020 Jun 15;146(12):3267-3280.
PMID: 31506954 DOI: 10.1002/ijc.32674

Evidence suggests an influence of sex hormones on cutaneous melanoma risk, but epidemiologic findings are conflicting. We examined the associations between use of oral contraceptives (OCs) and menopausal hormone therapy (MHT) and melanoma risk in women participating in the European Prospective Investigation into Cancer and Nutrition (EPIC). EPIC is a prospective cohort study initiated in 1992 in 10 European countries. Information on exogenous hormone use at baseline was derived from country-specific self-administered questionnaires. We used Cox proportional hazards regression models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). Over 1992-2015, 1,696 melanoma cases were identified among 334,483 women, whereof 770 cases among 134,758 postmenopausal women. There was a positive, borderline-significant association between OC use and melanoma risk (HR = 1.12, 95% CI = 1.00-1.26), with no detected heterogeneity across countries (phomogeneity = 0.42). This risk increased linearly with duration of use (ptrend = 0.01). Among postmenopausal women, ever use of MHT was associated with a nonsignificant increase in melanoma risk overall (HR = 1.14, 95% CI = 0.97-1.43), which was heterogeneous across countries (phomogeneity = 0.05). Our findings do not support a strong and direct association between exogenous hormone use and melanoma risk. In order to better understand these relations, further research should be performed using prospectively collected data including detailed information on types of hormone, and on sun exposure, which may act as an important confounder or effect modifier on these relations.
Fulltext Mediation analysis of the alcohol-postmenopausal breast cancer relationship by sex hormones in the EPIC cohort

Assi N, Rinaldi S, Viallon V, Dashti SG, Dossus L, Fournier A, et al.

Int J Cancer, 2020 Feb 01;146(3):759-768.
PMID: 30968961 DOI: 10.1002/ijc.32324

Alcohol consumption is associated with higher risk of breast cancer (BC); however, the biological mechanisms underlying this association are not fully elucidated, particularly the extent to which this relationship is mediated by sex hormone levels. Circulating concentrations of estradiol, testosterone, their free fractions and sex-hormone binding globulin (SHBG), were examined in 430 incident BC cases and 645 matched controls among alcohol-consuming postmenopausal women nested within the European Prospective Investigation into Cancer and Nutrition. Mediation analysis was applied to assess whether individual hormone levels mediated the relationship between alcohol intake and BC risk. An alcohol-related hormonal signature, obtained by partial least square (PLS) regression, was evaluated as a potential mediator. Total (TE), natural direct and natural indirect effects (NIE) were estimated. Alcohol intake was positively associated with overall BC risk and specifically with estrogen receptor-positive tumors with respectively TE = 1.17(95%CI: 1.01,1.35) and 1.36(1.08,1.70) for a 1-standard deviation (1-SD) increase of intake. There was no evidence of mediation by sex steroids or SHBG separately except for a weak indirect effect through free estradiol where NIE = 1.03(1.00,1.06). However, an alcohol-related hormonal signature negatively associated with SHBG and positively with estradiol and testosterone was associated with BC risk (odds ratio [OR] = 1.25 [1.07,1.47]) for a 1-SD higher PLS score, and had a statistically significant NIE accounting for a mediated proportion of 24%. There was limited evidence of mediation of the alcohol-BC association by individual sex hormones. However, a hormonal signature, reflecting lower levels of SHBG and higher levels of sex steroids, mediated a substantial proportion of the association.
Fulltext Circulating insulin-like growth factor I in relation to melanoma risk in the European prospective investigation into cancer and nutrition

Bradbury KE, Appleby PN, Tipper SJ, Travis RC, Allen NE, Kvaskoff M, et al.

Int J Cancer, 2019 03 01;144(5):957-966.
PMID: 30191956 DOI: 10.1002/ijc.31854

Insulin-like growth factor-I (IGF-I) regulates cell proliferation and apoptosis, and is thought to play a role in tumour development. Previous prospective studies have shown that higher circulating concentrations of IGF-I are associated with a higher risk of cancers at specific sites, including breast and prostate. No prospective study has examined the association between circulating IGF-I concentrations and melanoma risk. A nested case-control study of 1,221 melanoma cases and 1,221 controls was performed in the European Prospective Investigation into Cancer and Nutrition cohort, a prospective cohort of 520,000 participants recruited from 10 European countries. Conditional logistic regression was used to estimate odds ratios (ORs) for incident melanoma in relation to circulating IGF-I concentrations, measured by immunoassay. Analyses were conditioned on the matching factors and further adjusted for age at blood collection, education, height, BMI, smoking status, alcohol intake, marital status, physical activity and in women only, use of menopausal hormone therapy. There was no significant association between circulating IGF-I concentration and melanoma risk (OR for highest vs lowest fifth = 0.93 [95% confidence interval [CI]: 0.71 to 1.22]). There was no significant heterogeneity in the association between IGF-I concentrations and melanoma risk when subdivided by gender, age at blood collection, BMI, height, age at diagnosis, time between blood collection and diagnosis, or by anatomical site or histological subtype of the tumour (Pheterogeneity≥0.078). We found no evidence for an association between circulating concentrations of IGF-I measured in adulthood and the risk of melanoma.
Fulltext Dietary flavonoid intake and colorectal cancer risk in the European prospective investigation into cancer and nutrition (EPIC) cohort

Zamora-Ros R, Barupal DK, Rothwell JA, Jenab M, Fedirko V, Romieu I, et al.

Int J Cancer, 2017 Apr 15;140(8):1836-1844.
PMID: 28006847 DOI: 10.1002/ijc.30582

Flavonoids have been shown to inhibit colon cancer cell proliferation in vitro and protect against colorectal carcinogenesis in animal models. However, epidemiological evidence on the potential role of flavonoid intake in colorectal cancer (CRC) development remains sparse and inconsistent. We evaluated the association between dietary intakes of total flavonoids and their subclasses and risk of development of CRC, within the European Prospective Investigation into Cancer and Nutrition (EPIC) study. A cohort of 477,312 adult men and women were recruited in 10 European countries. At baseline, dietary intakes of total flavonoids and individual subclasses were estimated using centre-specific validated dietary questionnaires and composition data from the Phenol-Explorer database. During an average of 11 years of follow-up, 4,517 new cases of primary CRC were identified, of which 2,869 were colon (proximal = 1,298 and distal = 1,266) and 1,648 rectal tumours. No association was found between total flavonoid intake and the risk of overall CRC (HR for comparison of extreme quintiles 1.05, 95% CI 0.93-1.18; p-trend = 0.58) or any CRC subtype. No association was also observed with any intake of individual flavonoid subclasses. Similar results were observed for flavonoid intake expressed as glycosides or aglycone equivalents. Intake of total flavonoids and flavonoid subclasses, as estimated from dietary questionnaires, did not show any association with risk of CRC development.
Fulltext Prediagnostic alterations in circulating bile acid profiles in the development of hepatocellular carcinoma

Stepien M, Lopez-Nogueroles M, Lahoz A, Kühn T, Perlemuter G, Voican C, et al.

Int J Cancer, 2022 Apr 15;150(8):1255-1268.
PMID: 34843121 DOI: 10.1002/ijc.33885

Bile acids (BAs) play different roles in cancer development. Some are carcinogenic and BA signaling is also involved in various metabolic, inflammatory and immune-related processes. The liver is the primary site of BA synthesis. Liver dysfunction and microbiome compositional changes, such as during hepatocellular carcinoma (HCC) development, may modulate BA metabolism increasing concentration of carcinogenic BAs. Observations from prospective cohorts are sparse. We conducted a study (233 HCC case-control pairs) nested within a large observational prospective cohort with blood samples taken at recruitment when healthy with follow-up over time for later cancer development. A targeted metabolomics method was used to quantify 17 BAs (primary/secondary/tertiary; conjugated/unconjugated) in prediagnostic plasma. Odd ratios (OR) for HCC risk associations were calculated by multivariable conditional logistic regression models. Positive HCC risk associations were observed for the molar sum of all BAs (ORdoubling = 2.30, 95% confidence intervals [CI]: 1.76-3.00), and choline- and taurine-conjugated BAs. Relative concentrations of BAs showed positive HCC risk associations for glycoholic acid and most taurine-conjugated BAs. We observe an association between increased HCC risk and higher levels of major circulating BAs, from several years prior to tumor diagnosis and after multivariable adjustment for confounders and liver functionality. Increase in BA concentration is accompanied by a shift in BA profile toward higher proportions of taurine-conjugated BAs, indicating early alterations of BA metabolism with HCC development. Future studies are needed to assess BA profiles for improved stratification of patients at high HCC risk and to determine whether supplementation with certain BAs may ameliorate liver dysfunction.
Fulltext Circulating bilirubin levels and risk of colorectal cancer: serological and Mendelian randomization analyses

Seyed Khoei N, Jenab M, Murphy N, Banbury BL, Carreras-Torres R, Viallon V, et al.

BMC Med, 2020 09 03;18(1):229.
PMID: 32878631 DOI: 10.1186/s12916-020-01703-w

BACKGROUND: Bilirubin, a byproduct of hemoglobin breakdown and purported anti-oxidant, is thought to be cancer preventive. We conducted complementary serological and Mendelian randomization (MR) analyses to investigate whether alterations in circulating levels of bilirubin are associated with risk of colorectal cancer (CRC). We decided a priori to perform analyses separately in men and women based on suggestive evidence that associations may differ by sex.
METHODS: In a case-control study nested in the European Prospective Investigation into Cancer and Nutrition (EPIC), pre-diagnostic unconjugated bilirubin (UCB, the main component of total bilirubin) concentrations were measured by high-performance liquid chromatography in plasma samples of 1386 CRC cases and their individually matched controls. Additionally, 115 single-nucleotide polymorphisms (SNPs) robustly associated (P

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