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Synergism between exposure to chemical carcinogens and infection with the hepatitis B virus (HBV) has been implicated in the high incidence of hepatocellular carcinoma. In this study we report that the HBV protein HBx, inhibits cellular DNA repair capacity in a p53-independent manner. Two alternative assays were used: the host cell reactivation assay, which measures the cell's capacity to repair DNA damage in a reporter plasmid, and unscheduled DNA synthesis, which measures the overall DNA repair capacity in damaged cells. Two p53-proficient cell lines, the hepatocellular carcinoma cell line HepG2 and liver epithelial cell line CCL13, were co-transfected with the pCMV-HBx reporter plasmid and the pCMV-CAT plasmid damaged with UVC radiation. Compared with cells transfected with control plasmid, the presence of HBx resulted in 50% inhibition of the cell's capacity to reactivate CAT activity of UVC-damaged plasmid, and 25% inhibition of unscheduled DNA synthesis in cells treated with either aflatoxin B1 epoxide or UVC radiation. Using the p53-deficient cell line Saos-2, we demonstrated that expression of HBx also resulted in diminished overall cellular DNA repair of damage induced by both aflatoxin B1 epoxide and UVC radiation, using both the host cell reactivation and unscheduled DNA synthesis assays. In summary, this study provides evidence for p53-independent regulation of DNA repair by HBx. [ABSTRACT FROM PUBLISHER]

Background: Maize is frequently contaminated by aflatoxin B 1 (AFB 1 ), an established liver carcinogen., Objective: To estimate the effect of maize and maize tortilla consumption on AFB 1 -lysine adduct (AFB 1 -lys) concentrations in middle- and older-aged adults living in south and eastern Mexico., Methods: We conducted a cross-sectional analysis in a representative sample of 915 adults aged ≥40 years living in south and eastern Mexico in 2018-19. Maize and maize tortilla intake were estimated using a food frequency questionnaire. Intake of maize tortillas made from store-purchased masa or bought in a tortilleria, from homemade masa, and from store-bought maize flour was assessed. AFB 1 -lys in serum was quantified using state-of-the-art isotope-dilution liquid chromatography-mass spectrometry. We assessed the relationship between maize and maize tortilla consumption and AFB 1 -lysine adduct by fitting linear regression models that accounted for the complex survey design., Results: Median maize intake was 307 grams/day (Quartile 1 [Q1]-Quartile 3 [Q3] = 165, 554). Maize tortillas represented 77% of total maize consumption, with a median consumption of 252 grams per day (Q1-Q2 = 120, 462). After multivariable adjustment, for every 30 grams of maize consumed (one tortilla equivalent), circulating AFB 1 -lys incremented by 2.1% (95% CI= 0.9, 3.4). For every maize tortilla consumed, the concentration of circulating AFB1-lys was 2.0% (95% CI= 0.6, 3.4) higher. The corresponding estimate for homemade masa tortilla was 2.8% (95% CI= 1.1, 4.6). The magnitude of the estimates for tortillas made from store-purchased masa or bought in a tortilleria and those made from store-bought maize flour were minimal., Conclusions: Maize and maize tortilla intake was associated to AFB1-lys concentrations. This association appears to be driven by consumption of tortillas made from homemade masa., Competing Interests: Declaration of Competing Interest ☒ The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 American Society for Nutrition. All rights reserved.)

Liver cancer, the sixth most frequently occurring cancer in the world and the third most common cause of cancer mortality, has wide geographical variation in both incidence and mortality rates. At the end of the 20th century, incidence rates began declining in some high-rate areas and increasing in some lower-rate areas. These trends were undoubtedly driven by the shifting contributions of both well-established and more novel risk factors. While notable strides have been made in combating some major risk factors, such as hepatitis B virus and hepatitis C virus, the emergence of metabolic conditions as important drivers of liver cancer risk indicates that much work remains to be done in prevention. As liver cancer is strongly associated with economic and social deprivation, research, early-diagnosis, and treatment among disadvantaged populations are of paramount importance., (©2024 American Association for Cancer Research.)

Aflatoxin B 1 (AFB 1 ) is a potent human liver carcinogen produced by certain molds, particularly Aspergillus flavus and Aspergillus parasiticus , which contaminate peanuts, corn, rice, cottonseed, and ground and tree nuts, principally in warm and humid climates. AFB 1 undergoes bioactivation in the liver to produce AFB 1 - exo -8,9-epoxide, which forms the covalently bound cationic AFB 1 - N 7-guanine (AFB 1 -N 7-Gua) DNA adduct. This adduct is unstable and undergoes base-catalyzed opening of the guanine imidazolium ring to form two ring-opened diastereomeric 8,9-dihydro-8-(2,6-diamino-4-oxo-3,4-dihydropyrimid-5-yl-formamido)-9-hydroxy-aflatoxin B 1 (AFB 1 -FapyGua) adducts. The AFB 1 formamidopyrimidine (Fapy) adducts induce G → T transversion mutations and are likely responsible for the carcinogenic effects of AFB 1 . Quantitative liquid chromatography-mass spectrometry (LC-MS) methods have shown that AFB 1 - N 7-Gua is eliminated in rodent and human urine, whereas ring-opened AFB 1 -FapyGua adducts persist in rodent liver. However, fresh frozen biopsy tissues are seldom available for biomonitoring AFB 1 DNA adducts in humans, impeding research advances in this potent liver carcinogen. In contrast, formalin-fixed paraffin-embedded (FFPE) specimens used for histopathological analysis are often accessible for molecular studies. However, ensuring nucleic acid quality presents a challenge due to incomplete reversal of formalin-mediated DNA cross-links, which can preclude accurate quantitative measurements of DNA adducts. In this study, employing ion trap or high-resolution accurate Orbitrap mass spectrometry, we demonstrate that ring-opened AFB 1 -FapyGua adducts formed in AFB 1 -exposed newborn mice are stable to the formalin fixation and DNA de-cross-linking retrieval processes. The AFB 1 -FapyGua adducts can be detected at levels comparable to those in a match of fresh frozen liver. Orbitrap MS 2 measurements can detect AFB 1 -FapyGua at a quantification limit of 4.0 adducts per 10 8 bases when only 0.8 μg of DNA is assayed on the column. Thus, our breakthrough DNA retrieval technology can be adapted to screen for AFB 1 DNA adducts in FFPE human liver specimens from cohorts at risk of this potent liver carcinogen.

We evaluated whether aflatoxin B 1 (AFB 1 ) exposure was associated with later risk of developing gallbladder cancer (GBC). We measured AFB 1 -lysine albumin adducts in baseline samples from the Shanghai Cohort Study of 18 244 men aged 45 to 64 years (recruited 1986-1989). We included 84 GBC cases with sufficient serum and 168 controls matched on age at sample collection, date of blood draw and residence. We calculated adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) for detectable vs non-detectable AFB 1 -lysine albumin adducts and gallbladder cancer. AFB 1 -lysine albumin adducts were detected in 50.0% of GBC cases, and risk of GBC was twice as high in those with detectable vs undetectable levels (OR = 2.0, 95% CI = 1.0-3.9). ORs ranged from 1.8 (95% CI = 0.75-4.3) for 0.5 to <1.75 pg/mg vs undetectable adduct levels to 2.2 (95% CI = 0.91-5.6) for >3.36 pg/mg vs undetectable, suggesting a dose-response (P trend  = .05). When restricted to cases diagnosed before the median time to diagnosis after blood draw (18.4 years), results were similar (OR = 2.2, 95% CI = 0.80-5.8) to those for the entire follow-up duration. The OR was 9.4 (95% CI = 1.7-51.1) for individuals with detectable AFB 1 -lysine albumin adducts and self-reported gallstones compared to individuals with neither. Participants with detectable AFB 1 -lysine albumin adducts at baseline had increased risk of developing GBC, replicating the previously observed association between AFB 1 exposure and providing the first evidence of temporality., (© 2023 UICC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)

Human tissue three-dimensional (3D) organoid cultures have the potential to reproduce in vitro the physiological properties and cellular architecture of the organs from which they are derived. The ability of organoid cultures derived from human stomach, liver, kidney, and colon to metabolically activate three dietary carcinogens, aflatoxin B 1 (AFB 1 ), aristolochic acid I (AAI), and 2-amino-1-methyl-6-phenylimidazo[4,5- b ]pyridine (PhIP), was investigated. In each case, the response of a target tissue (liver for AFB 1 ; kidney for AAI; colon for PhIP) was compared with that of a nontarget tissue (gastric). After treatment cell viabilities were measured, DNA damage response (DDR) was determined by Western blotting for p-p53, p21, p-CHK2, and γ-H2AX, and DNA adduct formation was quantified by mass spectrometry. Induction of the key xenobiotic-metabolizing enzymes (XMEs) CYP1A1, CYP1A2, CYP3A4, and NQO1 was assessed by qRT-PCR. We found that organoids from different tissues can activate AAI, AFB 1 , and PhIP. In some cases, this metabolic potential varied between tissues and between different cultures of the same tissue. Similarly, variations in the levels of expression of XMEs were observed. At comparable levels of cytotoxicity, organoids derived from tissues that are considered targets for these carcinogens had higher levels of adduct formation than a nontarget tissue.

Objective: To estimate the frequency of detection and levels of aflatoxin B 1 -lysine adduct (AFB 1 -lys), an important hepatocellular carcinoma (HCC) risk factor, in eastern and southern Mexico., Materials and Methods: We determined serum AFB 1 -lys using mass spectrometry in a representative sample of 952 adults (weighted n = 7,493,354) from five states (Campeche, Chiapas, Tamaulipas, Veracruz and Yucatán) in 2018. We calculated overall and subgroup-specific frequency of detection and 95% confidence intervals (95%CI) and median AFB 1 -lys levels and quartiles., Results: The overall frequency of detection of AFB 1 -lys was 91.9% (95%CI 88.6, 94.3). The median AFB 1 -lys level was 0.172 pg/μL (Q1-Q3, 0.060-0.582). Levels differed geographically (median pg/μL, 0.361 for Veracruz and 0.061 for Yucatan) and were higher among men and older individuals. Levels were almost three times higher in rural relative to urban areas (0.317 vs. 0.123 pg/μL). We observed higher AFB 1 -lys exposure in lower socioeconomic status (SES) level populations., Conclusion: AFB 1 -lys frequency of detection was very high and exposure levels were highest in Veracruz, men, rural areas, and among persons of lower SES. Understanding modifiable HCC risk factors in populations with unique epidemiological patterns could inform preventative interventions., Competing Interests: Declaration of competing interest None declared., (Copyright © 2023 Elsevier GmbH. All rights reserved.)

Background: Aflatoxin (AF) exposure is associated with child growth faltering in cross-sectional studies, with limited findings from longitudinal studies., Objectives: To evaluate the relationship between maternal AF B 1 -lysine adduct concentration, child AF B 1 -lysine adduct concentration, and child growth in the first 30 mo of life., Methods: AF B 1 -lysine adduct was measured in mother-child dyad plasma samples using isotope dilution mass spectrometry. Using linear regression, we assessed the relationship between AF B 1 -lysine adduct concentration and child weight, height, and head and mid-upper arm circumferences at 1 wk, 6, 12, 18, 24, and 30 mo of age., Results: In adjusted models, maternal prenatal AF B 1 -lysine adduct (pg/μL) was positively associated with newborn anthropometric outcomes; largest beta coefficients for associations between standardized values were for newborn weight-for-age z -score [β = 0.13; 95% confidence interval (CI): 0.02, 0.24; P < 0.05 and β = 0.11; 95% CI: 0.00, 0.22; P < 0.05 for second and third trimester AF, respectively]. Child AF B 1 -lysine adduct (pg/μL) at 6 mo was negatively associated with head circumference-for-age z -score at 6, 18, 24, and 30 mo, with beta coefficients ranging from β = -0.15; 95% CI: -0.28, -0.02 to β = -0.17; 95% CI: -0.31, -0.03; P < 0.05); 18-mo AF was negatively associated with anthropometric outcomes at 18, 24, and 30 mo, most consistently with length-for-age z -score (β = -0.18; 95% CI: -0.32, -0.04, β = -0.21; 95% CI: -0.35, -0.07, β = -0.18; 95% CI: -0.32, -0.03 at 18, 24 and 30 mo, respectively)., Conclusions: Child AF exposure was associated with impaired child growth, but maternal AF exposure was not. Exposure during infancy was linked to persistent deficit in head circumference, implying reduced brain size lasting beyond the age of 2 years. Exposure at 18 mo was linked to persistent linear growth deficit. Further research should elucidate mechanisms through which AF affects child growth., Competing Interests: ☒ The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Assessing personal exposure to environmental toxicants is a critical challenge for predicting disease risk. Previously, using human serum albumin (HSA)-based biomonitoring, we reported dosimetric relationships between adducts at HSA Cys 34 and ambient air pollutant levels (Smith et al., Chem. Res. Toxicol . 2021 , 34 , 1183). These results provided the foundation to explore modifications at other sites in HSA to reveal novel adducts of complex exposures. Thus, the Pan-Protein Adductomics (PPA) technology reported here is the next step toward an unbiased, comprehensive characterization of the HSA adductome. The PPA workflow requires <2 μL serum/plasma and uses nanoflow-liquid chromatography, gas-phase fractionation, and overlapping-window data-independent acquisition high-resolution tandem mass spectrometry. PPA analysis of albumin from nonsmoking women exposed to high levels of air pollution uncovered 68 unique location-specific modifications (LSMs) across 21 HSA residues. While nearly half were located at Cys 34 (33 LSMs), 35 were detected on other residues, including Lys, His, Tyr, Ser, Met, and Arg. HSA adduct relative abundances spanned a ∼400 000-fold range and included putative products of exogenous (SO 2 , benzene, phycoerythrobilin) and endogenous (oxidation, lipid peroxidation, glycation, carbamylation) origin, as well as 24 modifications without annotations. PPA quantification revealed statistically significant changes in LSM levels across the 84 days of monitoring (∼3 HSA lifetimes) in the following putative adducts: Cys 34 trioxidation, β-methylthiolation, benzaldehyde, and benzene diol epoxide; Met 329 oxidation; Arg 145 dioxidation; and unannotated Cys 34 and His 146 adducts. Notably, the PPA workflow can be extended to any protein. Pan-Protein Adductomics is a novel and powerful strategy for untargeted global exploration of protein modifications.

Enteropathy is a pathophysiological condition characterized by decreased intestinal barrier function and absorption. Past studies have hypothesized that mycotoxins might impair children's growth by causing intestinal enteropathy, including interactions between mycotoxins and pathogens. We investigated the association of two mycotoxins, aflatoxin B 1 (AFB 1 ) and fumonisin B 1 (FB 1 ), independently and in conjunction with microbial pathogens, with fecal biomarkers of environmental enteropathy in children. As part of a larger MAL-ED study, 196 children were recruited in Haydom, Tanzania, and followed for the first 36 months of life. The gut inflammation biomarkers myeloperoxidase (MPO), neopterin (NEO), and alpha-1-antitrypsin (A1AT) were analyzed in stool samples at 24 months; with mean concentrations 5332.5 ng/L MPO, 807.2 nmol/L NEO, and 0.18 mg/g A1AT. Forty-eight children were measured for AFB 1 -lys, with a mean of 5.30 (95% CI: 3.93-6.66) pg/mg albumin; and 87 were measured for FB 1 , with a mean of 1.25 (95% CI: 0.72-1.76) ng/ml urine. Although the pathogens adenovirus and Campylobacter were associated with A1AT (p = 0.049) and NEO (p = 0.004), respectively, no association was observed between aflatoxin (MPO, p = 0.30; NEO, p = 0.08; A1AT, p = 0.24) or fumonisin (MPO, p = 0.38; NEO, p = 0.65; A1AT, p = 0.20) exposure and any gut inflammation biomarkers; nor were interactive effects found between mycotoxins and pathogens in contributing to intestinal enteropathy in this cohort. Although further studies are needed to confirm these results, it is possible that mycotoxins contribute to child growth impairment via mechanisms other than disrupting children's intestinal function., (© 2022 The Authors. Risk Analysis published by Wiley Periodicals LLC on behalf of Society for Risk Analysis.)

Background: Non-alcoholic fatty liver disease (NAFLD) is a major liver disease worldwide. Bile acid dysregulation may be a key feature in its pathogenesis and progression., Aims: To characterise the relationship between bile acid levels and NAFLD at the population level METHODS: We conducted a cross-sectional study in Guatemala in 2016 to examine the prevalence of NAFLD. Participants (n = 415) completed questionnaires, donated blood samples and had a brief medical exam. NAFLD was determined by calculation of the fatty liver index. The levels of 15 circulating bile acids were determined by LC-MS/MS. Adjusted prevalence odds ratios (POR adj ) and 95% CI were calculated to examine the relationships between bile acid levels (in tertiles) and NAFLD., Results: Persons with NAFLD had significantly higher levels of the conjugated primary bile acids glycocholic acid (GCA) (POR adj T3 vs T1  = 1.85), taurocholic acid (TCA) (POR adj T3 vs T1  = 2.45) and taurochenodeoxycholic acid (TCDCA) (POR adj T3 vs T1  = 2.10), as well as significantly higher levels the unconjugated secondary bile acid, deoxycholic acid (DCA) (POR adj T3 vs T1  = 1.78) and its conjugated form, taurodeoxycholic acid (TDCA) (POR adj T3 vs T1  = 1.81)., Conclusions: The bile acid levels of persons with and without NAFLD differed significantly. Among persons with NAFLD, higher levels of the conjugated forms of CA (i.e. GCA, TCA) and the secondary bile acids that derive from CA (i.e. DCA, TDCA) may indicate there is hepatic overproduction of CA, which may affect the liver via aberrant signalling mediated by the bile acids., (© 2022 John Wiley & Sons Ltd.)

The assessment of aflatoxin B 1 (AFB 1 ) exposure using isotope-dilution liquid chromatography-mass spectrometry (LCMS) of AFB 1 -lysine adducts in human serum albumin (HSA) has proven to be a highly productive strategy for the biomonitoring of AFB 1 exposure. To compare samples across different individuals and settings, the conventional practice has involved the normalization of raw AFB 1 -lysine adduct concentrations (e.g., pg/mL serum or plasma) to the total circulating HSA concentration (e.g., pg/mg HSA). It is hypothesized that this practice corrects for technical error, between-person variance in HSA synthesis or AFB 1 metabolism, and other factors. However, the validity of this hypothesis has been largely unexamined by empirical analysis. The objective of this work was to test the concept that HSA normalization of AFB 1 -lysine adduct concentrations effectively adjusts for biological and technical variance and improves AFB 1 internal dose estimates. Using data from AFB 1 -lysine and HSA measurements in 763 subjects, in combination with regression and Monte Carlo simulation techniques, we found that HSA accounts for essentially none of the between-person variance in HSA-normalized (R 2 = 0.04) or raw AFB 1 -lysine measurements (R 2 = 0.0001), and that HSA normalization of AFB 1 -lysine levels with empirical HSA values does not reduce measurement error any better than does the use of simulated data ( n = 20,000). These findings were robust across diverse populations (Guatemala, China, Chile), AFB 1 exposures (10 5 range), HSA assays (dye-binding and immunoassay), and disease states (healthy, gallstones, and gallbladder cancer). HSA normalization results in arithmetic transformation with the addition of technical error from the measurement of HSA. Combined with the added analysis time, cost, and sample consumption, these results suggest that it may be prudent to abandon the practice of normalizing adducts to HSA concentration when measuring any HSA adducts-not only AFB 1 -lys adducts-when using LCMS in serum/plasma.

Background and Aims: Metabolic conditions such as obesity, type 2 diabetes, metabolic syndrome, and nonalcoholic fatty liver disease (NAFLD) are highly prevalent in Guatemala and increase the risk for a number of disorders, including hepatocellular carcinoma (HCC). Aflatoxin B 1 (AFB 1 ) levels are also notably elevated in the population and are known to be associated with HCC risk. Whether AFB 1 also contributes to the high prevalence of the metabolic disorders has not been previously examined. Therefore, the purpose of this study was to assess the association between AFB 1 and the metabolic conditions., Methods: Four-hundred twenty-three individuals were included in the study, in which AFB 1 -albumin adduct levels were measured in sera. Metabolic conditions included diabetes, obesity, central obesity, metabolic syndrome, and NAFLD. Crude and adjusted prevalence odds ratios (PORs) and 95% confidence intervals (95% CI) were estimated for the associations between the metabolic conditions and AFB 1 -albumin adduct levels categorized into quartiles., Results: The study found a significant association between AFB 1 -albumin adduct levels and diabetes (Q4 vs Q1 POR = 3.74, 95%CI: 1.71-8.19; P-trend .003). No associations were observed between AFB 1 -albumin adduct levels and the other conditions., Conclusions: As diabetes is the metabolic condition most consistently linked to HCC, the possible association between AFB 1 exposure and diabetes may be of public health importance. Further studies are warranted to replicate the findings and examine potential mechanisms., Competing Interests: The authors declare no potential conflict of interest., (© 2022 The Authors. Health Science Reports published by Wiley Periodicals LLC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.)

Background: In utero or early-life exposure to aflatoxin, which contaminates staple crops in disadvantaged settings, may compromise pregnancy and infant outcomes, but investigations into the extent, persistence, and determinants of aflatoxin exposure at these life stages have lacked longitudinal data collection and broad geographic representation., Objectives: Aflatoxin exposure and selected determinants thereof were characterized in mother-child dyads with serial plasma/serum samples in prenatal, perinatal, and early life in Malawi and Bangladesh., Methods: Circulating aflatoxin B 1 (AFB 1 )-lysine albumin adducts were measured in dyads from Bangladesh ( n  = 573; maternal first and third trimester, 3 mo postpartum, cord blood, infant 24 mo) and Malawi ( n  = 255; maternal second and third trimester, 6 mo postpartum, infant 6 and 18 mo) with isotope dilution mass spectrometry. We examined AFB 1 -lysine adduct magnitude, persistence, seasonality, and associations with infant feeding, and estimated daily AFB 1 intake., Results: Maternal AFB 1 -lysine was higher in Malawi (98% detectable; median: 0.469, IQR: 0.225-1.027 pg/µL) than in Bangladesh (59%; 0.030, nondetectable [nd]-0.077 pg/µL). Although estimated dietary exposure in Malawi was temporally stable (648 ng AFB 1 /day), estimated intake in Bangladesh was reduced by 94% between rainy and winter seasons (98 to 6 ng/day). AFB 1 -lysine was low in cord blood from Bangladesh (15% detectable; 0.045, 0.031-0.088 pg/µL among detectable) and in Malawian infants at 6 mo of age (0.072, nd-0.236 pg/µL), but reached maternal concentrations by 18 or 24 mo (Bangladesh: 0.034, nd-0.063 pg/µL; Malawi: 0.370, 0.195-0.964 pg/µL). In Malawian infants, exclusive breastfeeding at 3 mo was associated with 58% lower AFB 1 -lysine concentrations at 6 mo compared with other feeding modes ( P  = 0.010)., Conclusions: Among pregnant women, aflatoxin exposure was persistently high in Malawi, while lower and seasonal in Bangladesh. Infants were partially protected from exposure in utero and with exclusive breastfeeding, but exposures reached adult levels by 18-24 mo of age. The Bangladesh and Malawi trials are registered at clinicaltrials.gov as NCT00860470 and NCT01239693., (© The Author(s) 2022. Published by Oxford University Press on behalf of the American Society for Nutrition.)

HIV transmission risk is dependent on the infectivity of the HIV+ partner and personal susceptibility risk factors of the HIV- partner. The mucosal barrier, as the internal gatekeeper between environment and self, concentrates and modulates the internalization of ingested pathogens and pollutants. In this review, we summarize the localized effects of HIV and dietary toxin aflatoxin B1 (AFB 1 ), a common pollutant in high HIV burden regions, e.g., at the mucosal barrier, and evidence for pollutant-viral interactions. We compiled literature on HIV and AFB 1 geographic occurrences, mechanisms of action, related co-exposures, personal risk factors, and HIV key determinants of health. AFB 1 exposure and HIV sexual transmission hotspots geographically co-localize in many low-income countries. AFB 1 distributes to sexual mucosal tissues generating inflammation, microbiome changes and a reduction of mucosal barrier integrity, effects that are risk factors for increasing HIV susceptibility. AFB 1 exposure has a positive correlation to HIV viral load, a risk factor for increasing the infectivity of the HIV+ partner. The AFB 1 exposure and metabolism generates inflammation that recruits HIV susceptible cells and generates chemokine/cytokine activation in tissues exposed to HIV. Although circumstantial, the available evidence makes a compelling case for studies of AFB 1 exposure as a risk factor for HIV transmission, and a modifiable new component for combination HIV prevention efforts.

Objective: Chronic aflatoxin exposure has been associated with childhood stunting (length-for-age/height-for-age < -2 sd), while data lacks for Bangladesh, a country with substantial burden of childhood stunting. This paper examined the association between aflatoxin exposure and childhood stunting in a slum setting of Dhaka city., Design: In this MAL-ED aflatoxin birth cohort study, plasma samples were assayed for aflatoxin B1-lysine adduct (AFB1-lys) by MS at 7, 15, 24 and 36 months of age for 208, 196, 173 and 167 children to assess chronic aflatoxin exposure. Relationship between aflatoxin exposure and anthropometric measures was examined by mixed-effects logistic regression models., Setting and Participants: The study was conducted in Mirpur, Dhaka, where children were followed from birth to 36 months., Results: Prevalence of stunting increased from 21 % at 7 months to 49 % at 36 months of age. Mean AFB1-lys concentrations at 7, 15, 24 and 36 months were 1·30 (range 0·09-5·79), 1·52 (range 0·06-6·35), 3·43 (range 0·15-65·60) and 3·70 (range 0·09-126·54) pg/mg albumin, respectively, and the percentage of children with detectable AFB1-lys was 10, 21, 18 and 62 %, respectively. No association was observed between aflatoxin exposure and stunting in multivariable analyses. Factors associated with childhood stunting were age, low birth weight, maternal height, stool myeloperoxidase and number of people sleeping in one room., Conclusions: A relatively lower exposure to aflatoxin may not influence the linear growth of children. This finding indicates a threshold level of exposure for linear growth deficit and further investigation in other areas where higher concentrations of aflatoxin exposure exist.

Outdoor air pollution, a spatially and temporally complex mixture, is a human carcinogen. However, ambient measurements may not reflect subject-level exposures, personal monitors do not assess internal dose, and spot assessments of urinary biomarkers may not recapitulate chronic exposures. Nucleophilic sites in serum albumin-particularly the free thiol at Cys 34 -form adducts with electrophiles. Due to the 4-week lifetime of albumin in circulation, accumulating adducts can serve as intermediate- to long-residence biomarkers of chronic exposure and implicate potential biological effects. Employing nanoflow liquid chromatography-high-resolution mass spectrometry (nLC-HRMS) and parallel reaction monitoring (PRM), we have developed and validated a novel targeted albumin adductomics platform capable of simultaneously monitoring dozens of Cys 34 adducts per sample in only 2.5 μL of serum, with on-column limits of detection in the low-femtomolar range. Using this platform, we characterized the magnitude and impact of ambient outdoor air pollution exposures with three repeated measurements over 84 days in n = 26 nonsmoking women ( n = 78 total samples) from Qidong, China, an area with a rising burden of lung cancer incidence. In concordance with seasonally rising ambient concentrations of NO 2 , SO 2 , and PM 10 measured at stationary monitors, we observed elevations in concentrations of Cys 34 adducts of benzoquinone ( p < 0.05), benzene diol epoxide (BDE; p < 0.05), crotonaldehyde ( p < 0.01), and oxidation ( p < 0.001). Regression analysis revealed significant elevations in oxidation and BDE adduct concentrations of 300% to nearly 700% per doubling of ambient airborne pollutant levels ( p < 0.05). Notably, the ratio of irreversibly oxidized to reduced Cys 34 rose more than 3-fold during the 84-day period, revealing a dramatic perturbation of serum redox balance and potentially serving as a portent of increased pollution-related mortality risk. Our targeted albumin adductomics assay represents a novel and flexible approach for sensitive and multiplexed internal dosimetry of environmental exposures, providing a new strategy for personalized biomonitoring and prevention.

Background and Aims: Liver cancer is one of the most dominant malignant tumors in the world. The trends of liver cancer mortality over the past six decades have been tracked in the epidemic region of Qidong, China. Using epidemiological tools, we explore the dynamic changes in age-standardized rates to characterize important aspects of liver cancer etiology and prevention., Methods: Mortality data of liver cancer in Qidong from 1958 to 1971 (death retrospective survey) and from 1972 to 2017 (cancer registration) were tabulated for the crude rate (CR), and age-standardized rate and age-birth cohorts. The average annual percentage change was calculated by the Joinpoint Regression Program., Results: The natural death rate during 1958-2017 decreased from 9‰ to 5.4‰ and then increased to 8‰ as the population aged; cancer mortality rates rose continuously from 57/10 5 to 240/10 5 . Liver cancer mortality increased from 20/10 5 to 80/10 5 , and then dropped to less than 52/10 5 in 2017. Liver cancer deaths in 1972-2017 accounted for 30.53% of all cancers, with a CR of 60.48/10 5 , age-standardized rate China (ASRC) of 34.78/10 5 , and ASRW (world) of 45.71/10 5 . Other key features were the CR for males and females of 91.86/10 5 and 29.92/10 5 , respectively, with a sex ratio of 3.07:1. Period analysis showed that the ASRs for mortality of the age groups under 54 years old had a significant decreasing trend. Importantly, birth cohort analysis showed that the mortality rate of liver cancer in 40-44, 35-39, 30-34, 25-29, 20-24, 15-19 years cohort decreased considerably, but the rates in 70-74, and 75+ increased., Conclusions: The crude mortality rate of liver cancer in Qidong has experienced trends from lower to higher levels, and from continued increase at a high plateau to most recently a gradual decline, and a change greatest in younger people. Many years of comprehensive prevention and intervention measures have influenced the decline of the liver cancer epidemic in this area. The reduction of intake levels of aflatoxin might be one of the most significant factors as evidenced by the dramatic decline of exposure biomarkers in this population during the past three decades., Competing Interests: The authors declare there are no competing interests., (©2021 Chen et al.)

During the 60 years since the first scientific reports about a relation between aflatoxin exposure and adverse health consequences, both in animals and humans, there has been a remarkable number of basic, clinical and population science studies characterizing the impact of this mycotoxin on diseases such as liver cancer. Many of these human investigations to date have focused on populations residing in Asia and Africa due to the high incidence of liver cancer and high exposures to aflatoxin. These studies formed the basis for the International Agency for Research on Cancer to classify the aflatoxins as Group 1 known human carcinogens. In addition, aflatoxin contamination levels have been used in international commodity trade to set the price of various staples such as maize and groundnuts. While there have been many case-control and prospective cohort studies of liver cancer risk over the years there have been remarkably few investigations focused on liver cancer in Latin America. Our interdisciplinary and multiple institutional collaborative has been developing a long-term strategy to characterize the role of aflatoxin and other mycotoxins as health risk factors in Guatemala and neighboring countries. This paper summarizes a number of the investigations to date and provides a roadmap of our strategies for the near term to discern the emergent etiology of liver cancer in this region. With these data in hand public health-based prevention strategies could be strategically implemented and conducted to lower the impact of these mycotoxins on human health., Competing Interests: Conflict of Interest: The authors have no conflicts of interest to disclose.

Background: Previous studies have suggested an association between Helicobacter pylori (H pylori) and nonalcoholic fatty liver disease (NAFLD). The aim of the current study was to examine the association in Guatemala, a region with elevated prevalences of both H pylori and NAFLD. Associations between H pylori and other metabolic conditions were also examined, as were associations between H hepaticus and H bilis and the metabolic conditions., Materials & Methods: The analysis included 424 participants from a cross-sectional study in Guatemala. H pylori seropositivity was defined as positivity for ≥ 4 antigens. Seropositivities for H bilis and H hepaticus were defined as positivity for ≥ 2 antigens. NAFLD was estimated using the Fatty Liver Index and the Hepatic Steatosis Index. Other conditions examined were obesity, central obesity, hypercholesterolemia, low HDL, diabetes and metabolic syndrome (MetSyn). Prevalence odds ratios (POR) and 95% confidence intervals (CIs) were estimated., Results: No overall associations between H pylori,H hepaticus, or H bilis and NAFLD or related metabolic conditions were found. Seropositivity for H pylori antigens CagA and VacA and H hepaticus antigen HH0713 was each significantly associated with NAFLD, however. In addition, associations were observed between the H pylori antigens HyuA, HP1564, and UreA and specified metabolic conditions., Conclusions: While no overall associations between H pylori or Helicobacter species with NAFLD or related conditions were observed, some selected Helicobacter spp. antigens were associated with NAFLD. Further research is warranted to examine whether H. species are associated with any metabolic condition., (© 2020 John Wiley & Sons Ltd.)

Objective: In Guatemala, cirrhosis is among the 10 leading causes of death, and mortality rates have increased lately. The reasons for this heavy burden of disease are not clear as the prevalence of prominent risk factors, such as hepatitis B virus, hepatitis C virus and heavy alcohol consumption, appears to be low. Aflatoxin B 1 (AFB 1 ) exposure, however, appears to be high, and thus could be associated with the high burden of cirrhosis. Whether AFB 1 increases the risk of cirrhosis in the absence of viral infection, however, is not clear., Design: Cirrhosis cases (n=100) from two major referral hospitals in Guatemala City were compared with controls (n=200) from a cross-sectional study. Logistic regression was used to estimate the ORs and 95% CIs of cirrhosis and quintiles of AFB 1 in crude and adjusted models. A sex-stratified analysis was also conducted., Results: The median AFB 1 level was significantly higher among the cases (11.4 pg/mg) than controls (5.11 pg/mg). In logistic regression analyses, higher levels of AFB 1 was associated with cirrhosis (quintile 5 vs quintile 1, OR: 11.55; 95% CI 4.05 to 32.89). No attenuation was observed with adjustment by sex, ethnicity, hepatitis B virus status, and heavy alcohol consumption. A significantly increasing trend in association was observed in both models (p trend <0.01). Additionally, the cirrhosis-AFB 1 association was more prominent among men., Conclusions: The current study found a significant positive association between AFB 1 exposure and cirrhosis. Mitigation of AFB 1 exposure and a better understanding of additional risk factors may be important to reduce the burden of cirrhosis in Guatemala., Competing Interests: Competing interests: None declared., (Re-use permitted under CC BY. Published by BMJ.)

Background and Aims: Guatemala has the highest incidence of hepatocellular carcinoma (HCC) in the Western hemisphere. The major risk factors in Guatemala are not well characterized, but the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) appears to be low, while the prevalence of aflatoxin (AFB 1 ) exposure appears to be high. To examine whether AFB 1 may contribute to the elevated incidence of HCC in Guatemala, this study examined the frequency of the AFB 1 -signature mutation in the TP53 gene (R249S) as well as other somatic mutations. In addition, we assessed whether the frequency of the TP53 mutation differed by sex., Methods: Formalin-fixed, paraffin-embedded (FFPE) HCC tissues were obtained from three hospitals in Guatemala City between 2016 and 2017. In addition, tumor tissues preserved in RNAlater were also obtained. Sociodemographic and clinical information including HBV and HCV status were collected. Targeted sequencing of TP53 was performed in the FFPE samples, and a panel of 253 cancer-related genes was sequenced in the RNAlater samples., Results: Ninety-one FFPE tissues were examined, from 52 men and 39 women. Median (IQR) age at diagnosis was 62 (51-70). Among those with known HBV and HCV status, two were HBV+ and three were HCV+. Overall, 47% of the HCCs had a TP53 mutation. The AFB 1 -signature R249S mutation was present in 24%. No overlap between the R249S mutation and HBV+ was observed in this cohort. Among 18 RNAlater samples examined, 44% had any TP53 mutation and 33% had the R249S mutation. Other somatic mutations were identified in known HCC driver genes., Conclusions: The presence of the TP53 R249S mutation in the samples studied suggests that AFB 1 may contribute to the high incidence of HCC in Guatemala. The proportion of HBV+ tumors was low, suggesting that AFB 1 may be associated with HCC in the absence of concomitant HBV infection. Further investigation of AFB 1 and other risk factors for HCC in Guatemala is warranted., Competing Interests: The authors declare no potential conflicts of interest., (© 2020 The Authors. Health Science Reports published by Wiley Periodicals, Inc.)

Exploration of animal models leads to discoveries that can reveal candidate biomarkers for translation to human populations. Herein, a model of hepatocarcinogenesis and protection was used in which rats treated with aflatoxin (AFB 1 ) daily for 28 days (200 µg/kg BW) developed tumors compared with rats completely protected from tumors by concurrent administration of the chemoprotective agent, 1-[2-cyano-3-,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole (CDDO-Im). Differential expression of miRNAs in tumors (AFB 1 ) and nontumor (AFB 1  + CDDO-Im) bearing livers and their levels in sera over the life-course of the animals was determined. miRNA transcriptome analysis identified 17 miRNAs significantly upregulated at greater than five-fold in the tumors. The ten most dysregulated miRNAs judged by fold-change and biological significance were selected for further study, including liver-specific miR-122-5p. Validation of sequencing results by real-time PCR confirmed the upregulation of the majority of these miRNAs in tumors, including miR-182, as well as miR-224-5p as the most dysregulated of these miRNAs (over 400-fold). The longitudinal analysis of levels of miR-182 in sera demonstrated significant and persistent increases (5.13-fold; 95% CI: 4.59-5.70). The increase in miR-182 was detected months before any clinical symptoms were present in the animals. By the terminal time point of the study, in addition to elevated levels of serum miR-182, serum miR-122-5p was also found to be increased (>1.5-fold) in animals that developed hepatocarcinomas. Thus, using the data from an unbiased discovery approach of the tissue findings, serum miR-182 was found to track across the complex, multistage process of hepatocarcinogenesis opening an opportunity for translation to human populations., (© 2019 Wiley Periodicals, Inc.)

Objective: Persistent organic pollutants (POPs) are lipophilic environmental toxicants that accumulate in adipose tissue. Weight loss leads to mobilization and increased redistribution of these toxicants. Many are obesogens and endocrine disruptors. Increased exposure could pose long-term health risks. The study objective was to measure the changes in serum concentrations of lipophilic POPs during significant weight loss., Methods: This study enrolled 27 patients at a university hospital in a longitudinal, 6-month, observational study examining changes in POP blood levels after bariatric surgery. The primary outcome was the changes in the concentrations of 24 polychlorinated biphenyls (PCBs), 9 organochlorine pesticides (OCPs), 11 polybrominated diphenyl ethers, 2,2',4,4',5,5'-hexabromobiphenyl, and 4 perfluorochemicals (PFCs)., Results: Older adults (those born before 1976) had baseline levels of PCBs, OCPs, and PFCs that were two- to fivefold higher than younger adults (those born after 1976). Older adults had greater increases in PCBs, OCPs, and polybrominated diphenyl ethers associated with weight loss. Conversely, younger adults had greater increases in PFCs associated with weight loss. On average, blood POP levels increased as weight loss occurred., Conclusions: Although weight loss is considered beneficial, the release and redistribution of POPs to other lipid-rich organs such as the brain, kidneys, and liver warrant further investigation. Interventions should be considered to limit organ exposure to POPs when weight loss interventions are planned., (© 2019 The Obesity Society.)

Dietary exposure to aflatoxin is implicated in growth faltering of children. Despite the high burden of childhood stunting in urban Bangladesh, there are no data on long-term exposure to aflatoxin. This study aimed to explore aflatoxin exposure levels in a group of children followed longitudinally. The current study used data and biospecimens collected during 2010-2014 as part of the MAL-ED birth cohort study in an urban slum of Mirpur, Dhaka where children were followed from birth to 36 months. AFB1-lysine adduct concentrations were determined by isotope dilution mass spectrometry from plasma samples collected at 7, 15, 24, and 36 months of age. The limit of detection was 0.5 pg of AFB1-lys/mg albumin. In 744 plasma samples, the geometric mean of AFB1-lysine/mg albumin was 1.07 pg (range 0.04-123.5 pg/mg albumin). The proportion of children with detectable aflatoxin exposure was 10.1, 20.9, 17.9, and 61.7% for 7, 15, 24, and 36 months, respectively. Reduction in breastfeeding prevalence (80% at 24 months vs. 38% in 36 months) corresponded with the high-level detection of AFB1-lysine at the age of 36 months. AFB1-lysine concentrations were the highest at the end of monsoon. This study reveals that 62% of children in slum settlement were exposed to aflatoxin by the end of the third year of life. High aflatoxin exposure was detected at the end of rainy season and with the introduction of family food. These findings suggest interventions to ameliorate the problem of chronic aflatoxin exposure including childhood stunting.

Hepatocellular carcinoma (HCC) has emerged as a major cause of cancer deaths globally. The landscape of systemic therapy has recently changed, with six additional systemic agents either approved or awaiting approval for advanced stage HCC. While these agents have the potential to improve outcomes, a survival increase of 2-5 months remains poor and falls short of what has been achieved in many other solid tumor types. The roles of genomics, underlying cirrhosis, and optimal use of treatment strategies that include radiation, liver transplantation, and surgery remain unanswered. Here, we discuss new treatment opportunities, controversies, and future directions in managing HCC., (©2019 American Association for Cancer Research.)

Maternal systemic inflammation during pregnancy may restrict embryo-fetal growth, but the extent of this effect remains poorly established in undernourished populations. In a cohort of 653 maternal-newborn dyads participating in a multi-armed, micronutrient supplementation trial in southern Nepal, we investigated associations between maternal inflammation, assessed by serum α1-acid glycoprotein and C-reactive protein, in the first and third trimesters of pregnancy, and newborn weight, length and head and chest circumferences. Median (IQR) maternal concentrations in α1-acid glycoprotein and C-reactive protein in the first and third trimesters were 0.65 (0.53-0.76) and 0.40 (0.33-0.50) g/l, and 0.56 (0.25-1.54) and 1.07 (0.43-2.32) mg/l, respectively. α1-acid glycoprotein was inversely associated with birth size: weight, length, head circumference and chest circumference were lower by 116 g (P = 2.3 × 10-6), and 0.45 (P = 3.1 × 10-5), 0.18 (P = 0.0191) and 0.48 (P = 1.7 × 10-7) cm, respectively, per 50% increase in α1-acid glycoprotein averaged across both trimesters. Adjustment for maternal age, parity, gestational age, nutritional and socio-economic status and daily micronutrient supplementation failed to alter any association. Serum C-reactive protein concentration was largely unassociated with newborn size. In rural Nepal, birth size was inversely associated with low-grade, chronic inflammation during pregnancy as indicated by serum α1-acid glycoprotein.

Background: To evaluate the association of liver fibrosis scores with PSA level among U.S. adult men overall and by race/ethnicity., Methods: Data from the National Health and Nutrition Examination Survey (NHANES), 2001-2010, were used. Males ages ≥40 years without a prostate cancer diagnosis and who had serum PSA, liver enzymes, albumin, and platelet counts measured as part of NHANES protocol were included. Liver fibrosis was measured using three scores: aspartate aminotransferase to platelet ratio index (APRI), fibrosis 4 index (FIB-4), and NAFLD fibrosis score (NFS). We assessed overall and race/ethnicity-stratified geometric mean PSA by fibrosis score using predictive margins by linear regression, and the association of abnormal fibrosis scores (APRI > 1, FIB-4 > 2.67, NFS > 0.676) and elevated PSA (>4 ng/mL) by logistic regression., Results: A total of 6,705 men were included. Abnormal liver fibrosis scores were present in 2.1% (APRI), 3.6% (FIB-4), and 5.6% (NFS). Men with higher fibrosis scores had lower geometric mean PSA (all P trend < 0.02). Men with abnormal APRI had a lower odds of PSA > 4 ng/mL [adjusted OR (aOR) = 0.33; 95% confidence interval (CI), 0.11-0.96]. Compared with men with 0 abnormal scores, those with 2 or 3 abnormal fibrosis scores had a lower odds of PSA > 4 ng/mL (aOR = 0.55; 95% CI, 0.33-0.91). The patterns were similar by race/ethnicity., Conclusions: Men of all race/ethnicities with higher liver fibrosis scores had lower serum PSA, and men with advanced fibrosis scores had a lower odds of an elevated PSA., Impact: These findings support further research to inform the likelihood of delay in prostate cancer detection in men with abnormal liver function., (©2019 American Association for Cancer Research.)

Impact Statement: There is a rapidly occurring, dynamic change, in the causes of morbidity and mortality in different populations across the globe. More people today are being diagnosed and treated for chronic diseases such as cancer, cardiovascular disease, and diabetes than ever before. Environmental exposures across the lifespan have a profound impact on the outcomes of these chronic diseases. Further, there are more people living today who have survived their therapy from these diagnoses and who are now differentially susceptible to environmental exposures. Collectively, this poses both the challenge and opportunity to the experimental biology and medicine community to build new models that reflect this changing human situation. The extraordinary advances in our understanding of the biology of disease provide extraordinary insights for both therapeutic and prevention strategies. Multidisciplinary teams including biological, physical, engineering and social and behavioral scientists will be needed to address this problem over the next several decades.

Aflatoxin B 1 (AFB 1 ) is a known human hepatocarcinogen and a recent study reported elevated AFB 1 levels, measured by serum albumin biomarkers, among Guatemalan adults. While AFB 1 can contaminate a variety of foodstuffs, including maize, Guatemala's main dietary staple, the relationship of maize intake to serum AFB 1 -albumin adducts levels in Guatemala has not been previously examined. As a result, a cross-sectional study was conducted among 461 Guatemalan adults living in five geographically distinct departments of the country. Participants provided a serum sample and completed a semi-quantitative food frequency questionnaire and a sociodemographic questionnaire. Multiple linear regression analysis was used to estimate the least square means (LSQ) and 95% confidence intervals (95% CI) of log-transformed AFB 1 -albumin adducts by quintiles of maize consumption in crude and adjusted models. Additionally, analyses of tortilla consumption and levels of maize processing were conducted. The median maize intake was 344.3 g per day [Interquartile Range (IQR): 252.2, 500.8], and the median serum AFB 1 -albumin adduct level was 8.4 pg/mg albumin (IQR: 3.8, 22.3). In adjusted analyses, there was no association between overall maize consumption and serum AFB 1 -albumin levels. However, there was a statistically significant association between tortilla consumption and AFB 1 -albumin levels (p trend  = 0.01). The LSM of AFB 1 -albumin was higher in the highest quintile of tortilla consumption compared to the lowest quintile [LSM:9.03 95%CI: 7.03,11.70 vs 6.23, 95%CI: 4.95,8.17, respectively]. These findings indicate that tortilla may be an important source of AFB 1 exposure in the Guatemalan population. Therefore, efforts to control or mitigate AFB 1 levels in contaminated maize used for tortillas may reduce overall exposure in this population.

Sulforaphane is a redox-active natural product present in cruciferous vegetables like broccoli. Broccoli sprout-derived products are promising agents for the prevention of oxidative stress-related diseases, but some have long been suspected of thyroidal toxicity. Recent findings also raise the possibility that long-term exposure to sulforaphane, or to other natural substances or drugs that modulate the activity of the transcription factor Nrf2 (NFE2-related factor 2) may lead to thyroid dysfunction or thyroid autoimmune disease, questioning the safety of trials with sulforaphane-containing products. Previous studies addressing possible effects of sulforaphane-related compounds from natural product extracts on the thyroid were quite short and/or inconsistent. To investigate whether long-term exposure to a beverage enriched with sulforaphane and its precursor glucoraphanin may affect thyroid function, we analyzed biochemical measures of thyroid function and thyroid autoimmunity in 45 female participants in a randomized clinical trial at baseline and after 84 days of beverage administration. Serum levels of thyroid-stimulating hormone, free thyroxine and thyroglobulin were not affected by the treatment, and neither was the thyroid autoimmunity status of participants. These results provide evidence in favor of the safety of chemoprevention strategies that target the activation of Nrf2 to protect against environmental exposures and other oxidative stress-related pathologies., (Copyright © 2019. Published by Elsevier Ltd.)

Intrahepatic cholangiocarcinoma (iCCA) has over the last 10-20 years become the focus of increasing concern, largely due to its rising incidence and high mortality rates worldwide. The significant increase in mortality rates from this primary hepatobiliary cancer, particularly over the past decade, has coincided with a rapidly growing interest among clinicians, investigators, and patient advocates to seek greater mechanistic insights and more effective biomarker-driven targeted approaches for managing and/or preventing this challenging liver cancer. In addition to discussing challenges posed by this aggressive cancer, this review will emphasize recent epidemiological, basic, and translational research findings for iCCA. In particular, we will highlight emerging demographic changes and evolving risk factors, the critical role of the tumor microenvironment, extracellular vesicle biomarkers and therapeutics, intertumoral and intratumoral heterogeneity, and current and emerging targeted therapies regarding iCCA. Specifically, recent evidence linking non-bile duct medical conditions, such as nonalcoholic fatty liver disease and nonspecific cirrhosis, to intrahepatic cholangiocarcinogenesis together with geographic and ethnic variation will be assessed. Recent developments concerning the roles played by transforming growth factor-β and platelet-derived growth factor D in driving the recruitment and expansion of cancer-associated myofibroblasts within cholangiocarcinoma (CCA) stroma as well as their therapeutic implications will also be discussed. In addition, the potential significance of extracellular vesicles as bile and serum biomarkers and therapeutic delivery systems for iCCA will be described. An integrated systems approach to classifying heterogeneous iCCA subtypes will be further highlighted, and recent clinical trials and emerging targeted therapies will be reviewed, along with recommendations for future translational research opportunities. Established international CCA networks are now facilitating collaborations aimed at advancing iCCA translational and clinical research., (© 2018 by the American Association for the Study of Liver Diseases.)

Qidong (Jiangsu, China) has been of interest to cancer epidemiologists and biologists because, until recently, it was an endemic area for liver cancer, having amongst the highest incidence rates in the world. The establishment of the Qidong Cancer Registry together with the Qidong Liver Cancer Institute in 1972 has charted the patterns of liver cancer incidence and mortality in a stable population throughout a period of enormous economic, social, and environmental changes as well as of improvements in health care delivery. Updated incidence trends in Qidong are described. Notably, the China age-standardized incidence rate for liver cancer has dropped by over 50% in the past several decades. Molecular epidemiologic and genomic deep sequencing studies have affirmed that infection with hepatitis B virus as well as dietary exposure to aflatoxins through contamination of dietary staples such as corn, and to microcystins - blue-green algal toxins found in ditch and pond water - were likely important etiologic factors that account for the high incidence of liver cancer in this region. Public health initiatives to facilitate universal vaccination of newborns against HBV and to improve drinking water sources in this rural area, as well as economic and social mandates serendipitously facilitating dietary diversity, have led to precipitous declines in exposures to these etiologic factors, concomitantly driving substantive declines in the liver cancer incidence seen now in Qidong. In this regard, Qidong serves as a template for the global impact that a package of intervention strategies may exert on cancer burden.

Background: There are no data on the prevalence of non-alcoholic fatty liver disease (NAFLD) in general population samples in Guatemala or in other Central American countries. The prevalence and distribution of NAFLD and its associated risk factors were evaluated in a population-based sample of adults in Guatemala., Methods: Cross-sectional study of 411 men and women 40 years of age or older residing in urban and rural areas of Guatemala. Metabolic outcomes included obesity, central obesity, hypercholesterolemia, diabetes, and metabolic syndrome (MetS). Liver disease outcomes included elevated liver enzymes, elevated Fatty Liver Index (FLI), and elevated FIB-4 score., Results: The overall prevalence of obesity, central obesity, diabetes, and MetS were 30.9, 74.3, 21.6, and 64.2%, respectively. The fully-adjusted prevalence ratios (95% CI) for obesity, central obesity, diabetes, and MetS comparing women to men were 2.83 (1.86-4.30), 1.72 (1.46-2.02), 1.18 (1.03-1.34), and 1.87 (1.53-2.29), respectively. The overall prevalence of elevated liver enzymes (ALT or AST), elevated FLI, and elevated FIB-4 scores were 38.4, 60.1, and 4.1%, respectively. The fully-adjusted prevalence ratios (95% CI) for elevated liver enzymes (either ALT or AST) and elevated FLI score comparing women to men were 2.99 (1.84-4.86) and 1.47 (1.18-1.84), respectively., Conclusions: The prevalence of metabolic abnormalities and liver outcomes in this general population study was very high. The prevalence of metabolic and liver abnormalities was particularly high among women, an observation that could explain the atypical 1:1 male to female ratio of liver cancer in Guatemala., (Copyright © 2018 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. All rights reserved.)

Dietary exposure to aflatoxin B 1 (AFB 1 ) is a significant contributor to the incidence of hepatocellular carcinomas globally. AFB 1 exposure leads to the formation of AFB 1 -N 7 -guanine (AFB 1 -N 7 -Gua) and two diastereomers of the imidazole ring-opened 8,9-dihydro-8-(2,6-diamino-4-oxo-3,4-dihydropyrimid-5-yl-formamido)-9-hydroxyaflatoxin B 1 (AFB 1 -FapyGua) in DNA. These adducts lead to G → T transversion mutations with the ring-opened adduct being more mutagenic than the cationic species. Accurate measurement of these three adducts as biomarkers in DNA and urine will help identify dietary exposure to AFB 1 as a risk factor in the development of hepatocellular carcinoma worldwide. Herein, we report an improved methodology for the measurement of AFB 1 -N 7 -Gua and the two diastereomers of AFB 1 -FapyGua using liquid chromatography-tandem mass spectrometry with isotope dilution. We measured the levels of these compounds in liver DNA of six control mice and six AFB 1 -treated mice. Levels varying from 1.5 to 45 lesions/10 6 DNA bases in AFB 1 -treated mice were detected depending on the compound and animal. No background levels of these adducts were detected in control mice. We also tested whether the AFB 1 treatment caused oxidatively induced DNA base damage using gas chromatography-tandem mass spectrometry with isotope dilution. Although background levels of several pyrimidine- and purine-derived lesions were detected, no increases in these levels were found upon AFB 1 treatment of mice. On the other hand, significantly increased levels of (5' R)- and (5' S)-8,5'-cyclo-2'-deoxyadenosines were observed in liver DNA of AFB 1 -treated mice. The impact of this work is expected to achieve the accurate measurement of three AFB 1 -DNA adducts and oxidatively induced DNA lesions as biomarkers of AFB 1 exposure as germane to investigations designed for the prevention of aflatoxin-related hepatocellular carcinomas and for determining the effects of genetic deficiencies in human populations.

Background: Exposure to particulate matter (PM) is increasing worldwide as a result of increased human activity, the rapid industrialization of developing countries, and effects of climate change. Adverse effects of PM on human health are well documented, and because PM exposure occurs mostly through the airways, PM has especially deleterious impact on the lungs., Objective: We investigated whether surrogate PM particles like carbon black (CB), diesel exhaust particle (DEP), coal fly ash (CFA) can recapitulate the allergic airway inflammatory response induced by urban particulate matter., Methods: We compared the pro-inflammatory potential of urban PM collected from New York (NYC) and Baltimore (Balt) with CB, DEP and CFA surrogate PM particles. Eight to ten weeks old BALB/cJ mice were exposed through the airways to particulate material, and markers of airway inflammation were determined. Specifically, we assessed cellular influx, mucus production, lung function, cytokine levels as well as immune cell profiling of the lungs., Results: Herein, we demonstrate that exposure to equivalent mass of stand-alone surrogate PM particles like CB, DEP and CFA, fails to induce significant airway inflammatory response seen after similar exposure to urban PMs. Specifically, we observe that PM collected from New York (NYC) and Baltimore city (Balt) triggers a mixed Th2/Th17 response accompanied by eosinophilic and neutrophilic influx, mucus production and airway hyperresponsiveness (AHR). Although the immune profile of NYC and Baltimore PMs are similar, they demonstrate considerable differences in their potency. Baltimore PM induced more robust airway inflammation, AHR, and Th2 cytokine production, possibly due to the greater metal content in Baltimore PM., Conclusions: Urban particulate matter with its unique physiochemical properties and heterogeneous composition elicits a mixed Th2/Th17 allergic airway response that is not seen after similar exposures to surrogate PM particles., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Qidong hepatitis B virus (HBV) infection cohort (QBC) is a prospective community-based study designed to investigate causative factors of primary liver cancer (PLC) in Qidong, China, where both PLC and HBV infection are highly endemic. Residents aged 20-65 years, living in seven townships of Qidong, were surveyed using hepatitis B surface antigen (HBsAg) serum test and invited to participate in QBC from June 1991 to December 1991. A total of 852 and 786 participants were enrolled in HBsAg-positive and HBsAg-negative sub-cohorts in May 1992, respectively. All participants were actively followed up in person, received HBsAg, alanine aminotransferase (ALT), alpha-fetoprotein (AFP) tests and upper abdominal ultrasonic examination, and donated blood and urine samples once or twice a year. The total response rate was 99.6%, and the number of incident PLC was 201 till the end of February 2017. The ratio of incidence rates was 12.32 (95% confidence interval[CI]=7.16-21.21, P < 0.0001) in HBsAg-positive arm compared with HBsAg-negative arm. The relative risk of PLC was 13.25 (95% CI=6.67-26.33, P < 0.0001) and 28.05 (95% CI=13.87-56.73, P < 0.0001) in the HBsAg+/HBeAg- group and the HBsAg+/HBeAg+ group, respectively, as compared to the HBsAg-/HBeAg- group. A series of novel PLC-related mutations including A2159G, A2189C and G2203W at the C gene, A799G, A987G and T1055A at the P gene of HBV genome were identified by using samples from the cohort. The mutation in hepatitis B virus (HBV) basal core promoter region of HBV genome has an accumulative effect on the occurrence of PLC. In addition, the tripartite relationship of aflatoxin exposure, P53 mutation and PLC was also investigated. Dynamic prediction model for PLC risk by using its long-term follow-up information and serial blood samples for QBC was developed. This model is expected to improve the efficiency of PLC screening in HBV infection individuals., Competing Interests: Conflict of interest None declared

Liver cancer is an emerging global health issue, with rising incidence in both the United States and the economically developing world. Although Guatemala experiences the highest rates of this disease in the Western hemisphere and a unique 1:1 distribution in men and women, few studies have focused on this population. Thus, we determined the prevalence and correlates of aflatoxin B1 (AFB1) exposure and hepatitis virus infection in Guatemalan adults. Healthy men and women aged ≥40 years (n = 461), residing in five departments of Guatemala, were enrolled in a cross-sectional study from May-October of 2016. Serum AFB1-albumin adducts were quantified using isotope dilution mass spectrometry. Multivariate linear regression was used to assess relationships between AFB1-albumin adduct levels and demographic factors. Biomarkers of hepatitis B virus and hepatitis C virus infection were assessed by immunoassay and analyzed by Fisher's exact test. AFB1-albumin adducts were detected in 100% of participants, with a median of 8.4 pg/mg albumin (range, 0.2-814.8). Exposure was significantly higher (p<0.05) in male, rural, low-income, and less-educated participants than in female, urban, and higher socioeconomic status participants. Hepatitis B and C seropositivity was low (0.9% and 0.5%, respectively). Substantial AFB1 exposure exists in Guatemalan adults, concurrent with low prevalence of hepatitis virus seropositivity. Quantitatively, AFB1 exposures are similar to those previously found to increase risk for liver cancer in Asia and Africa. Mitigation of AFB1 exposure may reduce liver cancer incidence and mortality in Guatemala, warranting further investigation.

Aflatoxin B 1 (AFB 1 ) is a potent human and animal hepatocarcinogen. To investigate the effects of aflatoxin on miRNA expression during the initiation phase of carcinogenesis, next-generation sequencing was used to analyze liver tissues from F344 rats exposed to 200 μg/kg per day AFB 1 for 4 week. A panel of miRNAs was identified that was upregulated with AFB 1 treatment compared to controls: rno-miR-434-3p, rno-miR-411-5p, rno-miR-221-3p, rno-miR-127-3p, rno-miR-205, rno-miR-429, rno-miR-34a-5p, rno-miR-181c-3p, rno-miR-200b-3p, and rno-miR-541-5p. Analysis of rat livers exposed to AFB 1 plus the chemopreventive triterpenoid CDDO-Im revealed a striking abrogation of this upregulation. These changes were validated by real-time PCR. We also explored the temporal variation in expression of the candidate miRNAs during the 4-week dosing period. Most of the candidate miRNAs were upregulated at week 1 and increased for the duration of AFB 1 dosing over the 4-week period. Treatment with CDDO-Im ameliorated these effects at all time points. All candidate miRNAs were detectable in serum from aflatoxin treated animals; however, there was no significant difference in expression for 7 of the 11 miRNAs examined. Exposure to AFB 1 upregulated miR-122-5p (fivefold), 34a-5p (13-fold), and 181c-3p (170-fold) compared with controls. The findings from this study give insight into epigenetic changes induced by aflatoxin taking place during the initial step of carcinogenesis., (© 2017 Wiley Periodicals, Inc.)

Pregnancy is a complex physiological state, in which the metabolism of endogenous as well as exogenous agents is ostensibly altered. One exogenous agent of concern is the hepatocarcinogen aflatoxin B1 (AFB1), a foodborne fungal toxin, that requires phase I metabolic oxidation for conversion to its toxic and carcinogenic form, the AFB1-8,9-exo-epoxide. The epoxide interacts with cellular targets causing toxicity and cell death; these targets include the covalent modification of DNA leading to mutations that can initiate malignant transformation. The main detoxification pathway of the AFB1-epoxide involves phase II metabolic enzymes including the glutathione-S-transferase (GST) family. Pregnancy can modulate both phase I and II metabolism and alter the biological potency of AFB1. The present work investigated the impact of pregnancy on AFB1 exposure in mice. A single IP dose of 6 mg/kg AFB1 was administered to pregnant C57BL/6 J mice at gestation day 14 and matched non-pregnant controls. Pregnant mice accumulated 2-fold higher AFB1-N7-guanine DNA adducts in the liver when compared with nonpregnant controls 6 h post-exposure. Enhanced DNA adduct formation in pregnant animals paralleled elevated hepatic protein expression of mouse CYP1A2 and mouse homologs of human CYP3A4, phase I enzymes capable of bioactivating AFB1. Although phase II enzymes GSTA1/2 showed decreased protein expression, GSTA3, the primary enzymatic protection against the AFB1-epoxide, was unaffected at the protein level. Taken together, our results reveal that pregnancy may constitute a critical window of susceptibility for maternal health, and provide insight into the biochemical factors that could explain the underlying risks., (© The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology.)

Selenium deficiency or excess may have public health consequences, yet selenium status is infrequently characterized in populations, perhaps due to challenges in methodology. We are seeking to identify plasma proteins, using proteomics discovery and validation approaches, to serve as proxies for micronutrient status, including selenium, which may in the future be more readily assessed by robust, affordable field methods. In a sample of rural Nepalese children 6 - 8 years old (n = 500), the prevalence of selenium deficiency was 13.6 and 60.9 % at plasma selenium concentrations < 0.60 and < 0.89 µmol/L, respectively, assessed by atomic absorption spectroscopy. Relative abundance of selenoprotein P isoform 1 (SEPP1), glutathione reductase-3, and apolipoprotein A2 from discovery-based experiments was correlated with plasma selenium with a false discovery rate < 10 % (i. e., q < 0.10), all with p < 0.001. In linear mixed effects regression models to predict plasma selenium, only SEPP1 was significant (R 2 = 0.63), estimating 8.2 % (95 % CI: 3.9 - 12.6) and 65.5(61.4 - 69.7)% of the in-sample population as deficient at each respective cut-off. Targeted quantification of SEPP1 in a preliminary series of specimens (n = 19) as a validation of the discovery approach revealed a high correlation with plasma selenium (r = 0.757, p = 0.0002). Plasma proteomics can identify valid plasma protein indicators of micronutrient status, as shown with selenium, comprising a step toward making population assessment of selenium status in vulnerable groups more accessible.

Global distribution of hepatocellular carcinomas (HCCs) is dominated by its incidence in developing countries, accounting for >700,000 estimated deaths per year, with dietary exposures to aflatoxin (AFB 1 ) and subsequent DNA adduct formation being a significant driver. Genetic variants that increase individual susceptibility to AFB 1 -induced HCCs are poorly understood. Herein, it is shown that the DNA base excision repair (BER) enzyme, DNA glycosylase NEIL1, efficiently recognizes and excises the highly mutagenic imidazole ring-opened AFB 1 -deoxyguanosine adduct (AFB 1 -Fapy-dG). Consistent with this in vitro result, newborn mice injected with AFB 1 show significant increases in the levels of AFB 1 -Fapy-dG in Neil1 -/- vs. wild-type liver DNA. Further, Neil1 -/- mice are highly susceptible to AFB 1 -induced HCCs relative to WT controls, with both the frequency and average size of hepatocellular carcinomas being elevated in Neil1 -/- The magnitude of this effect in Neil1 -/- mice is greater than that previously measured in Xeroderma pigmentosum complementation group A (XPA) mice that are deficient in nucleotide excision repair (NER). Given that several human polymorphic variants of NEIL1 are catalytically inactive for their DNA glycosylase activity, these deficiencies may increase susceptibility to AFB 1 -associated HCCs., Competing Interests: The authors declare no conflict of interest.