Cisplatin in the era of PARP inhibitors and immunotherapy

Platinum compounds such as cisplatin, carboplatin and oxaliplatin are widely used in chemotherapy. Cisplatin induces cytotoxic DNA damage that blocks DNA replication and gene transcription, leading to arrest of cell proliferation. Although platinum therapy alone is effective against many tumors, cancer cells can adapt to the treatment and gain resistance. The mechanisms for cisplatin resistance are complex, including low DNA damage formation, high DNA repair capacity, changes in apoptosis signaling pathways, rewired cell metabolisms, and others. Drug resistance compromises the clinical efficacy and calls for new strategies by combining cisplatin with other therapies. Exciting progress in cancer treatment, particularly development of poly (ADP-ribose) polymerase (PARP) inhibitors and immune checkpoint inhibitors, opened a new chapter to combine cisplatin with these new cancer therapies. In this Review, we discuss how platinum synergizes with PARP inhibitors and immunotherapy to bring new hope to cancer patients.

Industrial air pollution and low birth weight in New Mexico, USA

In recent decades, the low birth weight (LBW) rate in New Mexico has consistently exceeded the Unites States average. Maternal exposure to air pollution during pregnancy may be a significant contributor to LBW in offspring. This study investigated the links between maternal residential exposure to air pollution from industrial sources and the risk of LBW in offspring. The analysis included 22,375 LBW cases and 233,340 controls. It focused on 14 common chemicals listed in the Toxic Release Inventory (TRI) and monitoring datasets, which have abundant monitoring samples. The Emission Weighted Proximity Model (EWPM) was used to calculate maternal air pollution exposure intensity. Adjusted odds ratios (adjORs) were calculated using binary logistic regressions to examine the association between maternal residential air pollution exposure and LBW, while controlling for potential confounders, such as the maternal age, race/ethnicity, gestational age, prenatal care, education level, consumption of alcohol during pregnancy, public health regions, child's sex, and the year of birth. Multiple comparison correction was applied using the False Discovery Rate approach. The results showed that maternal residential exposure to 1,2,4-trimethylbenzene, benzene, chlorine, ethylbenzene, and styrene had significant positive associations with LBW in offspring, with adjusted odds ratios ranging from 1.10 to 1.13. These five chemicals remained as significant risk factors after dividing the estimated exposure intensities into four categories. In addition, significant linear trends were found between LBW and maternal exposure to each of the five identified chemicals. Furthermore, 1,2,4-trimethylbenzene was identified as a risk factor to LBW for the first time. The findings of this study should be confirmed through additional epidemiological, biological, and toxicological studies.

Pan-cancer mutational signature surveys correlated mutational signature with geospatial environmental exposures and viral infections

Background

Cancer has been disproportionally affecting minorities. Genomic-based cancer disparity analyses have been less common than conventional epidemiological studies. In the past decade, mutational signatures have been established as characteristic footprints of endogenous or exogenous carcinogens.

Methods

Integrating datasets of diverse cancer types from The Cancer Genome Atlas and geospatial environmental risks of the registry hospitals from the United States Environmental Protection Agency, we explored mutational signatures from the aspect of racial disparity concerning pollutant exposures. The raw geospatial environmental exposure data were refined to 449 air pollutants archived and modeled from 2007 to 2017 and aggregated to the census county level. Additionally, hepatitis B and C viruses and human papillomavirus infection statuses were incorporated into analyses for skin cancer, cervical cancer, and liver cancer.

Results

Mutation frequencies of key oncogenic genes varied substantially between different races. These differences were further translated into differences in mutational signatures. Survival analysis revealed that the increased pollution level is associated with worse survival. The analysis of the oncogenic virus revealed that aflatoxin, an affirmed carcinogen for liver cancer, was higher in Asian liver cancer patients than in White patients. The aflatoxin mutational signature was exacerbated by hepatitis infection for Asian patients but not for White patients, suggesting a predisposed genetic or genomic disadvantage for Asians concerning aflatoxin.

Conclusions

Environmental pollutant exposures increase a mutational signature level and worsen cancer prognosis, presenting a definite adverse risk factor for cancer patients.

Application of artificial intelligence in quantifying lung deposition dose of black carbon in people with exposure to ambient combustion particles

BACKGROUND

Understanding lung deposition dose of black carbon is critical to fully reconcile epidemiological evidence of combustion particles induced health effects and inform the development of air quality metrics concerning black carbon. Macrophage carbon load (MaCL) is a novel cytology method that quantifies lung deposition dose of black carbon, however it has limited feasibility in large-scale epidemiological study due to the labor-intensive manual counting.

OBJECTIVE

To assess the association between MaCL and episodic elevation of combustion particles; to develop artificial intelligence based counting algorithm for MaCL assay.

METHODS

Sputum slides were collected during episodic elevation of ambient PM2.5 (n = 49, daily PM2.5 > 10 µg/m3 for over 2 weeks due to wildfire smoke intrusion in summer and local wood burning in winter) and low PM2.5 period (n = 39, 30-day average PM2.5 < 4 µg/m3) from the Lovelace Smokers cohort.

RESULTS

Over 98% individual carbon particles in macrophages had diameter <1 µm. MaCL levels scored manually were highly responsive to episodic elevation of ambient PM2.5 and also correlated with lung injury biomarker, plasma CC16. The association with CC16 became more robust when the assessment focused on macrophages with higher carbon load. A Machine-Learning algorithm for Engulfed cArbon Particles (MacLEAP) was developed based on the Mask Region-based Convolutional Neural Network. MacLEAP algorithm yielded excellent correlations with manual counting for number and area of the particles. The algorithm produced associations with ambient PM2.5 and plasma CC16 that were nearly identical in magnitude to those obtained through manual counting.

IMPACT STATEMENT

Understanding lung black carbon deposition is crucial for comprehending health effects of combustion particles. We developed "Machine-Learning algorithm for Engulfed cArbon Particles (MacLEAP)", the first artificial intelligence algorithm for quantifying airway macrophage black carbon. Our study bolstered the algorithm with more training images and its first use in air pollution epidemiology. We revealed macrophage carbon load as a sensitive biomarker for heightened ambient combustion particles due to wildfires and residential wood burning.

Maternal exposure to metal components of PM2.5 and low birth weight in New Mexico, USA

Infants with low birth weight (LBW) are more likely to have health problems than normal weight infants. In studies examining the associations between particulate matter (PM) exposures and LBW, there is a tendency to focus on PM2.5 as a whole. However, insufficient information is available regarding the effects of different components of PM2.5 on birth weight. This study identified the associations between maternal exposure to 10 metal components of PM2.5 and LBW in offspring based on small area (divided by population size) level data in New Mexico, USA, from 2012 to 2016. This study used a pruned feed-forward neural network (pruned-FNN) approach to estimate the annual average exposure index to each metal component in each small area. The linear regression model was employed to examine the association between maternal PM2.5 metal exposures and LBW rate in small areas, adjusting for the female percentage and race/ethnicity compositions, marriage status, and educational level in the population. An interquartile range increase in maternal exposure to mercury and chromium of PM2.5 increased LBW rate by 0.43% (95% confidence interval (CI): 0.18-0.68%) and 0.63% (95% CI: 0.15-1.12%), respectively. These findings suggest that maternal exposure to metal components of air pollutants may increase the risk of LBW in offspring. With no similar studies in New Mexico, this study also posed great importance because of a higher LBW rate in New Mexico than the national average. These findings provide critical information to inform further epidemiological, biological, and toxicological studies.

Computational risk modeling of underground coal mines based on NIOSH employment demographics

Objective

To investigate the feasibility of predicting the risk of underground coal mine operations using data from the National Institute for Occupational Safety and Health (NIOSH).

Methods

A total of 22,068 data entries from 3,982 unique underground coal mines from 1990 to 2020 were extracted from the NIOSH mine employment database. We defined the risk index of a mine as the ratio between the number of injuries and the size of the mine. Several machine learning models were used to predict the risk of a mine based on its employment demographics (i.e., number of underground employees, number of surface employees, and coal production). Based on these models, a mine was classified into a "low-risk" or "high-risk" category and assigned with a fuzzy risk index. Risk probabilities were then computed to generate risk profiles and identify mines with potential hazards.

Results

NIOSH mine demographic features yielded a prediction performance with an AUC of 0.724 (95% CI 0.717-0.731) based on the last 31-years' mine data and an AUC of 0.738 (95% CI: 0.726, 0.749) on the last 16-years' mine data. Fuzzy risk score shows that risk is greatest in mines with an average of 621 underground employees and a production of 4,210,150 tons. The ratio of tons/employee maximizes the risk at 16,342.18 tons/employee.

Conclusion

It is possible to predict the risk of underground coal mines based on their employee demographics and optimizing the allocation and distribution of employees in coal mines can help minimize the risk of accidents and injuries.

Disproportionate impact of COVID-19 severity and mortality on hospitalized American Indian/Alaska Native patients

Epidemiological data across the United States of America illustrate health disparities in COVID-19 infection, hospitalization, and mortality by race/ethnicity. However, limited information is available from prospective observational studies in hospitalized patients, particularly for American Indian or Alaska Native (AI/AN) populations. Here, we present risk factors associated with severe COVID-19 and mortality in patients (4/2020-12/2021, n = 475) at the University of New Mexico Hospital. Data were collected on patient demographics, infection duration, laboratory measures, comorbidities, treatment(s), major clinical events, and in-hospital mortality. Severe disease was defined by COVID-related intensive care unit requirements and/or death. The cohort was stratified by self-reported race/ethnicity: AI/AN (30.7%), Hispanic (47.0%), non-Hispanic White (NHW, 18.5%), and Other (4.0%, not included in statistical comparisons). Despite similar timing of infection and comparable comorbidities, admission characteristics for AI/AN patients included younger age (P = 0.02), higher invasive mechanical ventilation requirements (P = 0.0001), and laboratory values indicative of more severe disease. Throughout hospitalization, the AI/AN group also experienced elevated invasive mechanical ventilation (P < 0.0001), shock (P = 0.01), encephalopathy (P = 0.02), and severe COVID-19 (P = 0.0002), consistent with longer hospitalization (P < 0.0001). Self-reported AI/AN race/ethnicity emerged as the highest risk factor for severe COVID-19 (OR = 3.19; 95% CI = 1.70-6.01; P = 0.0003) and was a predictor of in-hospital mortality (OR = 2.35; 95% CI = 1.12-4.92; P = 0.02). Results from this study highlight the disproportionate impact of COVID-19 on hospitalized AI/AN patients, who experienced more severe illness and associated mortality, compared to Hispanic and NHW patients, even when accounting for symptom onset and comorbid conditions. These findings underscore the need for interventions and resources to address health disparities in the COVID-19 pandemic.

Context-aware deep network for coronary artery stenosis classification in coronary CT angiography

Automatic coronary artery stenosis grading plays an important role in the diagnosis of coronary artery disease. Due to the difficulty of learning the informative features from varying grades of stenosis, it is still a challenging task to identify coronary artery stenosis from coronary CT angiography (CCTA). In this paper, we propose a context-aware deep network (CADN) for coronary artery stenosis classification. The proposed method integrates 3D CNN with Transformer to improve the feature representation of coronary artery stenosis in CCTA. We evaluate the proposed method on a multicenter dataset (APOLLO study with NCT05509010). Experimental results show that our proposed method can achieve the accuracy of 0.84, 0.83, and 0.86 for stenosis diagnosis on the lesion, artery, and patient levels, respectively.

Site-specific Atg13 methylation-mediated autophagy regulates epithelial inflammation in PM2.5-induced pulmonary fibrosis

Fine particulate matters (PM2.5) increased the risk of pulmonary fibrosis. However, the regulatory mechanisms of lung epithelium in pulmonary fibrosis remained elusive. Here we developed PM2.5-exposure lung epithelial cells and mice models to investigate the role of autophagy in lung epithelia mediating inflammation and pulmonary fibrosis. PM2.5 exposure induced autophagy in lung epithelial cells and then drove pulmonary fibrosis by activation of NF-κB/NLRP3 signaling pathway. PM2.5-downregulated ALKBH5 protein expression promotes m6A modification of Atg13 mRNA at site 767 in lung epithelial cells. Atg13-mediated ULK complex positively regulated autophagy and inflammation in epithelial cells with PM2.5 treatment. Knockout of ALKBH5 in mice further accelerated ULK complex-regulated autophagy, inflammation and pulmonary fibrosis. Thus, our results highlighted that site-specific m6A methylation on Atg13 mRNA regulated epithelial inflammation-driven pulmonary fibrosis in an autophagy-dependent manner upon PM2.5 exposure, and it provided target intervention strategies towards PM2.5-induced pulmonary fibrosis.

Medical Imaging Compatibility of Magnesium- and Iron-Based Bioresorbable Flow Diverters

BACKGROUND AND PURPOSE

Bioresorbable flow diverters are under development to mitigate complications associated with conventional flow-diverter technology. One proposed advantage is the ability to reduce metal-induced artifacts in follow-up medical imaging. In the current work, the medical imaging compatibility of magnesium- and iron-based bioresorbable flow diverters is assessed relative to an FDA-approved control in phantom models.

MATERIALS AND METHODS

Bioresorbable flow diverters, primarily composed of braided magnesium or antiferromagnetic iron alloy wires, were compared with an FDA-approved control flow diverter. The devices were assessed for MR imaging safety in terms of magnetically induced force and radiofrequency heating using 1.5T, 3T, and 7T field strength clinical scanners. The devices were deployed in phantom models, and metal-induced image artifacts were assessed in the 3 MR imaging scanners and a clinical CT scanner following clinical scan protocols; device visibility was assessed under fluoroscopy.

RESULTS

The magnesium-based bioresorbable flow diverter, iron-based bioresorbable flow diverter, and the control device all demonstrated MR imaging safety in terms of magnetically induced force and radiofrequency heating at all 3 field strengths. The bioresorbable flow diverters did not elicit excessive MR imaging artifacts at any field strength relative to the control. Furthermore, the bioresorbable flow diverters appeared to reduce blooming artifacts in CT relative to the control. The iron-based bioresorbable flow diverter and control device were visible under standard fluoroscopy.

CONCLUSIONS

We have demonstrated the baseline medical imaging compatibility of magnesium and antiferromagnetic iron alloy bioresorbable flow diverters. Future work will evaluate the medical imaging characteristics of the bioresorbable flow diverters in large-animal models.

Alterations to biomarkers related to long-term exposure to diesel exhaust at concentrations below occupational exposure limits in the European Union and the USA

BACKGROUND

We previously found that occupational exposure to diesel engine exhaust (DEE) was associated with alterations to 19 biomarkers that potentially reflect the mechanisms of carcinogenesis. Whether DEE is associated with biological alterations at concentrations under existing or recommended occupational exposure limits (OELs) is unclear.

METHODS

In a cross-sectional study of 54 factory workers exposed long-term to DEE and 55 unexposed controls, we reanalysed the 19 previously identified biomarkers. Multivariable linear regression was used to compare biomarker levels between DEE-exposed versus unexposed subjects and to assess elemental carbon (EC) exposure-response relationships, adjusted for age and smoking status. We analysed each biomarker at EC concentrations below the US Mine Safety and Health Administration (MSHA) OEL (<106 µg/m3), below the European Union (EU) OEL (<50 µg/m3) and below the American Conference of Governmental Industrial Hygienists (ACGIH) recommendation (<20 µg/m3).

RESULTS

Below the MSHA OEL, 17 biomarkers were altered between DEE-exposed workers and unexposed controls. Below the EU OEL, DEE-exposed workers had elevated lymphocytes (p=9E-03, false discovery rate (FDR)=0.04), CD4+ count (p=0.02, FDR=0.05), CD8+ count (p=5E-03, FDR=0.03) and miR-92a-3p (p=0.02, FDR=0.05), and nasal turbinate gene expression (first principal component: p=1E-06, FDR=2E-05), as well as decreased C-reactive protein (p=0.02, FDR=0.05), macrophage inflammatory protein-1β (p=0.04, FDR=0.09), miR-423-3p (p=0.04, FDR=0.09) and miR-122-5p (p=2E-03, FDR=0.02). Even at EC concentrations under the ACGIH recommendation, we found some evidence of exposure-response relationships for miR-423-3p (ptrend=0.01, FDR=0.19) and gene expression (ptrend=0.02, FDR=0.19).

CONCLUSIONS

DEE exposure under existing or recommended OELs may be associated with biomarkers reflective of cancer-related processes, including inflammatory/immune response.

Abstract 3505: Cancer disparities in race exposed through geospatial analysis of mutational signatures and environmental exposure

Background: Cancer has been disproportionally affecting minorities in the US due to socioeconomic, environmental, and genetic disparities. Cancer disparities are usually measured in incidence, mortality, survival, etc. Genomic-based cancer disparity analyses have been less common. In the past decade, mutational signatures were proposed as characteristic footprints of endogenous or exogenous carcinogens, which remarkably propelled the progress of genomic cancer research. The disparities caused by uneven exposure to environmental pollutants may be recorded in mutational signatures.

Method: The Cancer Genome Altas is one of the richest genomic cancer datasets, empowering hundreds of secondary and tertiary cancer studies. One aspect of TCGA data that is seldomly utilized is geospatial information. Based on the contribution hospital location, we estimated the patients’ approximate location. Furthermore, utilizing data on 450 pollutants released by the Environmental Protection Agency from 2007-2017, we were able to establish associations between mutational signatures and certain pollutants. To remove the noise introduced by approximating the location and average pollution level, stringent statistical procedures were applied.

Results: First, we showed that mutation frequencies varied substantially between different races. For example, TP53 was mutated in 46% of Black breast cancer patients, compared to 31% in Whites. Such differences in single genes translated to the level of mutational signatures. Liver cancer has aflatoxin as an affirmed carcinogen, and we compared the quantities of aflatoxin signature across races. It was found that aflatoxin contributed significantly higher (FDR = 0.002) to mutations in Asian than in Caucasians. In-depth analyses revealed that aflatoxin had a strong effect on hepatitis C virus infection in addition to the previously reported effect on hepatitis B virus infection. Similarly, as a known critical player in head and neck tumors, APOBEC signature was found at a significantly higher level (FDR = 0.01) in patients with positive infection of human papillomavirus. Furthermore, analyses from the geospatial perspective revealed several potential associations between pollutants and mutational signatures. For example, the pollutant carbofuran is positively associated with mutational signature SBS10a with the etiology of Polymerase epsilon exonuclease domain mutations (FDR = 0.02).

Summary: We conducted a thorough mutational signature-based cancer disparity analysis. Our results reinforced previously known facts and expectations of oncogene mutations. The novel results demonstrated representative links between various forms of cancer disparity and genomic mutation footprints. Most importantly, such disparities can be interrogated at the mutational signature level and correlated to environmental pollutants.

Citation Format: Yan Guo, Judy Bai, Katherine Ma, Shangyang Xia, Shuguang Leng, Hui Yu, Xi Gong. Cancer disparities in race exposed through geospatial analysis of mutational signatures and environmental exposure [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3505.

Maternal exposure to metal components of PM2.5 and low birth weight in New Mexico, USA

Infants with low birth weight (LBW) are more likely to have health problems than normal weight infants. In studies examining the associations between particulate matter (PM) exposures and LBW, there is a tendency to focus on PM 2.5 as a whole. However, insufficient information is available regarding the effects of different components of PM 2.5 on birth weight. This study identified the associations between maternal exposure to 10 metal components of PM 2.5 and LBW in offspring based on small area (divided by population size) level data in New Mexico, USA, from 2012 to 2016. This study used a pruned feed-forward neural network (pruned-FNN) approach to estimate the annual average exposure index to each metal component in each small area. The linear regression model was employed to examine the association between maternal PM 2.5 metal exposures and LBW rate in small areas, adjusting for the female percentage and race/ethnicity compositions, marriage status and educational level in the population. An interquartile range increase in maternal exposure to mercury and chromium of PM 2.5 increased LBW rate by 0.43% (95% confidence interval (CI): 0.18%-0.68%) and 0.63% (95% CI: 0.15%-1.12%), respectively. These findings suggest that maternal exposure to metal components of air pollutants may increase the risk of LBW in offspring. With no similar studies in New Mexico, this study also posed great importance because of a higher LBW rate in New Mexico than the national average. These findings provide critical information to inform further epidemiological, biological, and toxicological studies.

NLRP3 Disturbs Treg/Th17 Cell Balance to Aggravate Apical Periodontitis

Apical periodontitis is an inflammatory condition that is considered an immunological reaction of the periapical tissue to invading bacteria and their pathogenic components. Recent research has revealed that NLR family pyrin domain containing 3 (NLRP3) is crucial to the pathogenesis of apical periodontitis and serves as a link between innate and adaptive immunity. The balance between regulatory T-cell (Treg) and T helper cell 17 (Th17 cell) determines the direction of the inflammatory response. Therefore, this study aimed to investigate whether NLRP3 exacerbated periapical inflammation by disturbing Treg/Th17 balance and the underlying regulatory mechanisms. In the present study, NLRP3 was raised in apical periodontitis tissues as opposed to healthy pulp tissues. Low NLRP3 expression in dendritic cells (DCs) increased transforming growth factor β secretion while decreasing interleukin (IL)-1β and IL-6 production. The Treg ratio and IL-10 secretion rose when CD4⁺ T cells were cocultured with DCs primed with IL-1β neutralizing antibody (anti-IL-1β) and specific small interfering RNA (siRNA) targeting NLRP3 (siRNA NLRP3), but the proportion of Th17 cells and IL-17 release dropped. Furthermore, siRNA NLRP3-mediated suppression of NLRP3 expression aided Treg differentiation and elevated Foxp3 expression as well as IL-10 production in CD4⁺ T cells. Inhibition of NLRP3 activity by MCC950 boosted the percentage of Tregs while decreasing the ratio of Th17 cells, leading to reduced periapical inflammation and bone resorption. Nigericin administration, however, exacerbated periapical inflammation and bone destruction with an unbalanced Treg/Th17 response. These findings demonstrate that NLRP3 is a pivotal regulator by regulating the release of inflammatory cytokines from DCs or directly suppressing Foxp3 expression to disturb Treg/Th17 balance, thus exacerbating apical periodontitis.

Machine learning accurately quantifies epicardial adipose tissue from non-contrast CT images in coronary artery disease

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): Industry Alignment Fund – Pre-positioning Programme

Background

Epicardial adipose tissue (EAT) is the visceral fat deposit within the pericardium that surrounds the heart and the coronary arteries. EAT volume measured from non-contrast CT (NCCT) has been demonstrated to be significantly associated with adverse cardiovascular risk,1 particularly in patients with coronary artery disease.2 However, routine measurement of EAT volume is still challenging in clinical practice, as it is a tedious manual process and prone to human error.

Purpose

We aimed to develop a fully automated AI toolkit (i.e., AI EAT) for the quantification of EAT from routine NCCT scans and assess its performance in reference to clinical ground truth.

Methods

This is a multicenter study which performs CT scans in 5000 Asian Admixture patients (APOLLO study NCT05509010). In the current stage of this study, NCCT data analysis were conducted in 551 patients with 26,037 images. AI EAT was developed via a novel deep learning framework using an ensemble region-based UNet. The region-based UNet uses 2 component UNet models to perform segmentation of pericardium at the apex region and non-apex region (middle and basal). EAT volume was obtained by automated thresholding of the voxels (-190 to -30 Hounsfield Unit) within the pericardium (Figure 1). The network was trained in 501 patients with 23,712 NCCT images and tested in 50 patients with 2,325 NCCT images. The performance of AI EAT was evaluated with respect to clinical ground truth using Dice similarity coefficient (DSC), Pearson correlation, and Bland-Altman analysis.

Results

The AI EAT quantification process took less than 10 seconds per subject, compared with 20-30 minutes for expert readers. Compared to clinical ground truth, our AI EAT achieved a DSC of 0.96±0.01 and 0.91±0.02 for pericardium and EAT segmentations, respectively. There was strong agreement between the AI EAT and clinical ground truth in deriving the EAT volume (r=0.99, P&lt;0.001) with minimal error of 7±5%.

Conclusion

End-to-end deep learning system accurately quantifies epicardial adipose tissue in standard NCCT images without manual segmentation.

Early natural menopause is associated with poor lung health and increased mortality among female smokers

BACKGROUND

Early natural menopause has been regarded as a biomarker of reproductive and somatic aging. Cigarette smoking is the most harmful factor for lung health and also an established risk factor for early menopause. Understanding the effect of early menopause on health outcomes in middle-aged and older female smokers is important to develop preventive strategies.

OBJECTIVE

This study aimed to examine the associations of early menopause with multiple lung health and aging biomarkers, lung cancer risk, and all-cause and cause-specific mortality in postmenopausal women who were moderate or heavy smokers.

STUDY DESIGN

This study was conducted on postmenopausal women with natural (n=1038) or surgical (n=628) menopause from the Pittsburgh Lung Screening Study. The Pittsburgh Lung Screening Study is a community-based research cohort of current and former smokers, screened with low-dose computed tomography and followed up for lung cancer. Early menopause was defined as occurring before 45 years of age. The analyses were stratified by menopause types because of the different biological and medical causes of natural and surgical menopause. Statistical methods included linear model, generalized linear model, linear mixed-effects model, and time-to-event analysis.

RESULTS

The average age of the 1666 female smokers was 59.4±6.7 years, with 1519 (91.2%) of the population as non-Hispanic Whites and 1064 (63.9%) of the population as current smokers at baseline. Overall, 646 (39%) women reported early menopause, including 198 (19.1%) women with natural menopause and 448 (71.3%) women with surgical menopause (P<.001). Demographic variables did not differ between early and nonearly menopause groups, regardless of menopause type. Significant associations were identified between early natural menopause and higher risk of wheezing (odds ratio, 1.65; P<.01), chronic bronchitis (odds ratio, 1.73; P<.01), and radiographic emphysema (odds ratio, 1.70; P<.001) and lower baseline lung spirometry in an obstructive pattern (-104.8 mL/s for forced expiratory volume in the first second with P<.01, -78.6 mL for forced vital capacity with P=.04, and -2.1% for forced expiratory volume in the first second-to-forced vital capacity ratio with P=.01). In addition, early natural menopause was associated with a more rapid decline of forced expiratory volume in the first second-to-forced vital capacity ratio (-0.16% per year; P=.01) and incident airway obstruction (odds ratio, 2.02; P=.04). Furthermore, women early natural menopause had a 40% increased risk of death (P=.023), which was mainly driven by respiratory diseases (hazard ratio, 2.32; P<.001). Mediation analyses further identified that more than 33.3% of the magnitude of the associations between early natural menopause and all-cause and respiratory mortality were explained by baseline forced expiratory volume in the first second. Additional analyses in women with natural menopause identified that the associations between continuous smoking and subsequent lung cancer risk and cancer mortality were moderated by early menopause status, and females with early natural menopause who continued smoking had the worst outcomes (hazard ratio, >4.6; P<.001). This study did not find associations reported above in female smokers with surgical menopause.

CONCLUSION

Early natural menopause was found to be a risk factor for malignant and nonmalignant lung diseases and mortality in middle-aged and older female smokers. These findings have strong public health relevance as preventive strategies, including smoking cessation and chest computed tomography screening, should target this population (ie, female smokers with early natural menopause) to improve their postmenopausal health and well-being.

Lung Effects of Household Air Pollution

Biomass fuel smoke, secondhand smoke, and oxides of nitrogen are common causes of household air pollution (HAP). Almost 2.4 billion people worldwide use solid fuels for cooking and heating, mostly in low- and middle-income countries. Wood combustion for household heating is also common in many areas of high-income countries, and minorities are particularly vulnerable. HAP in low- and middle-income countries is associated with asthma, acute respiratory tract infections in adults and children, chronic obstructive pulmonary disease, lung cancer, tuberculosis, and respiratory mortality. Although wood smoke exposure levels in high-income countries are typically lower than in lower-income countries, it is similarly associated with accelerated lung function decline, higher prevalence of airflow obstruction and chronic bronchitis, and higher all-cause and respiratory cause-specific mortality. Household air cleaners with high-efficiency particle filters have mixed effects on asthma and chronic obstructive pulmonary disease outcomes. Biomass fuel interventions in low-income countries include adding chimneys to cookstoves, improving biomass fuel combustion stoves, and switching fuel to liquid petroleum gas. Still, the impact on health outcomes is inconsistent. In high-income countries, strategies for reducing biomass fuel-related HAP are centered on community-level woodstove changeout programs, although the results are again inconsistent. In addition, initiatives to encourage home smoking bans have mixed success in households with children. Environmental solutions to reduce HAP have varying success in reducing pollutants and health problems. Improved understanding of indoor air quality factors and actions that prevent degradation or improve polluted indoor air may lead to enhanced environmental health policies, but health outcomes must be rigorously examined.

Association between diesel exhaust exposure and mitochondrial DNA methylation

BACKGROUND

Diesel exhaust is an established human carcinogen, however the mechanisms by which it leads to cancer development are not fully understood. Mitochondrial dysfunction is an established contributor to carcinogenesis. Recent studies have improved our understanding of the role played by epigenetic modifications in the mitochondrial genome on tumorigenesis. In this study, we aim to evaluate the association between diesel engine exhaust (DEE) exposure with mitochondrial DNA (mtDNA) methylation levels in workers exposed to DEE.

METHODS

The study population consisted of 53 male workers employed at a diesel engine manufacturing facility in Northern China who were routinely exposed to diesel exhaust in their occupational setting, as well as 55 unexposed male control workers from other unrelated factories in the same geographic area. Exposure to DEE, elemental carbon, organic carbon, and particulate matter (PM2.5) were assessed. mtDNA methylation for CpG sites (CpGs) from seven mitochondrial genes (D-Loop, MT-RNR1, MT-CO2, MT-CO3, MT-ATP6, MT-ATP8, MT-ND5) was measured in blood samples. Linear regression models were used to estimate the associations between DEE, elemental carbon, organic carbon and PM2.5 exposures with mtDNA methylation levels, adjusting for potential confounders.

RESULTS

DEE exposure was associated with decreased MT-ATP6 (difference= -35.6%, p-value= 0.019) and MT-ATP8 methylation (difference= -30%, p-value= 0.029) compared to unexposed controls. Exposures to elemental carbon, organic carbon, and PM2.5 were also significantly and inversely associated with methylation in MT-ATP6 and MT-ATP8 genes (all p-values < 0.05).

CONCLUSIONS

Our findings suggest that DEE exposure perturbs mtDNA methylation, which may be of importance for tumorigenesis.

Exposure to diesel engine exhaust and alterations to the Cys34/Lys525 adductome of human serum albumin

We investigated whether exposure to carcinogenic diesel engine exhaust (DEE) was associated with altered adduct levels in human serum albumin (HSA) residues. Nano-liquid chromatography-high resolution mass spectrometry (nLC-HRMS) was used to measure adducts of Cys34 and Lys525 residues in plasma samples from 54 diesel engine factory workers and 55 unexposed controls. An untargeted adductomics and bioinformatics pipeline was used to find signatures of Cys34/Lys525 adductome modifications. To identify adducts that were altered between DEE-exposed and unexposed participants, we used an ensemble feature selection approach that ranks and combines findings from linear regression and penalized logistic regression, then aggregates the important findings with those determined by random forest. We detected 40 Cys34 and 9 Lys525 adducts. Among these findings, we found evidence that 6 Cys34 adducts were altered between DEE-exposed and unexposed participants (i.e., 841.75, 851.76, 856.10, 860.77, 870.43, and 913.45). These adducts were biologically related to antioxidant activity.

Utility of Dual-Energy CT to Improve Diagnosis of CSF Leaks on CT Myelography following Lateral Decubitus Digital Subtraction Myelography with Negative Findings

CSF leaks, including CSF-venous fistulas, which cause spontaneous intracranial hypotension, remain difficult to diagnose, even on digital subtraction myelography and CT myelography. Dual-energy CT technology has been used to improve diagnostic utility within multiple organ systems. The capability of dual-energy CT to create virtual monoenergetic images can be leveraged to increase conspicuity of contrast in CSF-venous fistulas and direct epidural CSF leakage to improve the diagnostic utility of CT myelography. Six cases (in 5 patients) are shown in which virtual monoenergetic images demonstrate a leak location that was either occult or poorly visible on high- or low-kilovolt series. This clinical report describes the novel application of dual-energy CT for the detection of subtle CSF leaks including CSF-venous fistulas.

Wood smoke exposure affects lung aging, quality of life, and all-cause mortality in New Mexican smokers

Background

The role of wood smoke (WS) exposure in the etiology of chronic obstructive pulmonary disease (COPD), lung cancer (LC), and mortality remains elusive in adults from countries with low ambient levels of combustion-emitted particulate matter. This study aims to delineate the impact of WS exposure on lung health and mortality in adults age 40 and older who ever smoked.

Methods

We assessed health impact of self-reported “ever WS exposure for over a year” in the Lovelace Smokers Cohort using both objective measures (i.e., lung function decline, LC incidence, and deaths) and two health related quality-of-life questionnaires (i.e., lung disease-specific St. George's Respiratory Questionnaire [SGRQ] and the generic 36-item short-form health survey).

Results

Compared to subjects without WS exposure, subjects with WS exposure had a more rapid decline of FEV1 (− 4.3 ml/s, P = 0.025) and FEV1/FVC ratio (− 0.093%, P = 0.015), but not of FVC (− 2.4 ml, P = 0.30). Age modified the impacts of WS exposure on lung function decline. WS exposure impaired all health domains with the increase in SGRQ scores exceeding the minimal clinically important difference. WS exposure increased hazard for incidence of LC and death of all-cause, cardiopulmonary diseases, and cancers by > 50% and shortened the lifespan by 3.5 year. We found no evidence for differential misclassification or confounding from socioeconomic status for the health effects of WS exposure.

Conclusions

We identified epidemiological evidence supporting WS exposure as an independent etiological factor for the development of COPD through accelerating lung function decline in an obstructive pattern. Time-to-event analyses of LC incidence and cancer-specific mortality provide human evidence supporting the carcinogenicity of WS exposure.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02162-y.

Elevated SARS-CoV-2 in peripheral blood and increased COVID-19 severity in American Indians/Alaska Natives

Epidemiological data across the United States show health disparities in COVID-19 infection, hospitalization, and mortality by race/ethnicity. While the association between elevated SARS-CoV-2 viral loads (VLs) (i.e. upper respiratory tract (URT) and peripheral blood (PB)) and increased COVID-19 severity has been reported, data remain largely unavailable for some disproportionately impacted racial/ethnic groups, particularly for American Indian or Alaska Native (AI/AN) populations. As such, we determined the relationship between SARS-CoV-2 VL dynamics and disease severity in a diverse cohort of hospitalized patients. Results presented here are for study participants (n = 94, ages 21-88 years) enrolled in a prospective observational study between May and October 2020 who had SARS-CoV-2 viral clades 20A, C, and G. Based on self-reported race/ethnicity and sample size distribution, the cohort was stratified into two groups: (AI/AN, n = 43) and all other races/ethnicities combined (non-AI/AN, n = 51). SARS-CoV-2 VLs were quantified in the URT and PB on days 0-3, 6, 9, and 14. The strongest predictor of severe COVID-19 in the study population was the mean VL in PB (OR = 3.34; P = 2.00 × 10-4). The AI/AN group had the following: (1) comparable co-morbidities and admission laboratory values, yet more severe COVID-19 (OR = 4.81; P = 0.014); (2) a 2.1 longer duration of hospital stay (P = 0.023); and (3) higher initial and cumulative PB VLs during severe disease (P = 0.025). Moreover, self-reported race/ethnicity as AI/AN was the strongest predictor of elevated PB VLs (β = 1.08; P = 6.00 × 10-4) and detection of SARS-CoV-2 in PB (hazard ratio = 3.58; P = 0.004). The findings presented here suggest a strong relationship between PB VL (magnitude and frequency) and severe COVID-19, particularly for the AI/AN group.

Genetic Associations and Architecture of Asthma-COPD Overlap

BACKGROUND

Some people have characteristics of both asthma and COPD (asthma-COPD overlap), and evidence suggests they experience worse outcomes than those with either condition alone.

RESEARCH QUESTION

What is the genetic architecture of asthma-COPD overlap, and do the determinants of risk for asthma-COPD overlap differ from those for COPD or asthma?

STUDY DESIGN AND METHODS

We conducted a genome-wide association study in 8,068 asthma-COPD overlap case subjects and 40,360 control subjects without asthma or COPD of European ancestry in UK Biobank (stage 1). We followed up promising signals (P < 5 × 10^-6) that remained associated in analyses comparing (1) asthma-COPD overlap vs asthma-only control subjects, and (2) asthma-COPD overlap vs COPD-only control subjects. These variants were analyzed in 12 independent cohorts (stage 2).

RESULTS

We selected 31 independent variants for further investigation in stage 2, and discovered eight novel signals (P < 5 × 10^-8) for asthma-COPD overlap (meta-analysis of stage 1 and 2 studies). These signals suggest a spectrum of shared genetic influences, some predominantly influencing asthma (FAM105A, GLB1, PHB, TSLP), others predominantly influencing fixed airflow obstruction (IL17RD, C5orf56, HLA-DQB1). One intergenic signal on chromosome 5 had not been previously associated with asthma, COPD, or lung function. Subgroup analyses suggested that associations at these eight signals were not driven by smoking or age at asthma diagnosis, and in phenome-wide scans, eosinophil counts, atopy, and asthma traits were prominent.

INTERPRETATION

We identified eight signals for asthma-COPD overlap, which may represent loci that predispose to type 2 inflammation, and serious long-term consequences of asthma.

A New Frontier in Temporal Bone Imaging: Photon-Counting Detector CT Demonstrates Superior Visualization of Critical Anatomic Structures at Reduced Radiation Dose

BACKGROUND AND PURPOSE

Photon-counting detector CT is a new technology with a limiting spatial resolution of ≤150 μm. In vivo comparisons between photon-counting detector CT and conventional energy-integrating detector CT are needed to determine the clinical impact of photon counting-detector CT in temporal bone imaging.

MATERIALS AND METHODS

Prospectively recruited patients underwent temporal bone CT examinations on an investigational photon-counting detector CT system after clinically indicated temporal bone energy-integrating detector CT. Photon-counting detector CT images were obtained at an average 31% lower dose compared with those obtained on the energy-integrating detector CT scanner. Reconstructed images were evaluated in axial, coronal, and Pöschl planes using the smallest available section thickness on each system (0.4 mm on energy-integrating detector CT; 0.2 mm on photon-counting detector CT). Two blinded neuroradiologists compared images side-by-side and scored them using a 5-point Likert scale. A post hoc reassignment of readers' scores was performed so that the scores reflected photon-counting detector CT performance relative to energy-integrating detector CT.

RESULTS

Thirteen patients were enrolled, resulting in 26 image sets (left and right sides). The average patient age was 63.6 [SD, 13.4] years; 7 were women. Images from the photon-counting detector CT scanner were significantly preferred by the readers in all reconstructed planes (P < .001). Photon-counting detector CT was rated superior for the evaluation of all individual anatomic structures, with the oval window (4.79) and incudostapedial joint (4.75) receiving the highest scores on a Likert scale of 1-5.

CONCLUSIONS

Temporal bone CT images obtained on a photon-counting detector CT scanner were rated as having superior spatial resolution and better critical structure visualization than those obtained on a conventional energy-integrating detector scanner, even with a substantial dose reduction.

Circulatory metabolites trigger ex vivo arterial endothelial cell dysfunction in population chronically exposed to diesel exhaust

Background

Chronic exposure to diesel exhaust has a causal link to cardiovascular diseases in various environmental and occupational settings. Arterial endothelial cell function plays an important role in ensuring proper maintenance of cardiovascular homeostasis and the endothelial cell dysfunction by circulatory inflammation is a hallmark in cardiovascular diseases. Acute exposure to diesel exhaust in controlled exposure studies leads to artery endothelial cells dysfunction in previous study, however the effect of chronic exposure remains unknown.

Results

We applied an ex vivo endothelial biosensor assay for serum samples from 133 diesel engine testers (DETs) and 126 non-DETs with the aim of identifying evidence of increased risk for cardiovascular diseases. Environmental monitoring suggested that DETs were exposed to high levels of diesel exhaust aerosol (282.3 μg/m³ PM_2.5 and 135.2 μg/m³ elemental carbon). Surprisingly, chronic diesel exhaust exposure was associated with a pro-inflammatory phenotype in the ex vivo endothelial cell model, in a dose-dependent manner with CCL5 and VCAM as most affected genes. This dysfunction was not mediated by reduction in circulatory pro-inflammatory factors but significantly associated with a reduction in circulatory metabolites cGMP and an increase in primary DNA damage in leucocyte in a dose-dependent manner, which also explained a large magnitude of association between diesel exhaust exposure and ex vivo endothelial biosensor response. Exogenous cGMP addition experiment further confirmed the induction of ex vivo biosensor gene expressions in endothelial cells treated with physiologically relevant levels of metabolites cGMP.

Conclusion

Serum-borne bioactivity caused the arterial endothelial cell dysfunction may attribute to the circulatory metabolites based on the ex vivo biosensor assay. The reduced cGMP and increased polycyclic aromatic hydrocarbons metabolites-induced cyto/geno-toxic play important role in the endothelial cell dysfunction of workers chronic exposure to diesel exhaust.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12989-022-00463-0.

VCAM-1 Is Upregulated in Uranium Miners Compared to Other Miners

The United States has a rich history of mining including uranium (U)-mining, coal mining, and other metal mining. Cardiovascular diseases (CVD) are largely understudied in miners and recent literature suggests that when compared to non-U miners, U-miners are more likely to report CVD. However, the molecular basis for this phenomenon is currently unknown. In this pilot study, a New Mexico (NM)-based occupational cohort of current and former miners (n = 44) were recruited via a mobile screening clinic for miners. Serum- and endothelial-based endpoints were used to assess circulating inflammatory potential relevant to CVD. Non-U miners reported significantly fewer pack years of smoking than U-miners. Circulating biomarkers of interest revealed that U-miners had significantly greater serum amyloid A (SAA), soluble intercellular adhesion molecule 1 (ICAM-1, ng/mL), soluble vascular cell adhesion molecule 1 (VCAM-1, ng/mL), and VCAM-1 mRNA expression, as determined by the serum cumulative inflammatory potential (SCIP) assay, an endothelial-based assay. Even after adjusting for various covariates, including age, multivariable analysis determined that U-miners had significantly upregulated VCAM-1 mRNA. In conclusion, VCAM-1 may be an important biomarker and possible contributor of CVD in U-miners. Further research to explore this mechanism may be warranted.

A Simple Clinical Prediction Tool for COVID-19 in Primary Care with Epidemiology: Temperature-Leukocytes-CT Results

Background

Effective identification of patients with suspected COVID-19 is vital for the management. This study aimed to establish a simple clinical prediction model for COVID-19 in primary care.

Material/Methods

We consecutively enrolled 60 confirmed cases and 152 suspected cases with COVID-19 into the study. The training cohort consisted of 30 confirmed and 78 suspected cases, whereas the validation cohort consisted of 30 confirmed and 74 suspected cases. Four clinical variables – epidemiological history (E), body temperature (T), leukocytes count (L), and chest computed tomography (C) – were collected to construct a preliminary prediction model (model A). By integerizing coefficients of model A, a clinical prediction model (model B) was constructed. Finally, the scores of each variable in model B were summed up to build the ETLC score.

Results

The preliminary prediction model A was Logit (Y_A)=2.657X₁+1.153X₂+2.125X₃+2.828X₄–10.771, while the model B was Logit (Y_B)=2.5X₁+1X₂+2X₃+3X₄–10. No significant difference was found between the area under the curve (AUC) of model A (0.920, 95% CI: 0.875–0.953) and model B (0.919, 95% CI: 0.874–0.952) (Z=0.035, P=0.972). When ETLC score was more than or equal to 9.5, the sensitivity and specificity for COVID-19 was 76.7% (46/60) and 90.1% (137/152), respectively, and the positive and negative predictive values were 75.4% (46/61) and 90.7% (137/151), respectively.

Conclusions

The ETLC score is helpful for efficiently identifying patients with suspected COVID-19.

Blood leukocyte count as a systemic inflammatory biomarker associated with a more rapid spirometric decline in a large cohort of iron and steel industry workers

Objective

Iron and steel industry workers are exposed to high levels of inhalable dust particles that contain various elements, including metals, and cause occupational lung diseases. We aim to assess the relationship between occupational dust exposure, systemic inflammation, and spirometric decline in a cohort of Chinese iron and steel workers.

Methods

We studied 7513 workers who participated in a Health Surveillance program at Wugang Institute for Occupational Health between 2008 and 2017. Time-weighted exposure intensity (TWEI) of dust was quantified based on self-reported dust exposure history, the experience of occupational hygienists, and historical data of dust exposure for workers with certain job titles. A linear mixed-effects model was used for association analyses.

Results

The average annual change of lung function was − 50.78 ml/year in forced expiratory volume in 1 s (FEV1) and − 34.36 ml/year in forced vital capacity (FVC) in males, and − 39.06 ml/year in FEV1 and − 26.66 ml/year in FVC in females. Higher TWEI prior to baseline was associated with lower longitudinal measurements of FEV1 and FVC but not with their decline rates. Higher WBC and its differential at baseline were associated with lower longitudinal measurements and a more rapid decline of FEV1 and FVC in a dose-dependent monotonically increasing manner. Moreover, the increase of WBC and its differential post-baseline was also associated with a more rapid decline of FEV1 and FVC.

Conclusions

Our findings support the important role of systemic inflammation in affecting the temporal change of lung function in iron and steel industry workers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01849-y.

Small Airway Wall Thickening Assessed by Computerized Tomography Is Associated With Low Lung Function in Chinese Carbon Black Packers

Nanoscale carbon black as virtually pure elemental carbon can deposit deep in the lungs and cause pulmonary injury. Airway remodeling assessed using computed tomography (CT) correlates well with spirometry in patients with obstructive lung diseases. Structural airway changes caused by carbon black exposure remain unknown. Wall and lumen areas of sixth and ninth generations of airways in 4 lobes were quantified using end-inhalation CT scans in 58 current carbon black packers (CBPs) and 95 non-CBPs. Carbon content in airway macrophage (CCAM) in sputum was quantified to assess the dose-response. Environmental monitoring and CCAM showed a much higher level of elemental carbon exposure in CBPs, which was associated with higher wall area and lower lumen area with no change in total airway area for either airway generation. This suggested small airway wall thickening is a major feature of airway remodeling in CBPs. When compared with wall or lumen areas, wall area percent (WA%) was not affected by subject characteristics or lobar location and had greater measurement reproducibility. The effect of carbon black exposure status on WA% did not differ by lobes. CCAM was associated with WA% in a dose-dependent manner. CBPs had lower FEV1 (forced expiratory volume in 1 s) than non-CBPs and mediation analysis identified that a large portion (41-72%) of the FEV1 reduction associated with carbon black exposure could be explained by WA%. Small airway wall thickening as a major imaging change detected by CT may underlie the pathology of lung function impairment caused by carbon black exposure.

[CRL4B complex promotes the development of pancreatic cancer by inhibiting secreted frizzled related protein 1]

Objective: To investigate the role of CUL4B-RING E3 ubiquitin ligase (CRL4B) complex in pancreatic tumorigenesis and the molecular mechanism. Methods: Pancreatic cells were divided into control group (transfected with negative control lentivirus), shCUL4B group (transfected with CUL4B lentivirus), shDDB1 group [transfected with DNA damage binding protein 1 (DDB1) lentivirus], and shCUL4B+ siSFRP1 group (transfected with CUL4B lentivirus and SFRP1-siRNA). RNA-seq was performed in pancreatic cancer cell lines with CUL4B and DDB1 knocked down respectively, to identify the target genes regulated by CRL4B complex. Real-time fluorescent quantitative polymerase chain reaction (qRT-PCR) was used to detect the mRNA expression levels of target genes. Chromatin immunoprecipitation (ChIP) assay was used to identify the target genes directly regulated by CUL4B and DDB1. Western blot was used to detect the protein expression levels of the epithelial-mesenchymal transition (EMT) markers. The EdU cell proliferation test was used to detect cell proliferation ability. The scratch repair test and Transwell cell invasion test were used to detect cell migration and invasion ability. Finally, the sequencing data of pancreatic cancer-related tumor samples and normal samples in GEO, TCGA and GTEx databases were used to analyze the expression correlations of CUL4B, DDB1 and their downstream target genes. Results: RNA-seq results showed that target genes regulated by CRL4B complex involved in a number of malignant tumor-related signaling pathways. qRT-PCR results verified that the mRNA expression levels of the target genes of CUL4B or DDB1 knockdown groups were higher than those of the control group, and the difference was statistically significant (P<0.05). ChIP-PCR results showed that CRL4B complex directly bound to the promoter regions of the target genes, NME1 and SFRP1, and the enrichment of monoubiquitination of lysine at 119 of histone H2A (H2AK119ub1) in the promoter region of target gene was reduced after CUL4B knockdown. The proliferation rate in PANC-1 cell line of the control group was (32.10±3.58)%, higher than (13.95±1.66)% in the shCUL4B group and (22.38±0.77)% in the shCUL4B+ siSFRP1 group (P<0.05). The proliferation rate in AsPC-1 cell line of the control group was (35.47±7.80)%, higher than (19.60±3.58)% in the shCUL4B group and (30.09±0.81)% in the shCUL4B+ siSFRP1 group (P<0.05). The scratch repair experiment showed that the migration rate of PANC-1 cell line control group was (53.18±3.70)%, higher than that (17.46±2.62)% in the shCUL4B group and (44.99±9.18)% in the shCUL4B + siSFRP1 group (P<0.05). Western blot showed the expression levels of epithelial markers including α-catenin and γ-catenin in the control group were 1.00±0.03 and 1.01±0.11, respectively, lower than 1.44±0.01 and 1.21±0.06 in the shCUL4B group (P<0.05). The expression levels of mesenchymal markers including fibronectin and vimentin in the control group were 1.01±0.14 and 1.02±0.18, respectively, higher than 1.53±0.13 and 1.22±0.07 in the shCUL4B+ siSFRP1 group (P<0.05). The cell metastasis rate of the control group was (100.00±3.96)%, higher than the (35.49±0.34)% in the shCUL4B group and (107.06±2.77)% in the shCUL4B+ siSFRP1 group, the difference was statistically significant (P<0.05). The expressions of CUL4B and DDB1 were significantly upregulated in the pancreatic cancer tissues, and were negatively correlated with the expression of SFRP1 (r=-0.342 and r=-0.264, respectively). Conclusions: CRL4B complex inhibits the transcription of target gene SFRP1 and promotes the development of pancreatic cancer. Moreover, CRL4B complex is upregulated in pancreatic cancer, which provide a potential of therapeutic target for pancreatic cancer.

Elevated Alu retroelement copy number among workers exposed to diesel engine exhaust

BACKGROUND

Millions of workers worldwide are exposed to diesel engine exhaust (DEE), a known genotoxic carcinogen. Alu retroelements are repetitive DNA sequences that can multiply and compromise genomic stability. There is some evidence linking altered Alu repeats to cancer and elevated mortality risks. However, whether Alu repeats are influenced by environmental pollutants is unexplored. In an occupational setting with high DEE exposure levels, we investigated associations with Alu repeat copy number.

METHODS

A cross-sectional study of 54 male DEE-exposed workers from an engine testing facility and a comparison group of 55 male unexposed controls was conducted in China. Personal air samples were assessed for elemental carbon, a DEE surrogate, using NIOSH Method 5040. Quantitative PCR (qPCR) was used to measure Alu repeat copy number relative to albumin (Alb) single-gene copy number in leucocyte DNA. The unitless Alu/Alb ratio reflects the average quantity of Alu repeats per cell. Linear regression models adjusted for age and smoking status were used to estimate relations between DEE-exposed workers versus unexposed controls, DEE tertiles (6.1-39.0, 39.1-54.5 and 54.6-107.7 µg/m³) and Alu/Alb ratio.

RESULTS

DEE-exposed workers had a higher average Alu/Alb ratio than the unexposed controls (p=0.03). Further, we found a positive exposure-response relationship (p=0.02). The Alu/Alb ratio was highest among workers exposed to the top tertile of DEE versus the unexposed controls (1.12±0.08 SD vs 1.06±0.07 SD, p=0.01).

CONCLUSION

Our findings suggest that DEE exposure may contribute to genomic instability. Further investigations of environmental pollutants, Alu copy number and carcinogenesis are warranted.

Risk of Acute Lung Injury after Esophagectomy

To develop a new approach for identifying acute lung injury (ALI) in surgical ward setting and to assess incidence rate, clinical outcomes, and risk factors for ALI cases after esophagectomy. We also compare the degree of lung injury between operative and non-operative sides. Consecutive esophageal cancer patients (n=1022) who underwent esophagectomy from Dec 2012 to Nov 2018 in our hospital were studied. An approach for identifying ALI was proposed that integrated radiographic assessment of lung edema (RALE) score to quantify degree of lung edema. Stepwise logistic regression identified risk factors for postoperative ALI incidence. The degree of bilateral lung injury was compared using the RALE score. The approach for identifying ALI in surgical ward setting was defined as acute onset, PaO₂/FiO₂≤300 mmHg, bilateral opacities on bedside chest radiograph with a RALE score≥16, and exclusion of cardiogenic pulmonary edema. Incidence rate of ALI was estimated to be 9.7%. ALI diagnosis was associated with multiple clinical complications, prolonged hospital stay, higher medical bills, and higher perioperative mortality. Nine risk factors including BMI, ASA class, DLCO%, duration of surgery, neutrophil percentage, high-density lipoprotein, and electrolyte disorders were identified. The RALE score of the lung lobes of the operative side was higher than the non-operative side. A new approach for identifying ALI in esophageal cancer patients receiving esophagectomy was proposed and several risk factors were identified. ALI is common and has severe outcomes. The lung lobes on the operative side are more likely to be affected than the non-operative side.

Chronic exposure to diesel exhaust may cause small airway wall thickening without lumen narrowing: a quantitative computerized tomography study in Chinese diesel engine testers

Background

Diesel exhaust (DE) is a major source of ultrafine particulate matters (PM) in ambient air and contaminates many occupational settings. Airway remodeling assessed using computerized tomography (CT) correlates well with spirometry in patients with obstructive lung diseases. Structural changes of small airways caused by chronic DE exposure is unknown. Wall and lumen areas of 6th and 9th generations of four candidate airways were quantified using end-inhalation CT scans in 78 diesel engine testers (DET) and 76 non-DETs. Carbon content in airway macrophage (CCAM) in sputum was quantified to assess the dose-response relationship.

Results

Environmental monitoring and CCAM showed a much higher PM exposure in DETs, which was associated with higher wall area and wall area percent for 6th generation of airways. However, no reduction in lumen area was identified. No study subjects met spirometry diagnosis of airway obstruction. This suggested that small airway wall thickening without lumen narrowing may be an early feature of airway remodeling in DETs. The effect of DE exposure status on wall area percent did not differ by lobes or smoking status. Although the trend test was of borderline significance between categorized CCAM and wall area percent, subjects in the highest CCAM category has a 14% increase in wall area percent for the 6th generation of airways compared to subjects in the lowest category. The impact of DE exposure on FEV1 can be partially explained by the wall area percent with mediation effect size equal to 20%, P_perm = 0.028).

Conclusions

Small airway wall thickening without lumen narrowing may be an early image feature detected by CT and underlie the pathology of lung injury in DETs. The pattern of changes in small airway dimensions, i.e., thicker airway wall without lumen narrowing caused by occupational DE exposure was different to that (i.e., thicker airway wall with lumen narrowing) seen in our previous study of workers exposed to nano-scale carbon black aerosol, suggesting constituents other than carbon cores may contribute to such differences. Our study provides some imaging indications of the understanding of the pulmonary toxicity of combustion derived airborne particulate matters in humans.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12989-021-00406-1.

Quantitative CT Analysis of Small Airway Remodeling in Patients with Chronic Obstructive Pulmonary Disease by a New Image Post-Processing System

Purpose

To explore a practical marker for quantitatively analyzing the small airway remodeling in COPD by HRCT.

Patients and Methods

Twenty-four patients with COPD (GOLD I, n = 7; GOLD II, n = 8; GOLD III+IV, n = 9) and 14 healthy controls (7 normal pulmonary function; 7 small-airway disease (SAD)) were enrolled in the study as five groups, GOLD I, GOLD II, GOLD III+IV, normal and SAD. All subjects underwent HRCT and spirometry. With ISP 9.0, whole emphysema index (EI) and the airway parameters, including wall area (WA), lumen area (LA), airway area (AA) of the 3rd, 5th and 9th generations of bronchi, were measured successively. The ratio of LA/AA and WA/AA in the 3rd, 5th and 9th generations of bronchi were calculated and compared among groups.

Results

For the five groups, EI was increased only in GOLD III+IV group (P < 0.05), while the ratio of LA/AA (9-LA/AA) and WA/AA (9-WA/AA) in 9th generation of bronchi have significantly changed since SAD group (P < 0.05). There were significant correlation between FEV₁generations of bronchi (r3 = 0.429, r5 = 0.583, r9 = 0.592, respectively, P < 0.05); FEV₁% and WA/AA (r3 = –0.428, r5 = –0.532, r9 = –0.570, respectively, P < 0.05); as well as MMEF% and LA/AA (r3 = 0.421, r5 = 0.566, r9 = 0.610, respectively, P < 0.05); MMEF% and WA/AA (r3 = –0.421, r5 = –0.529, r9 = –0.593, respectively, P < 0.05).

Conclusion

Small airway remodeling has occurred in the early stage of COPD, while emphysema in the late stage of COPD. The 9-LA/AA and 9-WA/AA are accurate and practical markers for small airway remodeling of COPD.

Smoke Chemistry, In Vitro Cytotoxicity, and Genotoxicity Demonstrates Enhanced Toxicity of Cigarillos Compared With Cigarettes

There has been limited toxicity testing of cigarillos, including comparison to cigarettes. This study compared the smoke chemistry and the cytotoxic and genotoxic potential of 10 conventional cigarettes and 10 cigarillos based on the greatest market share. Whole smoke and total particulate matter (TPM) were generated using the Canadian Intense and International Organization for Standardization puffing protocols. Tobacco-specific nitrosamines, carbonyls, and polycyclic aromatic hydrocarbons were measured using gas chromatography-mass spectrometry. TPM smoke extracts were used for the in vitro assays. Cytotoxicity was assessed in human bronchial epithelial continuously cultured cell line cells using the neutral red uptake assay. Genotoxic potential was assessed using the micronucleus (human lung adenocarcinoma continuously cultured cell line cells), Ames, and thymidine kinase assays. TPM from all cigarillos tested was more cytotoxic than cigarettes. Micronucleus formation was significantly greater for cigarillos compared with cigarettes at the highest dose of TPM, with or without rat liver S9 fraction. In the Ames test +S9, both tobacco products exhibited significant dose-dependent increases in mutation frequency, indicating metabolic activation is required for genotoxicity. In the thymidine kinase assay +S9, cigarillos showed a significantly enhanced mutation frequency although both tobacco products were positive. The levels of all measured polycyclic aromatic hydrocarbons, tobacco-specific nitrosamines, and carbonyls (except acrolein) were significantly greater in cigarillos than cigarettes. The Canadian Intense puffing protocol demonstrated increased smoke constituent levels compared with International Organization for Standardization. Even though the gas vapor phase was not tested, the results of this study showed that under the tested conditions the investigated cigarillos showed greater toxicity than comparator cigarettes. This study found that there is significantly greater toxicity in the tested U.S. marketed cigarillos than cigarettes for tobacco constituent levels, cytotoxicity, and genotoxicity. These findings are important for understanding the human health toxicity from the use of cigarillos relative to cigarettes and for building upon knowledge regarding harm from cigarillos to inform risk mitigation strategies.

Ambient particulate matter compositions and increased oxidative stress: Exposure-response analysis among high-level exposed population

BACKGROUND

Oxidative stress has been suggested to be one of the key drivers of health impact of particulate matter (PM). More studies on the oxidative potential of PM alone, but fewer studies have comprehensively evaluated the effects of external and internal exposure to PM compositions on oxidative stress in population.

OBJECTIVE

To comprehensively investigate the exposure-response relationship between PM and its main compositions with oxidative stress indicators.

METHODS

We conducted a cross-sectional study including 768 participants exposed to particulates. Environmental levels of fine particulate matter (PM_2.5), polycyclic aromatic hydrocarbons (PAHs) and metals in PM were measured, and urinary levels of PAHs metabolites and metals were measured as internal dose, respectively. Multivariable linear regression models were used to analyze the correlations of PM exposure and urinary levels of 8-hydroxy-2́'-deoxyguanosine (8-OHdG), and 8-iso-prostaglandin-F2α (8-iso-PGF2α) and malondialdehyde (MDA).

RESULTS

The concentration of both PM_2.5 and total PAHs was significantly correlated with increased urinary 8-OHdG, 8-iso-PGF2α and MDA levels (all p < 0.05). The levels of 4 essential metals all showed significant exposure-response increase in urinary 8-OHdG in both current and non-current smokers (all p < 0.05); ambient selenium, cobalt and zinc were found to be significantly correlated with urinary 8-iso-PGF2α (p = 0.002, 0.003, 0.01, respectively); only selenium and cobalt were significantly correlated with urinary MDA (p < 0.001, 0.01, respectively). Furthermore, we found each one-unit increase in urinary total OH-PAHs generated a 0.32 increase in urinary 8-OHdG, a 0.22 increase in urinary 8-iso-PGF2α and a 0.19 increase in urinary MDA (all p < 0.001). Furthermore, it was found that the level of 12 urinary metals all showed significant and positive correlations with three oxidative stress biomarkers in all subjects (all p < 0.001).

CONCLUSIONS

Our systematic molecular epidemiological study showed that particulate matter components could induce increased oxidative stress on DNA and lipid. It may be more important to monitor and control the harmful compositions in PM rather than overall particulate mass.

Ambient air pollutants and hospital visits for pneumonia: a case-crossover study in Qingdao, China

Background

Pneumonia is one of the principal reasons for incidence and death in the world. The former research mainly concentrated on specific sources of patients. Besides, due to the heterogeneity among regions, there are inconsistencies in the outcome of these surveys. To explore the relationship between atmospheric pollution and hospital visits for pneumonia under the climate and pollution conditions in Qingdao, we carried out this study.

Methods

The medical records of pneumonia patients were gathered from the affiliated hospital of Qingdao University during Jan 1st, 2014, and Dec 31st,2018. Daily concentrations of PM_2.5, PM₁₀, SO₂, NO₂, as well as CO, were collected from the national air quality monitoring stations in Qingdao. Case-crossover study design and conditional logistic regression model were used to estimate the associations. Daily temperature, relative humidity, and atmospheric pressure were adjusted as the covariates in all models. A principal component analysis was used to solve the multicollinearity between atmospheric pollutants and investigate the relationship between various air pollutants and pneumonia occurs.

Results

In the single pollutant model, with interquartile range increment of the density of PM_2.5, PM₁₀, NO₂ and SO₂ at the lag2 days, the odds ratio of hospital visits for pneumonia patients increased by 6.4% (95%CI, 2.3–10.7%), 7.7% (95%CI, 3.2–12.4%), 6.7% (95%CI, 1.0–12.7%), and 7.2% (95%CI, 1.1–13.5%). Stratified analysis showed that pollutants were more significant in the cold period. Besides, the impact of atmospheric particulates on different ages mainly occurs in the young child (0 to 3-year-old). The odds ratio was 1.042 (95%CI, 1.012–1.072) when the principal components of atmospheric pollutants were included in the conditional logistic model.

Conclusions

Our study found a significant relationship between short-term uncovering to PM_2.5, PM₁₀, NO₂, SO₂, and hospital visits for pneumonia in Qingdao. The effect of atmospheric pollutants mainly arose in a cold period. The particulate matter might be the principal reason in inducing hospital visits for pneumonia.

Mechanical stimuli for left ventricular growth during pressure overload

BACKGROUND

The mechanical stimulus (i.e. stress or stretch) for growth occurring in the pressure-overloaded left ventricle (LV) is not exactly known.

OBJECTIVE

To address this issue, we investigate the correlation between local ventricular growth (indexed by local wall thickness) and the local acute changes in mechanical stimuli after aortic banding.

METHODS

LV geometric data were extracted from 3D echo measurements at baseline and 2 weeks in the aortic banding swine model (n = 4). We developed and calibrated animal-specific finite element (FE) model of LV mechanics against pressure and volume waveforms measured at baseline. After the simulation of the acute effects of pressure-overload, the local changes of maximum, mean and minimum myocardial stretches and stresses in three orthogonal material directions (i.e., fiber, sheet and sheet-normal) over a cardiac cycle were quantified. Correlation between mechanical quantities and the corresponding measured local changes in wall thickness was quantified using the Pearson correlation number (PCN) and Spearman rank correlation number (SCN).

RESULTS

At 2 weeks after banding, the average septum thickness decreased from 10.6 ± 2.92mm to 9.49 ± 2.02mm, whereas the LV free-wall thickness increased from 8.69 ± 1.64mm to 9.4 ± 1.22mm. The FE results show strong correlation of growth with the changes in maximum fiber stress (PCN = 0.5471, SCN = 0.5111) and changes in the mean sheet-normal stress (PCN= 0.5266, SCN = 0.5256). Myocardial stretches, however, do not have good correlation with growth.

CONCLUSION

These results suggest that fiber stress is the mechanical stimuli for LV growth in pressure-overload.

Alternative Applications of Genotyping Array Data Using Multivariant Methods

One of the forerunners that pioneered the revolution of high-throughput genomic technologies is the genotyping microarray technology, which can genotype millions of single-nucleotide variants simultaneously. Owing to apparent benefits, such as high speed, low cost, and high throughput, the genotyping array has gained lasting applications in genome-wide association studies (GWAS) and thus accumulated an enormous amount of data. Empowered by continuous manufactural upgrades and analytical innovation, unconventional applications of genotyping array data have emerged to address more diverse genetic problems, holding promise of boosting genetic research into human diseases through the re-mining of the rich accumulated data. Here, we review several unconventional genotyping array analysis techniques that have been built on the idea of large-scale multivariant analysis and provide empirical application examples. These unconventional outcomes of genotyping arrays include polygenic score, runs of homozygosity (ROH)/heterozygosity ratio, distant pedigree computation, and mitochondrial DNA (mtDNA) copy number inference.

Occupational exposure to carbon black nanoparticles increases inflammatory vascular disease risk: an implication of an ex vivo biosensor assay

Background

Among manufactured or engineered nanoparticles, carbon black (CB) has largest production worldwide and is also an occupational respiratory hazard commonly seen in rubber industry. Few studies have assessed the risk for cardiovascular disease in carbon black exposed populations. An endothelial biosensor assay was used to quantify the capacity of sera from 82 carbon black packers (CBP) and 106 non-CBPs to induce endothelial cell activation ex vivo. The mediation effect of circulatory proinflammatory factors on the association between carbon black exposure and endothelial cell activation was assessed and further validated using in vitro intervention experiments.

Results

The average elemental carbon level inside carbon black bagging facilities was 657.0 μg/m³, which was 164-fold higher than that seen in reference areas (4.0 μg/m³). A global index was extracted from mRNA expression of seven candidate biosensor genes using principal component analysis and used to quantify the magnitude of endothelial cell activation. This global index was found to be significantly altered in CBPs compared to non-CBPs (P < 0.0001), however this difference did not vary by smoking status (P = 0.74). Individual gene analyses identified that de novo expression of key adhesion molecules (e.g., ICAM and VCAM) and chemotactic factors (e.g., CCL2, CCL5, and CXCL8) responsible for the recruitment of leukocytes was dramatically induced in CBPs with CXCL8 showing the highest fold of induction (relative quantification = 9.1, P < 0.0001). The combination of mediation analyses and in vitro functional validation confirmed TNF-α, IL-1β, and IL-6 as important circulatory factors mediating the effects of carbon black exposure on endothelial cell activation responses.

Conclusions

Inflammatory mediators in sera from CBPs may bridge carbon black exposure and endothelial cell activation response assessed ex vivo. CBPs may have elevated risk for cardiovascular diseases when comorbidity exists. Our study may serve as a benchmark for understanding health effects of engineered carbon based nanoparticles with environmental and occupational health relevance.

Use of artificial intelligence in computed tomography dose optimisation

The field of artificial intelligence (AI) is transforming almost every aspect of modern society, including medical imaging. In computed tomography (CT), AI holds the promise of enabling further reductions in patient radiation dose through automation and optimisation of data acquisition processes, including patient positioning and acquisition parameter settings. Subsequent to data collection, optimisation of image reconstruction parameters, advanced reconstruction algorithms, and image denoising methods improve several aspects of image quality, especially in reducing image noise and enabling the use of lower radiation doses for data acquisition. Finally, AI-based methods to automatically segment organs or detect and characterise pathology have been translated out of the research environment and into clinical practice to bring automation, increased sensitivity, and new clinical applications to patient care, ultimately increasing the benefit to the patient from medically justified CT examinations. In summary, since the introduction of CT, a large number of technical advances have enabled increased clinical benefit and decreased patient risk, not only by reducing radiation dose, but also by reducing the likelihood of errors in the performance and interpretation of medically justified CT examinations.

Real-ambient exposure to air pollution exaggerates excessive growth of adipose tissue modulated by Nrf2 signal

Air pollution was becoming a global threat to the public health, which was primarily mediated by PM_2.5 induced cardiovascular diseases and pulmonary diseases. Recently, observational epidemiologic studies proposed the link between PM_2.5 and obesity. Consistently, the link was also supported by limited animal researches. However, the potential mechanism mediating the harmful effects of PM_2.5 was still elusive. In this study, we applied the "real-ambient exposure" system to conduct the experiments, which was closer to the status of ambient air pollution compared with the method of intratracheal instillation and concentrated air particles (CAPs) exposure system. Nuclear factor E2-related factor 2 (Nrf2) was previously reported to protect against inflammation and oxidative stress when exposed to PM_2.5. Here, we reported that Nrf2^-/- mice developed overgrowth of adipose tissue after "real-ambient exposure" to PM_2.5, compared to filtered air (FA) group. Consistently, compared to FA group, adipocytes from subcutaneous (sWAT) and gonadal (gWAT) white adipose tissue of Nrf2^-/- mice exhibited enlarged cell size in PM_2.5 exposure group. Furthermore, the levels of high-density lipoprotein (HDL) and low-density lipoprotein (LDL) in serum and liver of Nrf2^-/- mice were also altered statistically in PM_2.5 exposure group. Importantly, when the expression of lipogenic enzymes was analyzed, the levels of the related specific genes in adipose tissue and liver of Nrf2^-/- mice were altered in PM_2.5 exposure group. Interestingly, the key transcription factors modulating expression of lipogenic enzymes in liver of Nrf2^-/- mice were also found altered in PM_2.5 exposure group, such as peroxisome proliferator-activated receptor (PPARα, PPARγ). Taken together, our study mimicked the status of ambient air pollution, revealed new insights into the adverse effect of PM_2.5 exposure, provided new link between air pollution and overgrowth of adipose tissue, and supported the vital role of Nrf2 in mediating the side effects of PM_2.5.

Association between air pollution and lung development in schoolchildren in China

Background

China has been facing nationwide air pollution at unprecedented high levels primarily from fossil–fuel combustion in the past decade. However, few studies have been conducted on the adverse effect of severe air pollution on lung development in school-age children.

Methods

Using wellness check and air pollution data from 2014 to 2017, we conducted a retrospective analysis of lung development in 21 616 school-age children from Shijiazhuang and Qingdao from North China with severe vs mild air pollution. Linear mixed effects model was performed to assess the effect of air pollution on forced vital capacity (FVC) growth.

Results

Exposure to severe air pollution was associated with a dramatic reduction in annual FVC growth rate (−71.3 mL,  p< 0.001). In addition, every 10 μg/m³ increase in annual PM_2.5 level was associated with a reduction of annual FVC growth by 12.2 mL ( p< 0.001). Sex discrepancy (boys vs girls) in FVC growth was greater in Qingdao (35.4 mL/year, 95% CI: 26.0 to 44.7) than in Shijiazhuang (19.8 mL/year, 95% CI: 9.3 to 30.3) (p for interaction=0.063). Exposure to indoor coal- or wood-burning stove heating (−79.4 mL,  p< 0.001) and secondhand smoke at home (−59.3 mL,  p= 0.003) were inversely associated with FVC growth.

Conclusion

Our study raised serious alarm over the threat of severe air pollution to lung development in school-age children. Sex discrepancy in lung development was reduced dramatically in heavily polluted area.

Carbon content in airway macrophages and genomic instability in Chinese carbon black packers

Carbon black (CB) particulates as virtually pure elemental carbon can deposit deep in the lungs of humans. International Agency for Research on Cancer classified CB as a Group 2B carcinogen due to inconclusive human evidence. A molecular epidemiological study was conducted in an established cohort of CB packers (CBP) to assess associations between CB exposure and genomic instability in peripheral lymphocytes using cytokinesis-block micronucleus assay (CBMN). Carbon content in airway macrophages (CCAM) was quantified as a bio-effective dosimeter for chronic CB exposure. Dose-response observed in CBPs was compared to that seen in workers exposed to diesel exhaust. The association between CB exposure status and CBMN endpoints was identified in 85 CBPs and 106 non-CBPs from a 2012 visit and replicated in 127 CBPs and 105 non-CBPs from a 2018 visit. The proportion of cytoplasm area occupied by carbon particles in airway macrophages was over fivefold higher in current CBPs compared to non-CBPs and was associated with CBMN endpoints in a dose-dependent manner. CB aerosol and diesel exhaust shared the same potency of inducing genomic instability in workers. Circulatory pro-inflammatory factors especially TNF-α was found to mediate associations between CB exposure and CBMN endpoints. In vitro functional validation supported the role of TNF-α in inducing genomic instability. An estimated range of lower limits of benchmark dose of 4.19-7.28% of CCAM was recommended for risk assessment. Chronic CB exposure increased genomic instability in human circulation and this provided novel evidence supporting its reclassification as a human carcinogen.