Exposure to polycyclic aromatic hydrocarbons, volatile organic compounds, and tobacco-specific nitrosamines and incidence of esophageal cancer

BACKGROUND

Studying carcinogens in tobacco and nontobacco sources may be key to understanding the pathogenesis and geographic distribution of esophageal cancer.

METHODS

The Golestan Cohort Study has been conducted since 2004 in a region with high rates of esophageal squamous cell carcinoma. For this nested study, the cases comprised of all incident cases by January 1, 2018; controls were matched to the case by age, sex, residence, time in cohort, and tobacco use. We measured urinary concentrations of 33 exposure biomarkers of nicotine, polycyclic aromatic hydrocarbons, volatile organic compounds, and tobacco-specific nitrosamines. We used conditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals for associations between the 90th vs the 10th percentiles of the biomarker concentrations and incident esophageal squamous cell carcinoma.

RESULTS

Among individuals who did not currently use tobacco (148 cases and 163 controls), 2 acrolein metabolites, 2 acrylonitrile metabolites, 1 propylene oxide metabolite, and one 1,3-butadiene metabolite were significantly associated with incident esophageal squamous cell carcinoma (adjusted odds ratios between 1.8 and 4.3). Among tobacco users (57 cases and 63 controls), metabolites of 2 other volatile organic compounds (styrene and xylene) were associated with esophageal squamous cell carcinoma (OR = 6.2 and 9.0, respectively). In tobacco users, 2 tobacco-specific nitrosamines (NNN and N'-Nitrosoanatabine) were also associated with esophageal squamous cell carcinoma. Suggestive associations were seen with some polycyclic aromatic hydrocarbons (especially 2-hydroxynaphthalene) in nonusers of tobacco products and other tobacco-specific nitrosamines in tobacco users.

CONCLUSION

These novel associations based on individual-level data and samples collected many years before cancer diagnosis, from a population without occupational exposure, have important public health implications.

[Correlation analysis between Pirani score and talo-navicular angle,calcaneo-cuboid angle and tibio-calcaneall angle of infant clubfoot under ultrasound]

Objective: To explore the evaluation effect of ultrasonography and Pirani score on tarsal deformity, treatment effect and pseudo-correction of congenital clubfoot in infants and young children, and the correlation between the two methods. Methods: This is a retrospective case series study. The clinical data of 26 children (40 feet) with congenital clubfoot who were evaluated by ultrasonography in the Third Affiliated Hospital of Zhengzhou University from January 2020 to January 2023 were retrospectively collected. There were 16 males and 10 females. The age at the first ultrasound examination was (M(IQR)) 9.0 (18.0) days (range: 1 to 46 days). All patients were treated with Ponseti method by the same physician. The Pirani scores before and after treatment and at the last examination, and the talonavicular angle, calcaneocuboid angle and tibiocalcaneal angle measured by ultrasound were collected, and the treatment and follow-up were recorded. Paired sample t test, repeated measures analysis of variance or Kruskal-Wallis test were used for data comparison, and Spearman correlation analysis was used for correlation analysis. The receiver operating characteristic curve was used to calculate the efficacy of ultrasound in evaluating different Pirani scores. Results: The number of plaster fixation in 26 children was 4.0 (1.0) times (range: 2 to 8 times). The medial talonavicular angle and posterior tibiocalcaneal angle were significantly improved after treatment and at the last follow-up compared with those before treatment, and the differences were statistically significant (all P<0.01). There was no difference in lateral calcaneocuboid angle before and after treatment and at the last follow-up (F=1.971, P>0.05). Pseudo-correction occurred in 2 cases (2 feet) during the treatment, with an incidence of 5%. Correlation analysis showed that there was a moderate positive correlation between talonavicular angle and Pirani midfoot score (r=0.480, P<0.01). There was no correlation between calcaneocuboid angle and Pirani midfoot score (r=0.114, P=0.105). There was a moderate negative correlation between tibial heel angle and Pirani hindfoot score (r=-0.566, P<0.01). The cut-off point of Pirani midfoot score of 1.5 was 38.78°, the sensitivity was 0.90, the specificity was 0.56, and the area under the curve was 0.75. The cut-off value of angle was 27.51 °, the sensitivity was 0.16, the specificity was 0.92, and the area under the curve was 0.44.The cut-off points of Pirani midfoot score of 3.0 were 45.08°and 9.96°, the sensitivity was 0.94 and 0.91, the specificity was 0.37 and 0.42, and the area under the curve was 0.59 and 0.62, respectively. The cut-off values of Pirani hindfoot score of 2.0 and 3.0 were 167.46° and 160.15°, respectively. The sensitivity was 0.75 and 0.67, the specificity was 0.81 and 0.83, and the area under the curve was 0.78 and 0.71, respectively. Conclusion: Ultrasound can complement with Pirani score, visually and dynamically observe the morphology and position changes of talonavicular joint, calcaneocuboid joint and tibiotalocalcaneal joint, monitor the recovery and pseudo-correction of tarsal bones, and better evaluate the therapeutic effect.

Influence of Half-life and Smoking/Nonsmoking Ratio on Biomarker Consistency between Waves 1 and 2 of the Population Assessment of Tobacco and Health Study

BACKGROUND

Biomarkers of exposure are tools for understanding the impact of tobacco use on health outcomes if confounders like demographics, use behavior, biological half-life, and other sources of exposure are accounted for in the analysis.

METHODS

We performed multiple regression analysis of longitudinal measures of urinary biomarkers of alkaloids, tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons, volatile organic compounds (VOC), and metals to examine the sample-to-sample consistency in Waves 1 and 2 of the Population Assessment of Tobacco and Health (PATH) Study including demographic characteristics and use behavior variables of persons who smoked exclusively. Regression coefficients, within- and between-person variance, and intra-class correlation coefficients (ICC) were compared with biomarker smoking/nonsmoking population mean ratios and biological half-lives.

RESULTS

Most biomarkers were similarly associated with sex, age, race/ethnicity, and product use behavior. The biomarkers with larger smoking/nonsmoking population mean ratios had greater regression coefficients related to recency of exposure. For VOC and alkaloid metabolites, longer biological half-life was associated with lower within-person variance. For each chemical class studied, there were biomarkers that demonstrated good ICCs.

CONCLUSIONS

For most of the biomarkers of exposure reported in the PATH Study, for people who smoke cigarettes exclusively, associations are similar between urinary biomarkers of exposure and demographic and use behavior covariates. Biomarkers of exposure within-subject consistency is likely associated with nontobacco sources of exposure and biological half-life.

IMPACT

Biomarkers measured in the PATH Study provide consistent sample-to-sample measures from which to investigate the association of adverse health outcomes with the characteristics of cigarettes and their use.

AI's deep dive into complex pediatric inguinal hernia issues: a challenge to traditional guidelines?

OBJECTIVE

This study utilized ChatGPT, an artificial intelligence program based on large language models, to explore controversial issues in pediatric inguinal hernia surgery and compare its responses with the guidelines of the European Association of Pediatric Surgeons (EUPSA).

METHODS

Six contentious issues raised by EUPSA were submitted to ChatGPT 4.0 for analysis, for which two independent responses were generated for each issue. These generated answers were subsequently compared with systematic reviews and guidelines. To ensure content accuracy and reliability, a content analysis was conducted, and expert evaluations were solicited for validation. Content analysis evaluated the consistency or discrepancy between ChatGPT 4.0's responses and the guidelines. An expert scoring method assess the quality, reliability, and applicability of responses. The TF-IDF model tested the stability and consistency of the two responses.

RESULTS

The responses generated by ChatGPT 4.0 were mostly consistent with the guidelines. However, some differences and contradictions were noted. The average quality score was 3.33, reliability score was 2.75, and applicability score was 3.46 (out of 5). The average similarity between the two responses was 0.72 (out of 1), Content analysis and expert ratings yielded consistent conclusions, enhancing the credibility of our research.

CONCLUSION

ChatGPT can provide valuable responses to clinical questions, but it has limitations and requires further improvement. It is recommended to combine ChatGPT with other reliable data sources to improve clinical practice and decision-making.

Willingness to receive and recommend hypothetical mpox vaccination and associated factors in Chinese adults: a community-based survey in Shenzhen, China

OBJECTIVES

China may face new threats to public health due to the increased risk of imported mpox (monkeypox) cases. However, research gaps exist in the acceptance of mpox vaccination and potential associated factors in the Chinese population.

STUDY DESIGN

We conducted a cross-sectional study targeting community residents in Shenzhen, China, from August 5 to September 7 2022.

METHODS

A self-administered questionnaire was used to collect information about demographic and health characteristics, mpox-related perceptions, and attitudes towards mpox vaccination. Multivariable logistic regression models were applied to detect the factors associated with willingness to receive and recommend mpox vaccination.

RESULTS

A total of 2293 community residents were included in the analyses (average age: 34.03, female: 72.6%). Among the participants, 76.9% were aware of mpox, 62.1% were aware of the global mpox outbreak, but only 53.6% had a high knowledge level of mpox. Males had a higher proportion of high knowledge (56.9% vs 52.3%, P＜0.05) and a lower proportion of high worry (30.2% vs 45.4%, P＜0.05) than females. Approximately 69.1% of the participants were willing to vaccinate against mpox, and 69.6% were willing to recommend mpox vaccination to people around them, in which no gender difference was found. The obstacle reported most among people hesitant to receive vaccination was concerning the safety and side-effects, whereas it changed to be concerning the suitability due to individual health differences among people hesitant to recommend mpox vaccines. Factors associated with the willingness to receive and recommend mpox vaccination included having a history of influenza vaccination, having a history of COVID-19 vaccination, being aware of the global mpox outbreak, having a high knowledge level of mpox, and having a high level of mpox-related worry.

CONCLUSIONS

This study identified a moderate willingness to receive and recommend mpox vaccination among Chinese adults. Without gender differences, willingness to receive and recommend mpox vaccination was significantly associated with mpox-related perceptions, such as awareness, knowledge, and worry. Authoritative and up-to-date information is needed to help the general population improve public confidence in mpox vaccines in China.

[Identification model of tooth number abnormalities on pediatric panoramic radiographs based on deep learning]

Objective: To identify tooth number abnormalities on pediatric panoramic radiographs based on deep learning. Methods: Eight hundred panoramic radiographs of children aged 4 to 11 years meeting the inclusion and exclusion criteria were selected and randomly assigned by writing programs in Python (version 3.9) to the training set (480 images), verification set (160 images) and internal test set (160 images), taken in Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology between November 2012 to August 2020. And all panoramic radiographs of children aged 4 to 11 years taken in the First Outpatient Department of Peking University School and Hospital of Stomatology from June 2022 to December 2022 were collected as the external test set (907 images). All of the 1 707 images were obtained by operators to determine the outline and to label the tooth position of each deciduous tooth, permanent tooth, permanent tooth germ and additional tooth. The deep learning model with ResNet-50 as the backbone network was trained on the training set, validated on the verification set, tested on the internal test set and external test set. The images of test sets were divided into two categories according to whether there was abnormality of tooth number, to calculate sensitivity, specificity, positive predictive value and negative predictive value, and then divided into four types of extra teeth and missing permanent teeth both existed, extra teeth existed only, missing permanent teeth existed only, and normal teeth number, to calculate Kappa values. Results: The sensitivity, specificity, positive predictive value and negative predictive value were 98.0%, 98.3%, 99.0% and 96.7% in the internal test set, and 97.1%, 98.4%, 91.9% and 99.5% in the external test set respectively, according to whether there was abnormality of tooth number. While images were divided into four types, the Kappa value obtained in the internal test set was 0.886, and that in the external test set was 0.912. Conclusions: In this study, a deep learning-based model for identifying abnormal tooth number of children was developed, which could identify the position of additional teeth and output the position of missing permanent teeth on the basis of identifying normal deciduous and permanent teeth and permanent tooth germs on panoramic radiographs, so as to assist in diagnosing tooth number abnormalities.

Up-Regulation of TCF21 Expression Reverses the Malignant Phenotype of Cancer-Associated Fibroblasts in Esophageal Squamous Cell Carcinoma

PURPOSE/OBJECTIVE(S)

Cancer-associated fibroblasts (CAFs), as one major component of tumor microenvironment (TME), are closely associated with tumor initiation and progression. Our previous studies have discovered that CAFs induced the resistance of esophageal squamous cell carcinoma (ESCC) cells to a variety of chemotherapeutic drugs such as cisplatin and paclitaxel. Furthermore, CAFs attenuated ionizing irradiation (IR)-induced cancer cells death by regulating DNA damage response. CAFs themselves are highly resistant to death stimuli due to enhanced antioxidant potential and DNA repair capacity. How to inhibit the malignant phenotype of CAFs is critically important for the radical treatment of ESCC.

MATERIALS/METHODS

By RNA-sequencing and DNA methylation analysis, the transcriptome and epigenome of CAFs and matched normal fibroblasts (NFs) have been integratively analyzed. By transfection of TCF21 cDNA plasmid, the expression of TCF21 in CAFs has been up-regulated. Using a cell counting kit and migration and invasion assay, the effect of TCF21 on the growth and migration and invasive ability of CAFs has been detected. Using immunofluorescence and flow cytometry (FCM) analysis and western blotting, the effect of TCF21 on the DNA damage repair and apoptotic death of CAFs following IR has been detected.

RESULTS

TCF21 is one of the top ten down-regulated genes in CAFs compared with NFs due to promoter methylation. Up-regulation of TCF21 expression inhibited the growth rate and migration and invasive ability of CAFs. The expression of α-SMA, as an indicator of CAFs activation, was down-regulated in CAFs which were transfected with TCF21 cDNA. Furthermore, when TCF21 cDNA was transfected into CAFs, IR-induced DNA damage was increased while DNA repair was inhibited in CAFs, suggesting that TCF21 was involved in DNA damage response of CAFs following IR. FCM analysis showed that up-regulation of TCF21 expression promoted IR-induced apoptotic death of CAFs.

CONCLUSION

TCF21 is a determinant of the malignant phenotype of CAFs in ESCC. Up-regulation of TCF21 expression is a promising approach of inhibiting the growth, migration and invasion, activation and radioresistance of CAFs in ESCC.

Hyperthermia Enhances the Radiosensitivity of Pancreatic Cancer Cells by Inhibiting Wnt2B Signaling

PURPOSE/OBJECTIVE(S)

Pancreatic cancer (PC) is a highly lethal human malignance. Due to unobvious symptoms at early stage, most of the patients with PC are diagnosed at late stages and lose the chance of surgical resection. Furthermore, PC patients are resistant to chemoradiotherapy and therefore show a dismal survival. Hyperthermia is commonly used as a sensitizer of chemotherapy or radiotherapy for the clinical treatment of human cancers. Our study aimed to investigate whether hyperthermia can improve the radiosensitivity of PC cells and uncover the involved mechanisms.

MATERIALS/METHODS

PC cells BxPC3, CFPAC-1 and PANC1 were heated to 43 ℃ 1 h before exposure to ionizing irradiation (IR). The radiosensitivity of PC cells were detected in vitro by colony formation assay, immunofluence analysis and western blotting. The mechanisms studies have been conducted using qRT-PCR analysis, cDNA/siRNA transfection and comet assay.

RESULTS

Hyperthermia significantly enhanced the radiosensitivity of PC cells by decreasing their colony formation and increasing DNA damage following IR. By qRT-PCR analysis of Wnt genes expressions, we found Wnt2B was significantly down-regulated in PC-3 cells which were treated with the combination of hyperthermia and IR compared with hyperthermia or IR alone. Functional assays showed that the expression level of Wnt2B was inversely associated with the radiosensitivity of PC-3 cells. Furthermore, we found hyperthermia inhibited the expression of DNA repair proteins such as p-BRCA1 and p-MRE11 in PC cells following IR CONCLUSION: Hyperthermia can significantly enhance the radiosensitivity of PC cells in a Wnt2B signaling-dependent manner.

Measurement of Direct-Photon Cross Section and Double-Helicity Asymmetry at sqrt[s]=510 GeV in p[over →]+p[over →] Collisions

We present measurements of the cross section and double-helicity asymmetry A_{LL} of direct-photon production in p[over →]+p[over →] collisions at sqrt[s]=510  GeV. The measurements have been performed at midrapidity (|η|<0.25) with the PHENIX detector at the Relativistic Heavy Ion Collider. At relativistic energies, direct photons are dominantly produced from the initial quark-gluon hard scattering and do not interact via the strong force at leading order. Therefore, at sqrt[s]=510  GeV, where leading-order-effects dominate, these measurements provide clean and direct access to the gluon helicity in the polarized proton in the gluon-momentum-fraction range 0.02<x<0.08, with direct sensitivity to the sign of the gluon contribution.

Clinical significance of extrathyroidal extension to major vessels in papillary thyroid carcinoma

PURPOSE

Gross extrathyroidal extension (gETE) into major vessel is considered the most advanced stage of the locally advanced papillary thyroid cancer (PTC). Surgical intervention may not benefit some patients at this disease stage or even result in intraoperative death due to massive hemorrhage; however, it is still considered an effective strategy for most cases. The lack of description for this challenging invasion in PTC warrants detailed characterization of its pattern, risk factors, optimal surgical method, and prognostic value.

METHODS

In total, 3127 patients diagnosed as having PTC were enrolled and categorized into two the following groups, namely the major vessel invasion (MVI) group (n = 30) and the control group (n = 3097). Data regarding clinicopathological and demographic characteristics, vascular invasion sites, postoperative complications, locoregional recurrence, distant metastasis, and surgical strategies were collected. Predictive disease-free survival (DFS) was also compared between the two groups.

RESULTS

MVI was independently associated with invasion of the esophageal extension, age < 55 years, tumor size > 1 cm, lateral lymph node metastasis, and distant metastasis (P = 0.00; P = 0.01; 0.05; P = 0.00; P = 0.00, respectively). The difference in the predictive DFS between the two groups was significant (P = 0.00), and the difference remained significant even in patients with ETE when compared with patients without ETE (P = 0.00). Additionally, predictive DFS did not differ significantly between patients who received vessel repairment and those who received vessel resection (P = 0.28).

CONCLUSIONS

This study first characterized the gross MVI pattern exhibited by PTC and the risk factors for MVI. Additionally, it demonstrated the DFS of patients with PTC. Extensive gross MVI significantly worsened the biological characteristics of PTC. Regardless of the high risk and difficulty of the operation, patients still benefited from the surgical intervention, and vessel repairment may be the optimal surgical strategy.

[Analysis of 2 diagnostic criteria of echocardiography for coronary artery aneurysm in Kawasaki disease]

Objective: To analyze the difference between Z score and previous criteria in the diagnosis characteristics of coronary artery aneurysm (CAA) in Kawasaki disease, and to investigate the clinical distribution of Kawasaki disease CAA in the Z score group. Methods: This study retrospectively analyzed the clinical and echocardiographic data of 2 419 children with Kawasaki disease in Shenzhen Children's Hospital from January 2009 to December 2019. The traditional criteria and Z score criteria were used to diagnose CAA, and the differences of diagnostic efficiency between the 2 diagnostic methods were analyzed. The clinical distribution characteristics of CAA in children with Kawasaki disease were analyzed by grouping their sex, clinical classification (complete Kawasaki disease, incomplete Kawasaki disease) the sensitivity to intravenous immunoglobulin (IVIG) (IVIG-sensitive Kawasaki disease,IVIG-unresponsive Kawasaki disease). And the course of the disease (≤6 weeks, >6-8 weeks, >8 weeks to 6 months) etc. The χ² test or Kruskal-Wallis test was used for comparison between the groups, and the Kappa test was used for consistency evaluation. Results: Among the 2 419 children with Kawasaki disease, 1 558 were males and 861 were females. The age of onset was 1.8 (1.0, 3.2) years. The rate of CAA by Z score criteria was higher than that by traditional method (21.9% (529/2 419) vs. 13.9% (336/2 419), χ²=1 074.94, P<0.001). Compared to the traditional method, the Z score criteria found higher rate of CAA in male patients, patients with incomplete Kawasaki disease, and IVIG-unresponsive patients (25.2% (392/1 558) vs. 16.0% (249/1 558), (32.7% (166/507) vs. 19.5% (99/507), 30.5% (95/312) vs. 24.0% (75/312), χ²=694.05, 216.19, 184.37, all P<0.001). The Z score criteria was consistent with the traditional method in diagnosing CAA (κ=0.642,P<0.001). Moreover, in the Z score criteria, the rate of CAA in males (25.2%, 392/1 558) was higher than that in females (15.9%, 137/861), higher in incomplete Kawasaki cases (32.7%, 166/507) than that in complete Kawasaki case (19.0%, 363/1 912), and higher in IVIG-unresponsive cases (30.4%, 95/312) than that in IVIG-sensitive cases (20.6%, 434/2 107), with statistically significant differences (χ²=27.76, 44.38, 15.43, all P<0.001). Coronary Z score of course ≤ 6 weeks was greater than that of course between>6-8 weeks and >8 weeks to 6 months (1.3 (0.7, 2.3) vs. 0.7 (0.3, 1.4), 0.7 (0.3, 1.3), Z=20.65, 13.70, both P<0.001). Conclusions: The rate of CAA in Kawasaki disease by Z score criteria is higher than that by traditional method. In the Z score group, most CAA occur within 6 weeks of the course of the disease, and the rate of CAA in male, incomplete Kawasaki disease, and IVIG-unresponsive is higher.

[Design of non-metallic crown for primary molars and analyzation of stress distribution: a finite element study]

Objectives: To study the design of nonmetallic crowns for deciduous molars by means of computer aided design and to analyze the key parameters of the nonmetallic crowns of deciduous molars using finite element method. Methods: The three-dimensional model of a mandibular second primary molar was constructed by using a micro-CT system. The thickness of the crown was limited to 0.5 mm and four different crown shapes (chamfer+anatomic, chamfer+non-anatomic, knife edge+anatomic and knife edge+non-anatomic) were designed. Then, the crown shape was limited as chamfer+non-anatomic and five different thicknesses of the crown (0.50, 0.75, 1.00, 1.25, 1.50 mm) were designed, and three different materials, including polyetherketoneketone (PEKK), polymethylmethacrylate (PMMA) resin and resin-infiltrated ceramic, were applied to make the crown. Stress distribution and fatigue of each component of the model under vertical and oblique loadings were analyzed by using finite element method. Non-axial retention analysis was performed on chamfer+non-anatomic crowns, made of PMMA resin, with thicknesses of 0.50, 0.75, 1.00, 1.25 and 1.50 mm. Results: Among the four crown shape designs, the chamfer+non-anatomic type crown showed the lowest von Mises stress and the highest safety factor. By comparing three different materials, the resin-infiltrated ceramic group showed obvious stress concentration on the buccal edge of the crown and the PEKK group showed stress concentration in the adhesive layer. Results of non-axial retention analysis showed that the torques required by the crowns with five thicknesses at the same rotation angle were as follows: 4 856.1, 4 038.1, 3 497.3, 3 256.3 and 3 074.3 N⋅m, respectively. The comparison of areas of the adhesives fracture among groups were as follows: 0.5 mm group < 0.75 mm group < 1.00 mm group < 1.25 mm group < 1.50 mm group. Conclusions: In the design of nonmetallic crowns for primary molars, the edge of the crown should be designed as chamfer, the shape of the inner crown should be non-anatomical and the minimum preparation amount of the occlusal surface should be 1.00 mm. Among the three materials, PMMA resin, of which elastic modulus is similar to the dentin and the dental adhesive, might be the most suitable material for the crowns of primary molars.

The long-term effect of dental treatment under general anaesthesia or physical restraints on children's dental anxiety and behaviour

AIM

Dental anxiety (DA) is a common problem worldwide because it renders dental treatment in children challenging. This study aimed to evaluate the long-term effect of dental treatment under general anaesthesia (GA) or physical restraints (PR) on children's DA and behaviour.

METHODS

A total of 103 children were recruited and divided into four groups: the GA group, PR group, cooperative (CO) group, and no experience (NE) group. The face version of the Modified Child Dental Anxiety Scale and modified Venham's Clinical Anxiety and Cooperative Behaviour Rating Scale were used to evaluate the level of DA and behaviour.

CONCLUSION

Dental treatment under GA is associated with a higher risk for DA when compared with that under PR in the long term. Increased DA may lead to uncooperative dental behaviour, although the agreement is only moderate.

[Development of a deep learning based prototype artificial intelligence system for the detection of dental caries in children]

Objective: To develop a prototype artificial intelligence image recognition system for detecting dental caries, especially those without cavities, in children. Methods: Seven hundred and twelve intraoral photos, which were taken by dental professionals using a digital camera from October 2013 to June 2020 in the Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, were collected from the children who received dental treatment under general anesthesia. The well-documented post-treatment electronic dental record of each child was identified as label standard to determine whether the teeth were carious and the type of caries types such as caries that had become cavities (caries with cavities), pit and fissure caries that had not become cavities (pit and fissure caries) and proximal caries which the marginal ridge enamel had not been destroyed (proximal caries). The various teeth and caries types were labeled by pediatric dentists using VoTT software (Windows 2.1.0, Microsoft, U S A). There were five labeled groups: pit and fissure caries, approximal caries, non-carious approximal surfaces, caries with cavities and teeth without caries (including intact fillings). Each group was randomly divided into training dataset, validation dataset and test dataset at a ratio of 6.4∶1.6∶2.0 by using random number table. After using the labeled training dataset for deep learning training, a deep learning-based artificial intelligence (AI) image recognition system for detecting dental caries was established, with the caries probability greater than 50.0% as the criterion for determining caries. Sensitivity and accuracy were used as indicators of recognition specificity. Results: Seven hundred and twelve single-jaw intraoral photographs were segmented and annotated into 953 pit and fissure caries, 1 002 approximal caries, 3 008 caries with cavities, 3 189 teeth without caries and 862 non-carious approximal surfaces, totaly 9 014 labels. The sensitivities and specificities of the test set were 96.0% and 97.0% for caries with cavities, 95.8% and 99.0% for pit and fissure caries and 88.1% and 97.1% for approximal caries. Conclusions: The current AI system developed based on deep learning of the intra-oral photos in the present study showed the ability to detect dental caries. Furthermore, the AI system could accurately verify different types of dental caries such as caries with cavities, pit and fissure caries and proximal caries.

[Occlusal contact of primary dentition at intercuspal position in children with individual normal occlusion]

Objective: To record occlusal contact of primary dentition at maximal intercuspal position in children with individual normal occlusion. Methods: A total of 57 children were recruited from patients of the Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology. Inclusion criteria were that the subjects were 3-5 years old with no visually detectable caries or pupal and periapical diseases, had complete primary dentition, had individual normal occlusion, had normal function of craniofacial system, were medically healthy, could cooperate with sampling and had obtained written informed consent from the parents or guardians. Finally, forty-seven children aged 3 to 5 years old were enrolled, including 24 males and 23 females. The age, height and weight of all subjects were (4.1±0.7) years old (ranging 3.0-5.8 years old), (103.7±7.2) cm (ranging 90-120 cm) and (17.1±2.5) kg (ranging 12.5-22.5 kg), respectively. Occlusal abilities such as occlusal contact area, average bite pressure, maximum bite pressure, maximum bite force and occlusal balance were measured with Dental Prescale Ⅱ system. Results: Maximum bite force and occlusal contact area at intercuspal position in children with primary dentition were (567.40±223.84) N (ranging 226.7-1 154.6 N) and (18.56±6.54) mm² (ranging 8.4-41.2 mm²), respectively. There was a significantly strong correlation between maximum bite force and occlusal contact area (r=0.954, P<0.01). Height and weight of children were also positively correlated with their maximum bite force (r=0.397, P=0.022 and r=0.453, P=0.008, respectively). Maximum occlusal bite force and contact occlusal area of boys [(651.80±224.34) N and (20.77±6.97) mm²] were significantly higher and larger than those of girls [(479.34±190.45) N and (16.25±5.27) mm²] (P<0.05). Thirty-two of all 47 children had one occlusal contact point with maximum bite pressure, mostly locating within the primary molar region. Bite forces of anterior and posterior teeth of primary dentition were (124.12±56.99) N and (450.11±205.09) N, respectively, about (21.82±11.40)% and (71.80±21.35)% of maximum bite force of the whole primary dentition. All of the occlusal balance points located in posterior teeth regions. Occlusal contacts were observed at both anterior and posterior teeth of primary dentition with individual normal occlusion. Conclusions: There was a great variation of maximum bite forces of primary dentitions at intercuspal position of children with individual normal occlusion. Maximum bite force of primary dentition was significantly correlated with occlusal contact area, height and weight of children. Occlusal contact points with maximum bite pressure and occlusal bite balance points of primary dentitions mostly located in primary molar regions.

Research on the correlation between activating transcription factor 3 expression in the human coronary artery and atherosclerotic plaque stability

Background

Activating transcription factor 3 (ATF3) is an early response gene that is activated in response to atherosclerotic stimulation and may be an important factor in inhibiting the progression of atherosclerosis. In this study, we directly measured the expression of ATF3 and inflammatory factors in human coronary atherosclerotic plaques to examine the relationship between ATF3 expression, inflammation and structural stability in human coronary atherosclerotic plaques.

Methods

A total of 68 coronary artery specimens were collected from the autopsy group, including 36 cases of sudden death from coronary heart disease (SCD group) and 32 cases of acute death caused by mechanical injury with coronary atherosclerosis (CHD group). Twenty-two patients who had no coronary heart disease were collected as the control group (Con group). The histological structure of the coronary artery was observed under a light microscope after routine HE staining, and the intimal and lesion thicknesses, thickness of the fibrous cap, thickness of necrosis core, degree of lumen stenosis were assessed by image analysis software. Western blotting and immunohistochemistry were used to measure the expression and distribution of ATF3, inflammatory factors (CD45, IL-1β, TNF-α) and matrix metalloproteinase-9 (MMP-9) and vascular cell adhesion molecule 1 (VCAM1) in the coronary artery. The Pearson correlation coefficient was used to analyse the correlation between ATF3 protein expression and inflammatory factors and between ATF3 protein expression and structure-related indexes in the lesion group.

Results

Compared with those in the control group, the intima and necrotic core in the coronary artery were thickened, the fibrous cap became thin and the degree of vascular stenosis was increased in the lesion group, while the intima and necrotic core became thicker and the fibrous cap became thinner in the SCD group than in the CHD group (P < 0.05). There was no or low expression of ATF3, inflammatory factors, VCAM1 and MMP-9 in the control group, and the expression of inflammatory factors, VCAM1 and MMP-9 in the SCD group was higher than that in CHD group, while the expression of ATF3 in the SCD group was significantly lower than that in CHD group (P < 0.05). In the lesion group, the expression of ATF3 was negatively correlated with intimal and necrotic focus thickness, positively correlated with fibrous cap thickness (P < 0.01), and negatively correlated with inflammatory factors, VCAM1 and MMP-9 (P < 0.01).

Conclusions

The expression of ATF3 may be related to the progression and stability of atherosclerotic plaques, and may affect the structural stability of atherosclerotic plaques by regulating the inflammatory response, thus participating in the regulation of atherosclerotic progression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02161-9.

[Expression profile of intervertebral disc degeneration-specific genes: a transcriptome sequencing-based analysis]

OBJECTIVE

To identify new therapeutic targets for intervertebral disc degeneration (IDD) by analyzing gene variations in IDD.

OBJECTIVE

We analyzed surgical samples of intervertebral disc from 4 patients with IDD and 3 patients with non-IDD using RNA sequencing (RNA-seq) technology to identify significant differentially expressed genes (DEGs) in IDD. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases were utilized for gene enrichment studies to acquire the key genes and signal pathways during IDD progression. The differential expressions of the identified genes in IDD were validated in clinical samples with qRT-PCR.

OBJECTIVE

The transcriptome profile revealed 512 significant DEGs, which were enriched in terms of keratinization, extracellular matrix (ECM) components, growth factor binding, and inflammatory chemotaxis in GO analysis. The top 10 terms of KEGG enrichment included amoebiasis, viral protein interaction with cytokine and cytokine receptor, ECM-receptor interaction, IL-17 signaling pathway, cytokine-cytokine receptor interaction, TNF signaling pathway, AGE-RAGE signaling pathway in diabetic complications, PI3K-Akt signaling pathway, chemokine signaling pathway and estrogen signaling pathway. Thirteen DEGs selected as the targets for qRT-PCR validation showed significant differential expressions in IDD (P < 0.001), and their expression trends were all consistent with the results of RNA-seq. Among these genes, 10 genes showed significant intergroup fold change (Log2FoldChange>1).

OBJECTIVE

ECM, growth factors, collagen components, inflammatory chemokines and such signal pathways as TNF-α and PI3K-Akt all have important contributions to IDD progression and may thus serve as new therapeutic targets for treatment of IDD.

Associations between Biomarkers of Exposure and Lung Cancer Risk among Exclusive Cigarette Smokers in the Golestan Cohort Study

Biomarkers of tobacco exposure are known to be associated with disease risk but previous studies are limited in number and restricted to certain regions. We conducted a nested case-control study examining baseline levels and subsequent lung cancer incidence among current male exclusive cigarette smokers in the Golestan Cohort Study in Iran. We calculated geometric mean biomarker concentrations for 28 matched cases and 52 controls for the correlation of biomarker levels among controls and for adjusted odds' ratios (ORs) for lung cancer incidence by biomarker concentration, accounting for demographic characteristics, smoking quantity and duration, and opium use. Lung cancer cases had higher average levels of most biomarkers including total nicotine equivalents (TNE-2), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), and 3-hydroxyfluorene (3-FLU). Many biomarkers correlated highly with one another including TNE-2 with NNAL and N-Acetyl-S-(2-cyanoethyl)-L-cysteine (2CYEMA), and N-Acetyl-S-(4-hydroxy-2-buten-1-yl)-L-cysteine (t4HBEMA) with N-Acetyl-S-(3-hydroxypropyl-1-methyl)-L-cysteine (3HMPMA) and N-Acetyl-S-(4-hydroxy-2-methyl-2-buten-1-yl)-L-cysteine (4HMBEMA). Lung cancer risk increased with concentration for several biomarkers, including TNE-2 (OR = 2.22, 95% CI = 1.03, 4.78) and NNN (OR = 2.44, 95% CI = 1.13, 5.27), and estimates were significant after further adjustment for demographic and smoking characteristics for 2CYEMA (OR = 2.17, 95% CI = 1.03, 4.55), N-Acetyl-S-(2-carbamoylethyl)-L-cysteine (2CAEMA) (OR = 2.14, 95% CI = 1.01, 4.55), and N-Acetyl-S-(2-hydroxypropyl)-L-cysteine (2HPMA) (OR = 2.85, 95% CI = 1.04, 7.81). Estimates were not significant with adjustment for opium use. Concentrations of many biomarkers were higher at the baseline for participants who subsequently developed lung cancer than among the matched controls. Odds of lung cancer were higher for several biomarkers including with adjustment for smoking exposure for some but not with adjustment for opium use.

Sensitive Quantification of Nicotine in Bronchoalveolar Lavage Fluid by Acetone Precipitation Combined With Isotope-Dilution Liquid Chromatography-Tandem Mass Spectrometry

The United States experienced an outbreak of e-cigarette, or vaping, product use-associated lung injury (EVALI) that began in August 2019. Patient diagnosis and treatment sometimes involved bronchoscopy and collection of the bronchoalveolar lavage (BAL) fluid. Although this matrix has been useful for understanding some chemical exposures in the lungs, no methods existed for measuring the nicotine content. Therefore, we developed a simple and sensitive method for measuring nicotine in the BAL fluid. Nicotine was extracted from the BAL fluid using acetone precipitation in a 96-well plate format to increase the sample throughput (200 samples/day). We optimized liquid chromatography column conditions (e.g., mobile phase, column temperature) and mass spectrometry parameters to improve the signal-to-noise ratio and lower limits of detection (LOD) for measuring nicotine in the BAL fluid. The LOD for nicotine in the BAL fluid was 0.050 ng/mL at a sample volume of 40 μL of the BAL fluid. The within-day and between-day imprecision and bias were less than 10%. This method detected nicotine in 15 of 43 BAL fluids from EVALI case patients. This method is useful for understanding recent inhalational exposure to nicotine as part of characterizing EVALI or similar illnesses.

Concentrations of Cotinine and 4-(Methylnitrosamino)-1-(3-Pyridyl)-1-Butanol (NNAL) in U.S. Non-Daily Cigarette Smokers

BACKGROUND

Accumulating evidence suggests that non-daily smokers have higher disease and mortality risks than never smokers. Yet, the accuracy of self-reported non-daily cigarette smoking is poorly understood.

METHODS

We examined the concordance between self-reported non-daily smoking and serum cotinine in 18,835 adult participants (20 years or older) of the 2007 to 2014 National Health and Nutrition Examination Surveys, in comparison with daily smokers and nonsmokers. We also analyzed concentrations of the urinary biomarker 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) by smoking status.

RESULTS

In the study sample, 77.8% (14,660) reported currently not smoking (nonsmokers), 18.3% (3,446) smoked every day (daily smokers), and 3.9% (729) smoked on some days of the past month (non-daily smokers). Just 2.1% of nonsmokers had cotinine concentrations in the active smoking range (>10 ng/mL), compared with 70.4% of non-daily and 98.8% of daily smokers. Non-daily smokers reported smoking a median of 24 cigarettes per month [interquartile range (IQR) = 9-60] and had substantially higher concentrations of NNAL (median = 72.5; IQR = 14.8-211.0 pg/mL) than nonsmokers (median = 0.4; IQR = 0.4-2.1 pg/mL), although lower than daily smokers (median = 294.0; IQR = 148.0-542.0 pg/mL). Among non-daily smokers, concentrations of cotinine and NNAL were positively correlated with days and cigarettes smoked per month (P < 0.001).

CONCLUSIONS

We observed excellent concordance between self-reported non-daily cigarette smoking and concentrations of serum cotinine.

IMPACT

These results provide evidence for the validity of self-reported non-daily smoking and indicate that non-daily smokers are exposed to substantial concentrations of carcinogenic nitrosamines regardless of the low number of cigarettes they smoke per month.

Tobacco-Specific Nitrosamines (NNAL, NNN, NAT, and NAB) Exposures in the US Population Assessment of Tobacco and Health (PATH) Study Wave 1 (2013-2014)

INTRODUCTION

The tobacco-specific nitrosamines (TSNAs) are an important group of carcinogens found in tobacco and tobacco smoke. To describe and characterize the levels of TSNAs in the Population Assessment of Tobacco and Health (PATH) Study Wave 1 (2013-2014), we present four biomarkers of TSNA exposure: N'-nitrosonornicotine, N'-nitrosoanabasine, N'-nitrosoanatabine, and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) which is the primary urinary metabolite of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone.

METHODS

We measured total TSNAs in 11 522 adults who provided urine using automated solid-phase extraction coupled to isotope dilution liquid chromatography-tandem mass spectrometry. After exclusions in this current analysis, we selected 11 004 NNAL results, 10 753 N'-nitrosonornicotine results, 10 919 N'-nitrosoanatabine results, and 10 996 N'-nitrosoanabasine results for data analysis. Geometric means and correlations were calculated using SAS and SUDAAN.

RESULTS

TSNA concentrations were associated with choice of tobacco product and frequency of use. Among established, every day, exclusive tobacco product users, the geometric mean urinary NNAL concentration was highest for smokeless tobacco users (993.3; 95% confidence interval [CI: 839.2, 1147.3] ng/g creatinine), followed by all types of combustible tobacco product users (285.4; 95% CI: [267.9, 303.0] ng/g creatinine), poly tobacco users (278.6; 95% CI: [254.9, 302.2] ng/g creatinine), and e-cigarette product users (6.3; 95% CI: [4.7, 7.9] ng/g creatinine). TSNA concentrations were higher in every day users than in intermittent users for all the tobacco product groups. Among single product users, exposure to TSNAs differed by sex, age, race/ethnicity, and education. Urinary TSNAs and nicotine metabolite biomarkers were also highly correlated.

CONCLUSIONS

We have provided PATH Study estimates of TSNA exposure among US adult users of a variety of tobacco products. These data can inform future tobacco product and human exposure evaluations and related regulatory activities.

[Alveolar capillary dysplasia with misalignment of the pulmonary veins: a case report and literature review]

Objective: To investigate the clinical, pathological and genetic characteristics of neonatal alveolar capillary dysplasia with misalignment of the pulmonary veins (ACDMPV). Methods: The clinical manifestations, radiographic examinations, pathology and parental genetic analysis of a newborn with FOXF1 variation induced ACDMPV, who was hospitalized in the Department of Neonatology of Shenzhen Children's Hospital in January 2020, were extracted and analyzed. Related literature up to March 2020 with the key words of "Alveolar capillaries dysplasia" "Alveolar capillary dysplasia with misalignment of the pulmonary veins" "FOXF1" in PubMed, CNKI, Wanfang, CQVIP database and Leiden Open Variation database (LOVD) were searched. Results: A full-term male newborn （1 hour of age） was admitted due to anal atresia. Surgical repair of anal atresia and omphalocele was performed on the first day of life, and gallbladder absence and Meckel's diverticulum were identified during the operation. Respiratory distress with hypoxemia developed at about 6 hours of life, and persistent pulmonary hypertension developed and progressed after surgery, with poor response to mechanical ventilation and pulmonary vasodilators. This infant passed away at 26 days of life. Lung biopsy showed decreased alveolar units and thickened interalveolar septa, reduced alveolar capillary density and thickened walls of peripheral pulmonary arteries, and misaligned pulmonary veins adjacent to the pulmonary arterioles, which were consistent with ACDMPV. The whole exome sequencing revealed a heterozygous novel frameshift of FOXF1 gene located in chromosome 16q24.1 c376_377insT; p.(Pro126fs). According to the bioinformatics analysis, this variation was likely to be pathogenic as it was associated with coding disorder of FOXF1 Pro126, resulting in truncation of the encoded protein. This novel variation had not been reported in the human gene mutation database (HGMD), ESP6500siv2_ALL, 1000g2015aug_ALL or dbSNP147 database. Previous 6 literatures reported 54 variants, including 28 missense, 10 nonsense, 11 frameshift, 2 deletion, 1 synonymous, and 2 extensions. Only three of the reported 45 cases （24 males, 21 females） were still alive as of the time of this study. Conclusions: Typically, ACDMPV is a catastrophic disease in neonatal period with high mortality. Lung biopsy and genetic testing should be considered in infants who present with persistent pulmonary hypertension and refractory hypoxemia, especially when combined with extrapulmonary abnormalities.

Differences in Exposure to Nicotine, Tobacco-Specific Nitrosamines, and Volatile Organic Compounds among Electronic Cigarette Users, Tobacco Smokers, and Dual Users from Three Countries

Country-level differences in nicotine vaping products used and biomarkers of exposure among long-term e-cigarette users and dual users remain understudied. This cross-sectional study was conducted in 2014 in the United States (n = 166), United Kingdom (n = 129), and Poland (n = 161). We compared patterns of tobacco product use and nicotine and toxicant exposure among cigarette-only smokers (n = 127); e-cigarette-only users (n = 124); dual users of tobacco cigarettes and e-cigarettes (n = 95); and non-users (control group, n = 110) across three countries using mixed-effects linear regression. Compared with cigarette smokers, e-cigarette-only users had lower levels of toxicant biomarkers, but higher levels of nicotine biomarkers. Dual users had higher levels of toxicant biomarkers than e-cigarette-only users but similar levels to cigarette-only smokers. E-cigarette users in Poland, who overwhelmingly used refillable tank devices, exhibited greater levels of nicotine, and toxicant biomarkers relative to e-cigarette users in US/UK. Despite smoking fewer cigarettes, dual users from Poland exhibited similar levels of nicotine biomarkers compared with UK dual users, but higher than US dual users. Country-level differences in e-cigarette devices used and smoking behaviors (e.g., intensity) may contribute to differences in biomarker levels among users of the same products residing in different countries.

Biomarkers of Exposure among USA Adult Hookah Users: Results from Wave 1 of the Population Assessment of Tobacco and Health (PATH) Study (2013-2014)

Hookah smoking has become common in the USA, especially among young adults. This study measured biomarkers of exposure to known tobacco product toxicants in a population-based sample of exclusive, established hookah users. Urinary biomarker data from 1753 adults in Wave 1 of the Population Assessment of Tobacco and Health (PATH) Study were used to compare geometric mean concentrations of biomarkers of exposure in exclusive, established past 30-day hookah users to never users of tobacco. Geometric mean ratios were calculated comparing hookah user groups with never users adjusting for age, sex, race/ethnicity, education, past 30-day marijuana use, secondhand smoke exposure and creatinine. Past 30-day hookah users (n = 98) had 10.6 times the urinary cotinine level of never tobacco users. Compared to never tobacco users, past 30-day hookah users had 2.3 times the level of the carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), a metabolite of the tobacco-specific nitrosamine (TSNA) 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), 1.3 times higher polycyclic aromatic hydrocarbons (PAHs) 3-hydroxyfluorene and 1-hydroxypyrene, 1.8 times higher levels of acrylonitrile, 1.3 times higher levels of acrylamide, and 1.2 times higher levels of acrolein exposure. These data indicate that hookah use is a significant source of exposure to nicotine, carcinogens, and respiratory toxicants.

Small RNA sequencing reveals miRNAs important for hypoxic adaptation in the Tibetan chicken

1. The Tibetan chicken, which is an indigenous breed living on the Tibetan Plateau, exhibits hypoxic adaptations to its high-altitude environment. However, the molecular mechanism behind this hypoxic adaptation is still unclear. This study aimed to investigate differentially expressed miRNAs involved in hypoxic adaptation through high-throughput RNA sequencing. 2. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to verify the differentially expressed miRNAs and their target genes in chicken embryonic heart tissues and fibroblasts. Luciferase reporter assays were performed to confirm the relationship between miRNAs and target genes. 3. The study identified 37 differentially expressed miRNAs in Tibetan chicken embryonic heart tissues, including 20 up- and 17 down-regulated miRNAs, compared to those found in lowland chickens. Differentially expressed miRNAs were mainly involved in biological processes, such as cell cycle arrest, toll-like receptor signalling pathways, and I-kappa B kinase/NF-kappa B signalling. The data showed that gga-miR-34 c-5p was significantly upregulated in Tibetan chicken tissues and hypoxic fibroblasts, while EHHADH, a target gene of gga-miR-34 c-5p, was downregulated. Moreover, gga-miR-34 c-5p dramatically decreased the luciferase activity of the wild EHHADH, whereas no effect on the mutational EHHADH was found. 4. This study identified miRNA expression profiles in the Tibetan chicken and suggested that miR-34 c-5p acts as a novel miRNA associated with hypoxic adaptation. This facilitates the understanding of molecular mechanisms that underlie long-term exposure to hypoxia.

Application of Sequential Changes of Dural Thickness and Biomechanical Parameters in Postmortem Interval Estimation

Abstract

Objective To study the relations of the dural thickness and the biomechanical parameters with postmortem interval （PMI） of human cadavers, and to explore the feasibility of the two indexes used for PMI estimation. Methods Dural samples were collected at different postmortem intervals of 6 h, 12 h, 18 h, 24 h, 30 h, 36 h, 48 h, 60 h, 72 h, 84 h and 96 h, then fabricated into 4.0 cm×1.0 cm A and B test specimens. The thickness of the A test specimen was measured, and the biomechanical parameters, such as ultimate load, maximum force deformation, tensile strength, elastic modulus and fracture force, were measured. The regression equations of thickness, biomechanical parameters and PMI were fitted respectively, and the difference between the predicted value and actual measured value of PMI was verified by the verification group. The B test specimen was fixed with 10% neutral formaldehyde solution, then tissue sections were prepared to observe its morphological changes. Results From 6 h to 96 h after death, the dural thickness decreased gradually, the collagen fibers gradually changed from clear arrangement to mutual fusion, and the number of nuclei decreased gradually. The dural thickness, ultimate load, tensile strength, elastic modulus and fracture force decreased sequentially, among which the dural thickness, ultimate load, elastic modulus and fracture force had a correlation with PMI （P<0.05）. In the return test, the difference between the predicted value and actual measured value of PMI in the verification group had no statistical significance （P>0.05）. Conclusion The dural thickness, ultimate load, elastic modulus and fracture force change sequentially from 6 h to 96 h after death. The regression equation established by the relationship between the changes and PMI can be used for PMI estimation.

High-Throughput and Sensitive Analysis of Free and Total 8-Isoprostane in Urine with Isotope-Dilution Liquid Chromatography-Tandem Mass Spectrometry

Oxidative stress (OS) plays a major role in the pathogenesis of various diseases in humans. OS is a result of an imbalance between reactive oxygen species (ROS) and the biologically available antioxidants that prevent or repair damage that ROS inflict on the host cells. ROS are naturally generated during normal mitochondrial respiration and by oxidative burst during the immune response. Many factors may influence OS, including genetics, diet, exercise, and exposure to environmental toxicants (e.g., tobacco smoke). A nonenzymatic peroxidation product of arachidonic acid (AA), 8-iso-PGF_2α (8-isoprostane), is a validated biomarker of OS that is present in urine as both glucuronide conjugate and free acid. Previous studies report that the conjugated forms of 8-isoprostane can vary between 30 and 80% of the total 8-isoprostane levels. By hydrolyzing the conjugated forms, it is possible to obtain a total (free + conjugated) measurement of 8-isoprostane in urine samples. Here, we describe a robust, automated, and high-throughput method for measuring total urinary 8-isoprostane using a polymeric weak anion-exchange solid-phase extraction (SPE) and isotope-dilution ultrahigh performance liquid chromatography electrospray ionization-tandem mass spectrometry (UHPLC-MS/MS). This method, using a 96-well plate platform, showed good sensitivity (8.8 pg/mL LOD) and used only 400 μL of the sample volume with a cycle time of 11 min. The inter- and intraday precision, calculated from 20 repeated measurements of two quality control pools, varied from 4 to 10%. Accuracy, calculated from the recovery percentage at three spiking levels, ranged from 92.7 to 106.7%. We modified this method to allow for the exclusive measurement of free 8-isoprostane by removing the hydrolysis step. We measured both free and total 8-isoprostane in urine collected from 30 cigarette smokers (free: 460 ± 78.8 pg/mL; total: 704 ± 108 pg/mL) and 30 nonusers of tobacco products (free: 110 ± 24.2 pg/mL; total: 161 ± 38.7 pg/mL). This method is robust, accurate, and easily adaptable for large population studies.

Biomarkers of Exposure among Adult Smokeless Tobacco Users in the Population Assessment of Tobacco and Health Study (Wave 1, 2013-2014)

BACKGROUND

Monitoring population-level toxicant exposures from smokeless tobacco (SLT) use is important for assessing population health risks due to product use. In this study, we assessed tobacco biomarkers of exposure (BOE) among SLT users from the Wave 1 (2013-2014) of the Population Assessment of Tobacco and Health (PATH) Study.

METHODS

Urinary biospecimens were collected from adults ages 18 and older. Biomarkers of nicotine, tobacco-specific nitrosamines (TSNA), polycyclic aromatic hydrocarbons (PAH), volatile organic compounds (VOC), metals, and inorganic arsenic were analyzed and reported among exclusive current established SLT users in comparison with exclusive current established cigarette smokers, dual SLT and cigarette users, and never tobacco users.

RESULTS

In general, SLT users (n = 448) have significantly higher concentrations of BOE to nicotine, TSNAs, and PAHs compared with never tobacco users; significant dose-response relationships between frequency of SLT use and biomarker concentrations were also reported among exclusive SLT daily users. Exclusive SLT daily users have higher geometric mean concentrations of total nicotine equivalent-2 (TNE2) and TSNAs than exclusive cigarette daily smokers. In contrast, geometric mean concentrations of PAHs and VOCs were substantially lower among exclusive SLT daily users than exclusive cigarette daily smokers.

CONCLUSIONS

Our study produced a comprehensive assessment of SLT product use and 52 biomarkers of tobacco exposure. Compared with cigarette smokers, SLT users experience greater concentrations of some tobacco toxicants, including nicotine and TSNAs.

IMPACT

Our data add information on the risk assessment of exposure to SLT-related toxicants. High levels of harmful constituents in SLT remain a health concern.

Opiate and Tobacco Use and Exposure to Carcinogens and Toxicants in the Golestan Cohort Study

BACKGROUND

There is little information on human exposure to carcinogens and other toxicants related to opiate use, alone or in combination with tobacco.

METHODS

Among male participants of the Golestan Cohort Study in Northeast Iran, we studied 28 never users of either opiates or tobacco, 33 exclusive cigarette smokers, 23 exclusive users of smoked opiates, and 30 opiate users who also smoked cigarettes (dual users; 21 smoked opiates and 9 ingested them). We quantified urinary concentrations of 39 exposure biomarkers, including tobacco alkaloids, tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons (PAH), and volatile organic compounds (VOC), and used decomposition to parse out the share of the biomarker concentrations explained by opiate use and nicotine dose.

RESULTS

Dual users had the highest concentrations of all biomarkers, but exclusive cigarette smokers and exclusive opiate users had substantially higher concentrations of PAH and VOC biomarkers than never users of either product. Decomposition analysis showed that opiate use contributed a larger part of the PAH concentrations than nicotine dose, and the sum of 2- and 3-hydroxyphenanthrene (∑2,3-phe) resulted almost completely from opiate use. Concentrations of most VOC biomarkers were explained by both nicotine dose and opiate use. Two acrylamide metabolites, a 1,3-butadiene metabolite and a dimethylformamide metabolite, were more strongly explained by opiate use. Acrylamide metabolites and ∑2,3-phe were significantly higher in opiate smokers than opiate eaters; other biomarkers did not vary by the route of opiate intake.

CONCLUSIONS

Both cigarette smokers and opiate users (by smoking or ingestion) were exposed to many toxicants and carcinogens.

IMPACT

This high exposure, particularly among dual opiate and cigarette users, can have a substantial global public health impact.

Vitamin E Acetate in Bronchoalveolar-Lavage Fluid Associated with EVALI

BACKGROUND

The causative agents for the current national outbreak of electronic-cigarette, or vaping, product use-associated lung injury (EVALI) have not been established. Detection of toxicants in bronchoalveolar-lavage (BAL) fluid from patients with EVALI can provide direct information on exposure within the lung.

METHODS

BAL fluids were collected from 51 patients with EVALI in 16 states and from 99 healthy participants who were part of an ongoing study of smoking involving nonsmokers, exclusive users of e-cigarettes or vaping products, and exclusive cigarette smokers that was initiated in 2015. Using the BAL fluid, we performed isotope dilution mass spectrometry to measure several priority toxicants: vitamin E acetate, plant oils, medium-chain triglyceride oil, coconut oil, petroleum distillates, and diluent terpenes.

RESULTS

State and local health departments assigned EVALI case status as confirmed for 25 patients and as probable for 26 patients. Vitamin E acetate was identified in BAL fluid obtained from 48 of 51 case patients (94%) in 16 states but not in such fluid obtained from the healthy comparator group. No other priority toxicants were found in BAL fluid from the case patients or the comparator group, except for coconut oil and limonene, which were found in 1 patient each. Among the case patients for whom laboratory or epidemiologic data were available, 47 of 50 (94%) had detectable tetrahydrocannabinol (THC) or its metabolites in BAL fluid or had reported vaping THC products in the 90 days before the onset of illness. Nicotine or its metabolites were detected in 30 of 47 of the case patients (64%).

CONCLUSIONS

Vitamin E acetate was associated with EVALI in a convenience sample of 51 patients in 16 states across the United States. (Funded by the National Cancer Institute and others.).

Evaluation of Tobacco Smoke and Diet as Sources of Exposure to Two Heterocyclic Aromatic Amines for the U.S. Population: NHANES 2013-2014

BACKGROUND

Heterocyclic aromatic amines (HAA) are a group of hazardous substances produced during combustion of tobacco or high-temperature cooking of meats. 2-Amino-9H-pyrido[2,3-b]indole (AαC) is a major carcinogenic HAA in tobacco smoke.

METHODS

Urinary AαC, used as a marker of AαC exposure, was analyzed on spot urine samples from adult participants of the 2013-2014 cycle of the National Health and Nutrition Examination Survey (N = 1,792). AαC was measured using isotope-dilution liquid chromatography-tandem mass spectrometry. Exclusive combusted tobacco smokers were differentiated from nonusers of tobacco products through both self-report and serum cotinine data.

RESULTS

Among exclusive smokers, sample-weighted median urinary AαC was 40 times higher than nonusers. Sample-weighted regression models showed that urinary AαC increased significantly with serum cotinine among both exclusive tobacco users and nonusers with secondhand smoke exposure. Among nonusers, eating beef cooked at high temperature was associated with a significant increase in urinary AαC, whereas consuming vegetables was associated with decreased AαC. In addition, smoking one-half pack of cigarettes per day was associated with a significant increase of 23.6 pg AαC/mL calculated at geometric mean of AαC, controlling for potential confounders. In comparison, increase in AαC attributable to consuming the 99th percentile of beef cooked at high temperature was 0.99 pg AαC/mL.

CONCLUSIONS

Both exclusive smokers and nonusers of tobacco in the general U.S. population are exposed to AαC from tobacco smoke, with additional, lesser contributions from certain dietary components.

IMPACT

AαC is an important biomarker that is associated with tobacco smoke exposure.

Evaluation of Bronchoalveolar Lavage Fluid from Patients in an Outbreak of E-cigarette, or Vaping, Product Use-Associated Lung Injury - 10 States, August-October 2019

CDC, the Food and Drug Administration (FDA), state and local health departments, and multiple public health and clinical partners are investigating a national outbreak of e-cigarette, or vaping, product use-associated lung injury (EVALI). Based on data collected as of October 15, 2019, 86% of 867 EVALI patients reported using tetrahydrocannabinol (THC)-containing products in the 3 months preceding symptom onset (1). Analyses of THC-containing product samples by FDA and state public health laboratories have identified potentially harmful constituents in these products, such as vitamin E acetate, medium chain triglyceride oil (MCT oil), and other lipids (2,3) (personal communication, D.T. Heitkemper, FDA Forensic Chemistry Center, November 2019). Vitamin E acetate, in particular, might be used as an additive in the production of e-cigarette, or vaping, products; it also can be used as a thickening agent in THC products (4). Inhalation of vitamin E acetate might impair lung function (5-7).