Switching from onabotulinum toxin A to abobotulinum toxin A for treating detrusor overactivity in spinal cord injured patient, does it really work?

AIM

To assess the efficacy of switching to Abobotulinumtoxin A (ATA) intradetrusor injections (IDI) after failure of Onabotulinumtoxin A (OTA) IDI for the treatment of neurogenic detrusor overactivity in patients with spinal cord injury (SCI).

MATERIALS AND METHODS

A single-centre retrospective chart review study. All SCI patients who started OTA IDI after 2011 and had an ATA IDI switch were included. The primary outcome was the clinical and urodynamic efficacy of the switch to ATA IIDs at the last follow-up. Secondary outcomes were initial efficacy, duration of ATA treatment, and patient outcome including the occurrence of augmentation enterocystoplasty at last follow-up.

RESULTS

Sixty-two patients were included. Eighteen patients (28.9%) were initially responders to ATA IDI. Nine patients (14.5%) remained responders at last follow-up after a median of 17 months (AE 8.8-29). Thirty-two patients (51.6%) had had or were awaiting augmentation enterocystoplasty with a follow-up time of 18.5 months (IQR 8-27). Eleven patients (17.7%) were on ATA IDI with low efficacy. Seven patients (11.3%) were switched back to OTA and 3 patients (4.8%) changed their voiding pattern.

CONCLUSION

Switching from OTA to ATA toxin for IDI in the treatment of detrusor overactivity after spinal cord injury have long-term efficacy for a limited number of patients but may delay the need for surgery.

LEVEL OF EVIDENCE: 4

A prospective, multi-center, practice-based cohort study on all-ceramic crowns

OBJECTIVES

The aim of this prospective, multi-center, practice-based cohort study was to analyze factors associated with the success of all-ceramic crowns.

METHODS

All-ceramic crowns placed in a practice-based research network ([Ceramic Success Analysis, AG Keramik) were analyzed. Data from 1254 patients with (mostly in-office CAD/CAM) all-ceramic crowns placed by 101 dentists being followed up for more than 5 years were evaluated. At the last follow-up visit crowns were considered as successful (not failed) if they were sufficient, whereas crowns were considered as survived (not lost) if they were still in function. Multi-level Cox proportional hazards models were used to evaluate the association between a range of predictors and time of success or survival.

RESULTS

Within a mean follow-up period (SD) of 7.2(2)years [maximum:15years] 776 crowns were considered successful (annual failure rate[AFR]:8.4%) and 1041 crowns survived (AFR:4.9%). The presence of a post in endodontically treated teeth resulted in a risk for failure 2.7 times lower than that of restorations without a post (95%CI:1.4-5.0;p = 0.002). Regarding the restorative material and adhesive technique, hybrid composite ceramics and single-step adhesives showed a 3.4 and 2.2 times higher failure rate than feldspathic porcelain and multi-step adhesives, respectively (p < 0.001). Use of an oxygen-blocking gel as well as an EVA instrument resulted in a 1.5-1.8 times higher failure rate than their non-use (p ≤ 0.001).

SIGNIFICANCE

After up to 15years AFR were rather high for all-ceramic crowns. Operative factors, but no patient- or tooth-level factors were significantly associated with failure. The study was registered in the German Clinical Trials Register (DRKS-ID: DRKS00020271).

Spinal cord injury: A multisystem physiological impairment/dysfunction

Spinal cord injury (SCI) is a complex disease that affects not only sensory and motor pathways below the neurological level of injury (NLI) but also all the organs and systems situated below this NLI. This multisystem impairment implies comprehensive management in dedicated SCI specialized centers, by interdisciplinary and multidisciplinary teams, able to treat not only the neurological impairment, but also all the systems and organs affected. After a brief history of the Spinal Cord Medicine, the author describes how to determine the level and severity of a SCI based on the International Standards for Neurological Classification of Spinal Cord Injury and the prognosis factors of recovery. This article provides also a review of the numerous SCI-related impairments (except for urinary, sexual problems and pain treated separately in this issue), their principles of management and related complications.

[External sphincterotomy in neurological patients with detrusor sphincter dyssynergia: Short and mid-term results]

BACKGROUND

To evaluate in the short and mid-term the success of external sphincterotomy (ES) in neurological patients with detrusor sphincter dyssynergia (DSD).

METHODS

Retrospective, monocentric study, conducted in 51 patients who had a first ES between January 2003 and June 2018, with at least two years of follow-up. The success of ES was defined by maintenance of reflex voiding mode at the end of follow-up. Secondary outcomes were early postoperative complications, rate of revision, functional impact, urodynamic follow-up and upper urinary tract impact.

RESULTS

The median age was 50.6 years and the median follow-up was 4.6 years. The success rate was 80% (n=41). Ten patients had to change their voiding mode. For 5 patients, it was related to secondary detrusor low contractility. A second ES was required for 39% of patients. At the end of follow-up, there was a significant improvement in Autonomic Dysreflexia (AD) (26 vs 7 patients, P<0.001), urinary tract infections (UTI) (31 vs 15 patients, P<0.001) and a significant decrease in post-voiding residuals (200 vs 50mL, P<0.001).

CONCLUSION

ES allowed to maintain reflex voiding in 80% of our patients. It significantly improves AD and UTI despite a high rate of re-operation (39%). A long-term follow-up is mandatory in order not to ignore a recurrence of bladder outlet obstruction and/or decrease in detrusor contractility, which may justify a re-operation or an alternative bladder management.

LEVEL OF EVIDENCE

III.

Constituents of Household Air Pollution and Risk of Lung Cancer among Never-Smoking Women in Xuanwei and Fuyuan, China

BACKGROUND

Lung cancer rates among never-smoking women in Xuanwei and Fuyuan in China are among the highest in the world and have been attributed to the domestic use of smoky (bituminous) coal for heating and cooking. However, the key components of coal that drive lung cancer risk have not been identified.

OBJECTIVES

We aimed to investigate the relationship between lifelong exposure to the constituents of smoky coal (and other fuel types) and lung cancer.

METHODS

Using a population-based case-control study of lung cancer among 1,015 never-smoking female cases and 485 controls, we examined the association between exposure to 43 household air pollutants and lung cancer. Pollutant predictions were derived from a comprehensive exposure assessment study, which included methylated polycyclic aromatic hydrocarbons (PAHs), which have never been directly evaluated in an epidemiological study of any cancer. Hierarchical clustering and penalized regression were applied in order to address high colinearity in exposure variables.

RESULTS

The strongest association with lung cancer was for a cluster of 25 PAHs [odds ratio (OR): 2.21; 95% confidence interval (CI): 1.67, 2.87 per 1 standard deviation (SD) change], within which 5-methylchrysene (5-MC), a mutagenic and carcinogenic PAH, had the highest individual observed OR (5.42; 95% CI: 0.94, 27.5). A positive association with nitrogen dioxide ([Formula: see text]) was also observed (OR: 2.06; 95% CI: 1.19, 3.49). By contrast, neither benzo(a)pyrene (BaP) nor fine particulate matter with aerodynamic diameter [Formula: see text] ([Formula: see text]) were associated with lung cancer in the multipollutant models.

CONCLUSIONS

To our knowledge, this is the first study to comprehensively evaluate the association between lung cancer and household air pollution (HAP) constituents estimated over the entire life course. Given the global ubiquity of coal use domestically for indoor cooking and heating and commercially for electric power generation, our study suggests that more extensive monitoring of coal combustion products, including methylated PAHs, may be warranted to more accurately assess health risks and develop prevention strategies from this exposure. https://doi.org/10.1289/EHP4913.

Human exposure to trichloroethylene is associated with increased variability of blood DNA methylation that is enriched in genes and pathways related to autoimmune disease and cancer

Human exposure to trichloroethylene (TCE) is linked to kidney cancer, autoimmune diseases, and probably non-Hodgkin lymphoma. Additionally, TCE exposed mice and cell cultures show altered DNA methylation. To evaluate associations between TCE exposure and DNA methylation in humans, we conducted an epigenome-wide association study (EWAS) in TCE exposed workers using the HumanMethylation450 BeadChip. Across individual CpG probes, genomic regions, and globally (i.e., the 450K methylome), we investigated differences in mean DNA methylation and differences in variability of DNA methylation between 73 control (< 0.005 ppm TCE), 30 lower exposed (< 10 ppm TCE), and 37 higher exposed ( ≥ 10 ppm TCE) subjects' white blood cells. We found that TCE exposure increased methylation variation globally (Kruskal-Wallis p-value = 3.75e-3) and in 25 CpG sites at a genome-wide significance level (Bonferroni p-value < 0.05). We identified a 609 basepair region in the TRIM68 gene promoter that exhibited hypomethylation with increased exposure to TCE (FWER = 1.20e-2). Also, genes that matched to differentially variable CpGs were enriched in the 'focal adhesion' biological pathway (p-value = 2.80e-2). All in all, human exposure to TCE was associated with epigenetic alterations in genes involved in cell-matrix adhesions and interferon subtype expression, which are important in the development of autoimmune diseases; and in genes related to cancer development. These results suggest that DNA methylation may play a role in the pathogenesis of TCE exposure-related diseases and that TCE exposure may contribute to epigenetic drift.

Abstract 5313: Occupational exposure to trichloroethylene and DNA methylation: a cross-sectional study

Trichloroethylene (TCE) is a chlorinated solvent that is often used in occupational settings for vapor degreasing of metal parts. In 2012, TCE was classified as a known human carcinogen (Group 1) by the International Agency for Research on Cancer, largely based on evidence for kidney cancer. Animal studies have suggested that TCE may modulate DNA methylation. We performed a cross-sectional study to examine the associations of DNA methylation of individual CpG sites with TCE exposure. We enrolled 80 workers from factories where TCE was used, as well as 96 unexposed controls from food and clothes manufacturing factories in the same region, and 69 exposed workers and 77 controls were available for analyses in this study. Personal exposure measurements (2-3 per subject) were collected for a full work shift using a 3MTM badge in both exposed workers and a subgroup of the control workers. Blood samples were collected from each subject and CpG methylation was assayed on the Illumina Infinium HumanMethylation450 BeadChip. After quality controls procedures, 485,512 CpG probes were available for analyses. We used separate multivariable linear regression models to examine the associations of TCE exposure and the methylation level at each single CpG site. All models were adjusted for age, sex, current smoking status, current alcohol consumption, recent infection, and body mass index. The median TCE exposure level in exposed subjects was 12 ppm (10th percentile: 2 ppm; 90th percentile: 45 ppm). We found 29 CpG probes that achieved genome-wide significance (p &lt; 1.04x10-7) when comparing TCE exposed workers with controls. TCE exposure was associated with hypomethylation at nearly all (28/29) of those CpG probes. Of these 29 CpG probes, 6 CpGs showed a significant (p &lt; 1.04x10-7) exposure-response relationship across the categories of controls and lower- (&lt;12ppm) and higher-exposed (≥12 ppm) workers, and were mapped to 6 different chromosomes. To our knowledge, this is the first report that TCE exposure is associated with alterations in DNA methylation in a molecular epidemiologic study. Our findings may provide insight into potential biological mechanisms linking exposure to TCE and adverse health outcomes.

Citation Format: Jinming Zhang, Luoping Zhang, Roel Vermeulen, Wei Hu, Bryan A. Bassig, Jason Y. Wong, Min Shen, Bu-Tian Ji, Boris Reiss, Mark Purdue, Martyn T. Smith, Qing Lan, Nathaniel Rothman. Occupational exposure to trichloroethylene and DNA methylation: a cross-sectional study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5313.

Abstract 3239: Molecular biomarkers and indoor household air pollution in a rural area of China

To explore the influence of fuel source used for home heating and cooking on biomarkers of potential genomic instability, we analyzed biological samples obtained from a cross-sectional study of 104 female never-smokers enrolled from 30 villages in Xuanwei and Fuyuan in Yunnan Province, a rural region with a high incidence of lung cancer in China. Study subjects who used primarily smoky (i.e., bituminous) coal (n=80), smokeless coal (i.e., anthracite) (n=14) and wood (n=10) were analyzed. Personal 24-h air PM2.5 and polycyclic aromatic hydrocarbon concentrations were measured over two consecutive days in each household. DNA was extracted from peripheral white blood cells. We assayed molecular biomarkers of potential genomic instability including the Alu copy number to albumin gene (ALB) ratio (Alu/ALB), 5.8S ribosomal DNA to ALB ratio (5.8S rDNA/ALB) and 18S ribosomal DNA to ALB ratio (18S rDNA/ALB), which were weakly to highly correlated with each other. Multiple linear regression was performed to analyze the association between fuel type and these biomarkers, adjusted for age, as well as the influence of benzo[a]pyrene (BaP) and PM2.5 concentration. There was a significant difference (p = 0.041) in levels of 18S rDNA/ALB among the three exposure groups [mean (standard deviation [sd]) = 1.30 (0.42), 1.58 (0.72), and 1.65 (0.62) among smoky, smokeless coal and wood users, respectively]. There were substantial differences in personal PM2.5 exposure among smoky coal, smokeless coal, and wood users [mean (sd) =184 (127), 227 (318), and 433 (284) µg/m3, respectively, p = 0.0004]. PM2.5 exposure was significantly and positively associated with 18S rDNA/ALB (p = 0.001). Further, after adjustment for PM2.5, the association between fuel type and 18S rDNA/ALB became non-significant (p = 0.24). Similar positive associations were observed between PM2.5 and 5.8S rDNA/ALB (p=0.009) and Alu/ALB (p=0.0003). There were no associations identified between BaP and these biomarkers after adjustment for PM2.5. Our findings suggest that exposure to PM2.5, which has been associated with increased risks of lung cancer and cardiovascular disease, may alter potential molecular markers of genomic instability. Additional studies are needed to confirm these findings and further understand the role of these biomarkers in predicting human health effects.

Citation Format: Wei Hu, Richard M. Cawthon, George Downward, Boris Reiss, Jihua Li, Jun He, Jun Xu, Wei Jie Seow, Bryan A. Bassig, Jason Y. Wong, Dean Hosgood, Lützen Portengen, Nathaniel Rothman, Roel Vermeulen, Qing Lan. Molecular biomarkers and indoor household air pollution in a rural area of China [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3239.

Quartz in ash, and air in a high lung cancer incidence area in China

Exposure to crystalline silica (quartz) has been implicated as a potential cause of the high lung cancer rates in the neighbouring counties of Xuanwei and Fuyuan, China, where the domestic combustion of locally sourced "smoky" coal (a bituminous coal) is responsible for some of the highest lung cancer rates in the nation, irrespective of gender or smoking status. Previous studies have shown that smoky coal contains approximately twice as much quartz when compared to alternative fuels in the area, although it is unclear how the quartz in coal relates to household air pollution. Samples of ash and fine particulate matter (PM_2.5) were collected from 163 households and analysed for quartz content by Fourier transformed infrared spectroscopy (FT-IR). Additionally, air samples from 12 further households, were analysed by scanning electron microscopy (SEM) to evaluate particle structure and silica content. The majority (89%) of household air samples had undetectable quartz levels (<0.2 μg/m³) with no clear differences by fuel-type. SEM analyses indicated that there were higher amounts of silica in the smoke of smoky coal than smokeless coal (0.27 μg/m³ vs. 0.03 μg/m³). We also identified fibre-like particles in a higher concentration within the smoke of smoky coal than smokeless coal (5800 fibres/m³ vs. 550 fibres/m³). Ash analysis suggested that the bulk of the quartz in smoky coal went on to form part of the ash. These findings indicate that the quartz within smoky coal does not become adequately airborne during the combustion process to cause significant lung cancer risk, instead going on to form part of the ash. The identification of fibre-like particles in air samples is an interesting finding, although the clinical relevance of this finding remains unclear.

High-resolution metabolomics of occupational exposure to trichloroethylene

Background: Occupational exposure to trichloroethylene (TCE) has been linked to adverse health outcomes including non-Hodgkin’s lymphoma and kidney and liver cancer; however, TCE’s mode of action for development of these diseases in humans is not well understood.

Methods: Non-targeted metabolomics analysis of plasma obtained from 80 TCE-exposed workers [full shift exposure range of 0.4 to 230 parts-per-million of air (ppm_a)] and 95 matched controls were completed by ultra-high resolution mass spectrometry. Biological response to TCE exposure was determined using a metabolome-wide association study (MWAS) framework, with metabolic changes and plasma TCE metabolites evaluated by dose-response and pathway enrichment. Biological perturbations were then linked to immunological, renal and exposure molecular markers measured in the same population.

Results: Metabolic features associated with TCE exposure included known TCE metabolites, unidentifiable chlorinated compounds and endogenous metabolites. Exposure resulted in a systemic response in endogenous metabolism, including disruption in purine catabolism and decreases in sulphur amino acid and bile acid biosynthesis pathways. Metabolite associations with TCE exposure included uric acid (β = 0.13, P-value = 3.6 × 10⁻⁵), glutamine (β = 0.08, P-value = 0.0013), cystine (β = 0.75, P-value = 0.0022), methylthioadenosine (β = −1.6, P-value = 0.0043), taurine (β = −2.4, P-value = 0.0011) and chenodeoxycholic acid (β = −1.3, P-value = 0.0039), which are consistent with known toxic effects of TCE, including immunosuppression, hepatotoxicity and nephrotoxicity. Correlation with additional exposure markers and physiological endpoints supported known disease associations.

Conclusions: High-resolution metabolomics correlates measured occupational exposure to internal dose and metabolic response, providing insight into molecular mechanisms of exposure-related disease aetiology.

Indoor concentrations of nitrogen dioxide and sulfur dioxide from burning solid fuels for cooking and heating in Yunnan Province, China

The Chinese national pollution census has indicated that the domestic burning of solid fuels is an important contributor to nitrogen dioxide (NO2 ) and sulfur dioxide (SO2 ) emissions in China. To characterize indoor NO2 and SO2 air concentrations in relation to solid fuel use and stove ventilation in the rural counties of Xuanwei and Fuyuan, in Yunnan Province, China, which have among the highest lung cancer rates in the nation, a total of 163 participants in 30 selected villages were enrolled. Indoor 24-h NO2 and SO2 samples were collected in each household over two consecutive days. Compared to smoky coal, smokeless coal use was associated with higher NO2 concentrations [geometric mean (GM) = 132 μg/m(3) for smokeless coal and 111 μg/m(3) for smoky coal, P = 0.065] and SO2 [limit of detection = 24 μg/m(3) ; percentage detected (%Detect) = 86% for smokeless coal and 40% for smoky coal, P < 0.001]. Among smoky coal users, significant variation of NO2 and SO2 air concentrations was observed across different stove designs and smoky coal sources in both counties. Model construction indicated that the measurements of both pollutants were influenced by stove design. This exposure assessment study has identified high levels of NO2 and SO2 as a result of burning solid fuels for cooking and heating.

Outdoor, indoor, and personal black carbon exposure from cookstoves burning solid fuels

Black carbon (BC) emissions from solid fuel combustion are associated with increased morbidity and mortality and are important drivers of climate change. We studied BC measurements, approximated by particulate matter (PM2.5 ) absorbance, in rural Yunnan province, China, whose residents use a variety of solid fuels for cooking and heating including bituminous and anthracite coal, and wood. Measurements were taken over two consecutive 24-h periods from 163 households in 30 villages. PM2.5 absorbance (PMabs ) was measured using an EEL 043 Smoke Stain Reflectometer. PMabs measurements were higher in wood burning households (16.3 × 10(-5) /m) than bituminous and anthracite coal households (12 and 5.1 × 10(-5) /m, respectively). Among bituminous coal users, measurements varied by a factor of two depending on the coal source. Portable stoves (which are lit outdoors and brought indoors for use) were associated with reduced PMabs levels, but no other impact of stove design was observed. Outdoor measurements were positively correlated with and approximately half the level of indoor measurements (r = 0.49, P < 0.01). Measurements of BC (as approximated by PMabs ) in this population are modulated by fuel type and source. This provides valuable insight into potential morbidity, mortality, and climate change contributions of domestic usage of solid fuels.

Abstract 3432: Outdoor air pollution and household coal combustion in a rural high lung cancer incidence area of China

Outdoor air pollution inside populated areas is a growing environmental health concern. Epidemiological data related to exposures to outdoor air pollution are limited in rural areas. We previously assessed indoor and personal exposures in two Chinese rural counties, Xuanwei and Fuyuan, where the domestic combustion of locally sourced “smoky” (i.e., bituminous) but not “smokeless” (i.e., anthracite) coal has been associated with the highest lung cancer rates in China. In addition, we have previously reported that improving home ventilation by installing stoves with chimneys was associated with a reduction in lung cancer rates in this region. However, outdoor air pollution from indoor burning of coal and the impact of improving household ventilation on outdoor air pollution have never been assessed in this area. Therefore, we measured outdoor fine particulate matter (PM2.5) and polycyclic aromatic hydrocarbons (PAHs) including the known carcinogen benzo-a-pyrene (BaP) over two consecutive 24-hour sampling periods in 29 villages. Half of the villages were revisited several months after the initial sampling period to repeat all measurements. The overall concentrations of outdoor pollutants in Xuanwei and Fuyuan were 53.1 μg/m3 (13.2-103.4 μg/m3) for PM2.5, and 11.1 ng/m3 (5.9-19.8 ng/m3) for BaP. PM2.5 levels were almost twice as high as the 24-hour mean World Health Organization guideline value of 25 μg/m3. Outdoor BaP concentrations in villages with homes using smoky coal were significantly higher than those with homes that used smokeless coal (11.6 vs 5.9 ng/m3, p &lt; 0.05). Among villages using smoky coal, higher outdoor BaP levels were found in villages where &gt;50% of households had a chimney compared to villages where ≤50% of homes had a chimney (12.3 vs 7.1 ng/m3, p = 0.024). Outdoor PM2.5 was moderately correlated with the indoor concentration (Spearman rs = 0.28, p = 0.011). These results show that outdoor air pollution in a rural region of China with a high incidence of lung cancer was associated with type of coal used for cooking and heating indoors and the presence of stove ventilation. These findings suggest that further reducing adverse health effects in rural villages from home burning of coal will likely require use of stoves that reduce environmental exhaust and/or the replacement of coal with cleaner fuel types.

Citation Format: Wei Hu, George Downward, Boris Reiss, Nathaniel Rothman, Jihua Li, Jun He, K.F Morales-Collins, Jun Xu, Weijie Seow, Bryan Bassig, Dean Hosgood, Linlin Zhang, M Hoogeveen, Ingrid Rijk, Guoping Wu, Fusheng Wei, Roel Vermeulen, Qing Lan. Outdoor air pollution and household coal combustion in a rural high lung cancer incidence area of China. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3432.

Comparison of hematological alterations and markers of B-cell activation in workers exposed to benzene, formaldehyde and trichloroethylene

Benzene, formaldehyde (FA) and trichloroethylene (TCE) are ubiquitous chemicals in workplaces and the general environment. Benzene is an established myeloid leukemogen and probable lymphomagen. FA is classified as a myeloid leukemogen but has not been associated with non-Hodgkin lymphoma (NHL), whereas TCE has been associated with NHL but not myeloid leukemia. Epidemiologic associations between FA and myeloid leukemia, and between benzene, TCE and NHL are, however, still debated. Previously, we showed that these chemicals are associated with hematotoxicity in cross-sectional studies of factory workers in China, which included extensive personal monitoring and biological sample collection. Here, we compare and contrast patterns of hematotoxicity, monosomy 7 in myeloid progenitor cells (MPCs), and B-cell activation biomarkers across these studies to further evaluate possible mechanisms of action and consistency of effects with observed hematologic cancer risks. Workers exposed to benzene or FA, but not TCE, showed declines in cell types derived from MPCs, including granulocytes and platelets. Alterations in lymphoid cell types, including B cells and CD4+ T cells, and B-cell activation markers were apparent in workers exposed to benzene or TCE. Given that alterations in myeloid and lymphoid cell types are associated with hematological malignancies, our data provide biologic insight into the epidemiological evidence linking benzene and FA exposure with myeloid leukemia risk, and TCE and benzene exposure with NHL risk.

Gene-expression profiling of buccal epithelium among non-smoking women exposed to household air pollution from smoky coal

In China's rural counties of Xuanwei and Fuyuan, lung cancer rates are among the highest in the world. While the elevated disease risk in this population has been linked to the usage of smoky (bituminous) coal as compared to smokeless (anthracite) coal, the underlying molecular changes associated with this exposure remains unclear. To understand the physiologic effects of smoky coal exposure, we analyzed the genome-wide gene-expression profiles in buccal epithelial cells collected from healthy, non-smoking female residents of Xuanwei and Fuyuan who burn smoky (n = 26) and smokeless (n = 9) coal. Gene-expression was profiled via microarrays, and changes associated with coal type were correlated to household levels of fine particulate matter (PM2.5) and polycyclic aromatic hydrocarbons (PAHs). Expression levels of 282 genes were altered with smoky versus smokeless coal exposure (P < 0.005), including the 2-fold increase of proinflammatory IL8 and decrease of proapoptotic CASP3. This signature was more correlated with carcinogenic PAHs (e.g. Benzo[a]pyrene; r = 0.41) than with non-carcinogenic PAHs (e.g. Fluorene; r = 0.08) or PM2.5 (r = 0.05). Genes altered with smoky coal exposure were concordantly enriched with tobacco exposure in previously profiled buccal biopsies of smokers and non-smokers (GSEA, q < 0.05). This is the first study to identify a signature of buccal epithelial gene-expression that is associated with smoky coal exposure, which in part is similar to the molecular response to tobacco smoke, thereby lending biologic plausibility to prior epidemiological studies that have linked this exposure to lung cancer risk.

Hair Manganese as an Exposure Biomarker among Welders

Quantifying exposure and dose to manganese (Mn) containing airborne particles in welding fume presents many challenges. Common biological markers such as Mn in blood or Mn in urine have not proven to be practical biomarkers even in studies where positive associations were observed. However, hair Mn (MnH) as a biomarker has the advantage over blood and urine that it is less influenced by short-term variability of Mn exposure levels because of its slow growth rate. The objective of this study was to determine whether hair can be used as a biomarker for welders exposed to manganese. Hair samples (1cm) were collected from 47 welding school students and individual air Mn (MnA) exposures were measured for each subject. MnA levels for all days were estimated with a linear mixed model using welding type as a predictor. A 30-day time-weighted average MnA (MnA30d) exposure level was calculated for each hair sample. The association between MnH and MnA30d levels was then assessed. A linear relationship was observed between log-transformed MnA30d and log-transformed MnH. Doubling MnA30d exposure levels yields a 20% (95% confidence interval: 11-29%) increase in MnH. The association was similar for hair washed following two different wash procedures designed to remove external contamination. Hair shows promise as a biomarker for inhaled Mn exposure given the presence of a significant linear association between MnH and MnA30d levels.

Abstract 840: Occupational exposure to trichloroethylene and LINE-1 methylation

Trichloroethylene (TCE) is a volatile chlorinated organic compound that is commonly used in industrial settings as a degreaser. Epidemiologic studies suggest that TCE exposure is associated with an increased risk of kidney cancer and may also be associated with non-Hodgkin lymphoma. However, the mechanisms for these associations are still not clear. To evaluate the relationship between occupational exposure to trichloroethylene (TCE) and LINE-1 methylation, a measure of global methylation, we conducted a cross-sectional molecular epidemiology study of 79 workers exposed to TCE and 81 comparable unexposed controls in Guangdong, China. Personal air exposure measurements and urine samples were collected prior to phlebotomy. The urine TCE metabolite, trichloroacetic acid (TCA), was measured by liquid chromatography electrospray ionization tandem mass spectrometry in urine samples and LINE-1 methylation was assessed by pyrosequencing DNA isolated from peripheral blood. LINE-1 methylation levels [median (range) in percent] were 78.40 (75.80-81.20) in controls, 77.80 (76.10-81.00) in lower exposed, and 77.50 (74.20-80.20) in higher exposed workers based on median urine TCA level (p trend = 0.012). These results suggest that TCE may be associated with a decrease in global methylation measured by the LINE-1 assay. Gene-specific methylation is currently being conducted to follow up these findings.

Citation Format: Wei Hu, Luoping Zhang, Christopher Kim, Xiaojiang Tang, Sungkyoon Kim4, Bryan Bassig, Wei-Jie Seow, Min Shen, Chuangyi Qiu, Yechen Ge, Boris Reiss, Mark Purdue, Lee Moore, Laiyu Li, Fei Yue, Hanlin Huang, Martyn T. Smith, Roel Vermeulen, Nathaniel Rothman, Qing Lan. Occupational exposure to trichloroethylene and LINE-1 methylation. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 840. doi:10.1158/1538-7445.AM2015-840

Abstract 829: Circulating immune/inflammation markers in Chinese workers occupationally exposed to formaldehyde

Background: Formaldehyde has been proposed to be a human myeloid leukemogen. However, the exact mechanism for the basis for this link is still debated. We aimed to evaluate whether circulating immune/inflammation markers were different in workers occupationally exposed to formaldehyde.

Methods: Using a multiplexed bead-based assay, we measured serum levels of 38 immune/inflammation markers in a cross-sectional study of 43 formaldehyde-exposed and 51 unexposed factory workers in Guangdong, China. Linear regression models adjusting for potential confounders were used to compare marker levels in exposed and unexposed workers.

Results: We found significantly lower circulating levels of four markers among exposed factory workers compared to unexposed controls that remained significant after adjusting for multiple comparisons, including thymus and activation regulated chemokine (TARC;52pg/ml in exposed versus 75pg/ml in controls,P = 0.0015), TNF-related apoptosis-inducing ligand (TRAIL;11.7pg/ml in exposed versus 22.1pg/ml in controls,P = 0.011), C-reactive protein (CRP;797.3ng/ml in exposed versus 3269.1ng/ml in controls,P = 0.013) and chemokine (C-X-C motif) ligand 11 (CXCL11;36.2pg/ml in exposed versus 48.4pg/ml in controls,P = 0.017), suggesting immunosuppression among formaldehyde-exposed workers.

Conclusions: Our findings are consistent with recently emerging understanding that immunosuppression might be associated with myeloid diseases. These findings, if replicated in a larger study, may provide insights into the mechanism by which formaldehyde promotes leukemogenesis.

Citation Format: Qing Lan, Wei Jie Seow, Luoping Zhang, Roel Vermeulen, Xiaojiang Tang, Wei Hu, Bryan A. Bassig, Zhiying Ji, Meredith S. Shiels, Troy J. Kemp, Min Shen, Chuangyi Qiu, Boris Reiss, Laura Beane Freeman, Aaron Blair, Christopher Kim, Weihong Guo, Cuiju Wen, Laiyu Li, Ligia A. Pinto, Hanlin Huang, Martyn T. Smith, Allan Hildesheim, Nathaniel Rothman. Circulating immune/inflammation markers in Chinese workers occupationally exposed to formaldehyde. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 829. doi:10.1158/1538-7445.AM2015-829

Circulating immune/inflammation markers in Chinese workers occupationally exposed to formaldehyde

BACKGROUND

Formaldehyde has been classified as a human myeloid leukemogen. However, the mechanistic basis for this association is still debated.

OBJECTIVES

We aimed to evaluate whether circulating immune/inflammation markers were altered in workers occupationally exposed to formaldehyde.

METHODS

Using a multiplexed bead-based assay, we measured serum levels of 38 immune/inflammation markers in a cross-sectional study of 43 formaldehyde-exposed and 51 unexposed factory workers in Guangdong, China. Linear regression models adjusting for potential confounders were used to compare marker levels in exposed and unexposed workers.

RESULTS

We found significantly lower circulating levels of two markers among exposed factory workers compared with unexposed controls that remained significant after adjusting for potential confounders and multiple comparisons using a false discovery rate of 10%, including chemokine (C-X-C motif) ligand 11 (36.2 pg/ml in exposed versus 48.4 pg/ml in controls, P = 0.0008) and thymus and activation regulated chemokine (52.7 pg/ml in exposed versus 75.0 pg/ml in controls, P = 0.0028), suggesting immunosuppression among formaldehyde-exposed workers.

CONCLUSIONS

Our findings are consistent with recently emerging understanding that immunosuppression might be associated with myeloid diseases. These findings, if replicated in a larger study, may provide insights into the mechanisms by which formaldehyde promotes leukemogenesis.

Chromosome-wide aneuploidy study of cultured circulating myeloid progenitor cells from workers occupationally exposed to formaldehyde

Formaldehyde (FA) is an economically important industrial chemical to which millions of people worldwide are exposed environmentally and occupationally. Recently, the International Agency for Cancer Research concluded that there is sufficient evidence that FA causes leukemia, particularly myeloid leukemia. To evaluate the biological plausibility of this association, we employed a chromosome-wide aneuploidy study approach, which allows the evaluation of aneuploidy and structural chromosome aberrations (SCAs) of all 24 chromosomes simultaneously, to analyze cultured myeloid progenitor cells from 29 workers exposed to relatively high levels of FA and 23 unexposed controls. We found statistically significant increases in the frequencies of monosomy, trisomy, tetrasomy and SCAs of multiple chromosomes in exposed workers compared with controls, with particularly notable effects for monosomy 1 [P = 6.02E-06, incidence rate ratio (IRR) = 2.31], monosomy 5 (P = 9.01E-06; IRR = 2.24), monosomy 7 (P = 1.57E-05; IRR = 2.17), trisomy 5 (P = 1.98E-05; IRR = 3.40) and SCAs of chromosome 5 (P = 0.024; IRR = 4.15). The detection of increased levels of monosomy 7 and SCAs of chromosome 5 is particularly relevant as they are frequently observed in acute myeloid leukemia. Our findings provide further evidence that leukemia-related cytogenetic changes can occur in the circulating myeloid progenitor cells of healthy workers exposed to FA, which may be a potential mechanism underlying FA-induced leukemogenesis.

Polycyclic aromatic hydrocarbon exposure in household air pollution from solid fuel combustion among the female population of Xuanwei and Fuyuan counties, China

Exposure to polycyclic aromatic hydrocarbons (PAHs) from burning "smoky" (bituminous) coal has been implicated as a cause of the high lung cancer incidence in the counties of Xuanwei and Fuyuan, China. Little is known about variations in PAH exposure from throughout the region nor how fuel source and stove design affects exposure. Indoor and personal PAH exposure resulting from solid fuel combustion in Xuanwei and Fuyuan was investigated using repeated 24 h particle bound and gas-phase PAH measurements, which were collected from 163 female residents of Xuanwei and Fuyuan. 549 particle bound (283 indoor and 266 personal) and 193 gas phase (all personal) PAH measurements were collected. Mixed effect models indicated that PAH exposure was up to 6 times higher when burning smoky coal than smokeless coal and varied by up to a factor of 3 between different smoky coal geographic sources. PAH measurements from unventilated firepits were up to 5 times that of ventilated stoves. Exposure also varied between different room sizes and season of measurement. These findings indicate that PAH exposure is modulated by a variety of factors, including fuel type, coal source, and stove design. These findings may provide valuable insight into potential causes of lung cancer in the area.

Heterogeneity in coal composition and implications for lung cancer risk in Xuanwei and Fuyuan counties, China

BACKGROUND

Xuanwei and Fuyuan counties in Yunnan Province, China have among the highest lung cancer rates in the country. This has been associated with the domestic combustion of bituminous coal (referred to as "smoky" coal). Additionally, significant geographical variation in cancer rates among smoky coal users has been observed, suggesting heterogeneity in fuel source composition and/or combustion characteristics. Research thus far has indicated that smoky coal emits high levels of polycyclic aromatic hydrocarbons (PAHs) and contains high concentrations of fine grained crystalline quartz, however, much of this research is limited in terms of sample size and geographic scope. In order to more fully characterise geochemical and elemental compositions of smoky and smokeless coal use in Xuanwei and Fuyuan, we carried out a large exposure assessment study in households in this region.

METHODS

Fuel samples representing smoky and "smokeless" (anthracite, the major alternative coal type in the region) coals were collected from 137 homes in Xuanwei and Fuyuan. Rock-Eval, Leco-CS, XRF analysis and electron microscopy were used to establish hydrocarbon content (to represent volatile organic compounds), major and trace element composition and mineral composition respectively. Heterogeneity in coal characteristics between and within coal types was assessed by the Kruskal-Wallis test.

RESULTS

145 coal samples (116 smoky and 29 smokeless coals) were analysed. Statistically significant differences between smoky and smokeless coals with regard to hydrocarbon content, sulfur, trace elements and mineral composition were observed. Of note, smoky coal contained between 5 and 15 times the amount of volatile organic matter and twice the amount of quartz (including respirable quartz) than smokeless coal. Smoky coal generally had lower levels of trace elements (plus aluminium) than smokeless coal. Significant variation was also observed between smoky coal samples from different geographical areas with regard to hydrocarbon content and elemental composition (including aluminium and silicon).

DISCUSSION

This paper has identified compositional differences between and within smoky and smokeless coals sourced from Xuanwei and Fuyuan counties. A decreased ratio of aluminium to silicon in smoky coal suggests elevated free silica, a finding consistent with observed higher levels of quartz. Elevated volatile organic matter content in smoky coal (when compared to smokeless coal) is consistent with the geochemical expectations for smoky and smokeless coals. These findings also reflect previous observations of elevated volatile compound emissions (notably PAHs) from smoky coal in the area. The observed heterogeneity in coal composition between and within coal types may provide leads to the observed heterogeneity in cancer risk observed in this area.

Zur Kristallstruktur der intermetallischen Phasen MoAs und Mo5AS4

Es wird ein Verfahren zur Herstellung kleiner Einkristalle von MoAs und Mo5As4 durch gerichtete Erstarrung von GaAs- (Mo, As) -Eutektika beschrieben. Die Kristallstrukturen von MoAs und Mo5As4 wurden auf röntgenographischem Weg an Hand von Einkristallen und Pulverproben untersucht. MoAs kristallisiert im MnP-Struktur-Typ mit den Gitterkonstanten a = 5,978Å, b=3,360Å, c = 6,415 A. Mo5As4 besitzt eine Ti5Te4-Struktur; die Gitterkonstanten betragen: α = 9,591 A, c = 3,281Å.

Die Struktur von Mo5As4 wird diskutiert.

Personal and indoor PM2.5 exposure from burning solid fuels in vented and unvented stoves in a rural region of China with a high incidence of lung cancer

The combustion of biomass and coal is the dominant source of household air pollution (HAP) in China, and contributes significantly to the total burden of disease in the Chinese population. To characterize HAP exposure related to solid fuel use and ventilation patterns, an exposure assessment study of 163 nonsmoking female heads of households enrolled from 30 villages was conducted in Xuanwei and Fuyuan, two neighboring rural counties with high incidence of lung cancer due to the burning of smoky coal (a bituminous coal, which in health evaluations is usually compared to smokeless coal--an anthracite coal available in some parts of the area). Personal and indoor 24-h PM2.5 samples were collected over two consecutive days in each household, with approximately one-third of measurements retaken in a second season. The overall geometric means (GM) of personal PM2.5 concentrations in Xuanwei and Fuyuan were 166 [Geometric Standard Deviation (GSD):2.0] and 146 (GSD:1.9) μg/m(3), respectively, which were similar to the indoor PM2.5 air concentrations [GM(GSD):162 (2.1) and 136 (2.0) μg/m(3), respectively]. Personal PM2.5 was moderately highly correlated with indoor PM2.5 (Spearman r = 0.70, p < 0.0001). Burning wood or plant materials (tobacco stems, corncobs etc.) resulted in the highest personal PM2.5 concentrations (GM:289 and 225 μg/m(3), respectively), followed by smoky coal, and smokeless coal (GM:148 and 115 μg/m(3), respectively). PM2.5 levels of vented stoves were 34-80% lower than unvented stoves and firepits across fuel types. Mixed effect models indicated that fuel type, ventilation, number of windows, season, and burning time per stove were the main factors related to personal PM2.5 exposure. Lower PM2.5 among vented stoves compared with unvented stoves and firepits is of interest as it parallels the observation of reduced risks of malignant and nonmalignant lung diseases in the region.

Occupational exposure to trichloroethylene and serum concentrations of IL-6, IL-10, and TNF-alpha

To evaluate the immunotoxicity of trichloroethylene (TCE), we conducted a cross-sectional molecular epidemiology study in China of workers exposed to TCE. We measured serum levels of IL-6, IL-10, and TNF-α, which play a critical role in regulating various components of the immune system, in 71 exposed workers and 78 unexposed control workers. Repeated personal exposure measurements were taken in workers before blood collection using 3 M organic vapor monitoring badges. Compared to unexposed workers, the serum concentration of IL-10 in workers exposed to TCE was decreased by 70% (P = 0.001) after adjusting for potential confounders. Further, the magnitude of decline in IL-10 was >60% and statistically significant in workers exposed to <12 ppm as well as in workers with exposures ≥ 12 ppm of TCE, compared to unexposed workers. No significant differences in levels of IL-6 or TNF-α were observed among workers exposed to TCE compared to unexposed controls. Given that IL-10 plays an important role in immunologic processes, including mediating the Th1/Th2 balance, our findings provide additional evidence that TCE is immunotoxic in humans.

Abstract 112: Transcriptomic changes in the oral mucosal epithelium reflect the physiologic response to indoor burning of solid fuels

RATIONALE: Human exposure to indoor smoke emissions from the domestic burning of solid fuels (e.g. coal, wood, plant materials) is a major cause of morbidity and mortality that affects nearly half of the world's population. While epidemiologic studies on the health impact of indoor air pollution (IAP) have yielded valuable insights from the use of various exposure assessments (e.g. personal and area air sampling, urinary metabolites), there is a need to connect these exposure measures to biomarkers of the host's physiologic response to exposure. We have previously shown that gene-expression (GE) profiles in the upper airway epithelium are affected by tobacco smoke. Thus, we sought to determine whether transcriptomic changes in the oral mucosal epithelium might also capture physiologic responses to IAP from the burning of solid fuels. METHODS: Buccal mucosa epithelial cell scrapings were collected from healthy, non-smoking female subjects in rural Xuanwei, China, where female lung cancer rates are among the highest in the world. Benzo(a)pyrene (BaP) exposure levels from indoor burning of solid fuels (primarily coal) for cooking and heating were measured by personal in-home air monitoring. RNA from 18 samples was extracted and processed onto Affymetrix Gene 1.0 ST arrays. Student's t-test and DAVID were used to identify and characterize genes that vary between relatively high levels of BaP exposure (n=8; BaP 99.0 +/- 45.9) and low (n=10; BaP 16.2 +/- 6.1) exposure. Using GSEA, results were compared to independent airway epithelial GE profiles that distinguish current smokers from never smokers and bronchial GE profiles in subjects with and without lung cancer. RESULTS: We identified 227 genes that were differentially expressed between subjects with high and low BaP exposure (p&lt;0.01). Genes elevated with high BaP exposure were enriched for genes involved in the activation of apoptosis and the Toll-Like Receptor Signaling pathway. Genes that we have previously shown to have altered expression in the bronchial, buccal, and nasal epithelium of current smokers relative to never smokers were enriched among the genes associated with BaP exposure (GSEA; q&lt;0.01). There was also a significant enrichment for bronchial epithelial airway genes that were altered in subjects with and without lung cancer in a previous report (GSEA; q&lt;0.01). CONCLUSION: Buccal epithelial GE is affected by BaP exposure in a population that uses coal and other solid fuels for indoor cooking and heating among healthy women in Xuanwei, China. Solid fuel emissions may elicit some of the same transcriptomic responses as cigarette smoke and lung cancer. This demonstrates the feasibility of using non-invasively collected buccal GE profiling to assess physiologic responses to other inhaled toxins such as coal smoke in population-based studies.

Citation Format: Teresa W. Wang, Qing Lan, Bozena Krystyna, Nathaniel Rothman, Roberta Florido, Wei Hu, Katrina Steiling, Gang Liu, Ji Xiao, Yuriy Alekseyev, Jun Xu, Fusheng Wei, H. Dean Hosgood, Boris Reiss, George Downward, Marc Lenburg, Roel Vermeulen, Avrum Spira. Transcriptomic changes in the oral mucosal epithelium reflect the physiologic response to indoor burning of solid fuels. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 112. doi:10.1158/1538-7445.AM2013-112

Occupational exposure to formaldehyde and alterations in lymphocyte subsets

BACKGROUND

Formaldehyde is used in many occupational settings, most notably in manufacturing, health care, and embalming. Formaldehyde has been classified as a human carcinogen, but its mechanism of action remains uncertain.

METHODS

We carried out a cross-sectional study of 43 formaldehyde-exposed workers and 51 unexposed age and sex-matched controls in Guangdong, China to study formaldehyde's early biologic effects. To follow up our previous report that the total lymphocyte count was decreased in formaldehyde-exposed workers compared with controls, we evaluated each major lymphocyte subset (i.e., CD4(+) T cells, CD8(+) T cells, natural killer [NK] cells, and B cells) and T cell lymphocyte subset (CD4(+) naïve and memory T cells, CD8(+) naïve and memory T cells, and regulatory T cells). Linear regression of each subset was used to test for differences between exposed workers and controls, adjusting for potential confounders.

RESULTS

Total NK cell and T cell counts were about 24% (P = 0.037) and 16% (P = 0.0042) lower, respectively, among exposed workers. Among certain T cell subsets, decreased counts among exposed workers were observed for CD8(+) T cells (P = 0.026), CD8(+) effector memory T cells (P = 0.018), and regulatory T cells (CD4(+) FoxP3(+) : P = 0.04; CD25(+) FoxP3(+) : P = 0.008).

CONCLUSIONS

Formaldehyde-exposed workers experienced decreased counts of NK cells, regulatory T cells, and CD8(+) effector memory T cells; however, due to the small sample size; these findings need to be confirmed in larger studies.

Alterations in serum immunoglobulin levels in workers occupationally exposed to trichloroethylene

Trichloroethylene (TCE) has been associated with a variety of immunotoxic effects and may be associated with an increased risk of non-Hodgkin lymphoma (NHL). Altered serum immunoglobulin (Ig) levels have been reported in NHL patients and in animals exposed to TCE. Recently, we reported that occupational exposure to TCE is associated with immunosuppressive effects and immune dysfunction, including suppression of B-cell counts and activation, even at relatively low levels. We hypothesized that TCE exposure would also affect Ig levels in humans. We measured serum levels of IgG, IgM and IgE, by enzyme-linked immunosorbent assay, in TCE-exposed workers (n = 80) and unexposed controls (n = 45), matched by age and gender, in a cross-sectional, molecular epidemiology study of occupational exposure to TCE in Guangdong, China. Exposed workers had about a 17.5% decline in serum levels of IgG compared with unexposed controls (P = 0.0002). Similarly, serum levels of IgM were reduced by about 38% in workers exposed to TCE compared with unexposed controls (P < 0.0001). Serum levels of both IgG and IgM were significantly decreased in workers exposed to TCE levels below 12 p.p.m., the median exposure level. Adjustment for B-cell counts had minimal impact on our findings. IgE levels were not significantly different between exposed and control subjects. These results provide further evidence that TCE is immunotoxic at relatively low exposure levels and provide additional biologic plausibility for the reported association of TCE with NHL.

Elevated urinary levels of kidney injury molecule-1 among Chinese factory workers exposed to trichloroethylene

Epidemiological studies suggest that trichloroethylene (TCE) exposure may be associated with renal cancer. The biological mechanisms involved are not exactly known although nephrotoxicity is believed to play a role. Studies on TCE nephrotoxicity among humans, however, have been largely inconsistent. We studied kidney toxicity in Chinese factory workers exposed to TCE using novel sensitive nephrotoxicity markers. Eighty healthy workers exposed to TCE and 45 comparable unexposed controls were included in the present analyses. Personal TCE exposure measurements were taken over a 2-week period before urine collection. Ninety-six percent of workers were exposed to TCE below the current US Occupational Safety and Health Administration permissible exposure limit (100 ppm 8h TWA), with a mean (SD) of 22.2 (35.9) ppm. Kidney injury molecule-1 (KIM-1) and Pi-glutathione S transferase (GST) alpha were elevated among the exposed subjects as compared with the unexposed controls with a strong exposure-response association between individual estimates of TCE exposure and KIM-1 (P < 0.0001). This is the first report to use a set of sensitive nephrotoxicity markers to study the possible effects of TCE on the kidneys. The findings suggest that at relatively low occupational exposure levels a toxic effect on the kidneys can be observed. This finding supports the biological plausibility of linking TCE exposure and renal cancer.

Decreased Numbers of CD4(+) Naive and Effector Memory T Cells, and CD8(+) Naïve T Cells, are Associated with Trichloroethylene Exposure

Trichloroethylene (TCE) is a volatile chlorinated organic compound that is commonly used as a solvent for lipophilic compounds. Although recognized as an animal carcinogen, TCE's carcinogenic potential in humans is still uncertain. We have carried out a cross-sectional study of 80 workers exposed to TCE and 96 unexposed controls matched on age and sex in Guangdong, China to study TCE's early biologic effects. We previously reported that the total lymphocyte count and each of the major lymphocyte subsets (i.e., CD4(+) T cells, CD8(+) T cells, natural killer cells, and B cells) were decreased in TCE-exposed workers compared to controls, suggesting a selective effect on lymphoid progenitors, and/or lymphocyte survival. To explore which T lymphocyte subsets are affected in the same study population, we investigated the effect of TCE exposure on the numbers of CD4(+) naïve and memory T cells, CD8(+) naïve and memory T cells, and regulatory T cells by FACS analysis. Linear regression of each subset was used to test for differences between exposed workers and controls adjusting for potential confounders. We observed that CD4(+) and CD8(+) naïve T cell counts were about 8% (p = 0.056) and 17% (p = 0.0002) lower, respectively, among exposed workers. CD4(+) effector memory T cell counts were decreased by about 20% among TCE-exposed workers compared to controls (p = 0.001). The selective targeting of TCE on CD8(+) naive and possibly CD4(+) naive T cells, and CD4(+) effector memory T cells, provide further insights into the immunosuppression-related response of human immune cells upon TCE exposure.

Combustion-derived nanoparticle exposure and household solid fuel use in Xuanwei and Fuyuan, China

Combustion-derived nanoparticles (CDNPs) have not been readably measurable until recently. We conducted a pilot study to determine CDNP levels during solid fuel burning. The aggregate surface area of CDNP (μm(2)/cm(3)) was monitored continuously in 15 Chinese homes using varying fuel types (i.e. bituminous coal, anthracite coal, wood) and stove types (i.e. portable stoves, stoves with chimneys, firepits). Information on fuel burning activities was collected and PM(2.5) levels were measured. Substantial exposure differences were observed during solid fuel burning (mean: 228.1 μm(2)/cm(3)) compared to times without combustion (mean: 14.0 μm(2)/cm(3)). The observed levels during burning were reduced by about four-fold in homes with a chimney (mean: 92.1 μm(2)/cm(3); n = 9), and effects were present for all fuel types. Each home's CDNP measurement was only moderately correlated with the respective PM(2.5) measurements (r (2) = 0.43; p = 0.11). Our results indicate that household coal and wood burning contributes to indoor nanoparticle levels, which are not fully reflected in PM(2.5) measurements.

Abstract 1876: Assessment of exposure to potential lung carcinogens in Xuanwei and Fuyuan, China: Particulate exposure from cooking and heating stoves

Residents in Xuanwei, China have the highest lung cancer incidence rates in China for both men and women, despite the fact that almost all women are non-smokers. Several lines of research have provided strong support that the excess lung cancer rate in this region is caused primarily by emissions from smoky coal exposure. We have carried out a hospital-based case-control study of non-smoking female lung cancer in Xuanwei and its neighboring county, Fuyuan, to identify which constituents of coal combustion emissions and other indoor environmental exposures are causing the high lung cancer rates in this region. In order to develop individual estimates of exposure to known or suspected lung carcinogens, we designed a comprehensive exposure assessment study of 163 households in this region to evaluate exposure to PAHs, PM2.5, silica, and other exposures from coal and wood burning. Homes that used three main fuel types (i.e., smoky coal, smokeless coal and wood), and eight stove types [e.g., firepit, fixed or portable stove, with or without ventilation] were identified and households were sampled on two consecutive days. Up to 30 households were selected for each combination of fuel and stove type. A subgroup of 53 households was measured at two time-points during the study year (e.g. summer and winter). The female head of each household was asked to wear a 24-hour personal PM2.5 air sampler at the same time that 24-hour area air sampling was employed in the main living area. Personal and area particulate matter samples (PM2.5) were collected in each home. These samples were also used to quantify particle bound PAHs including BaP (by GC/MS), elemental components (by XRF and ICP/MS), and silica (by XRD). XAD2 samples were collected for the quantification of gaseous PAHs. Other samples, including radon and organic vapor, fuel and ash were also obtained. We also collected information on potential factors that could influence exposure, such as house characteristics, stove type, fuel type and use, amount of fuel used, amount of time spent in each room. Initial analyses show that people using wood burned in firepits were exposed to the highest levels of PM2.5 measured in area (536.3±370.5 µg/m3) and personal samples(419.8±283.3 µg/m3). Burning smokeless coal in a high stove with a chimney was associated with the lowest exposure to PM2.5 (62.2±34.1 µg/m3, 62.5±29.9 µg/m3 for area and personal samples, respectively). These data show that there is a wide range of exposure to PM2.5 in this population. These data and other exposure information from this study will be used in the future to model environmental exposures and risk of lung cancer in this special, high risk population.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1876. doi:10.1158/1538-7445.AM2011-1876

Abstract 4646: Occupational exposure to trichloroethylene and plasma concentrations of IL6, IL10, and TNF alpha

Trichloroethylene (TCE) is a chlorinated solvent primarily used as a vapor degreaser in many industries. TCE is currently classified by IARC as probably carcinogenic to humans (Group 2A), and has been associated with non-Hodgkin lymphoma (NHL) in some epidemiological studies, although the findings have been inconsistent. To explore the biologic plausibility that TCE may be a lymphomagen, we conducted a cross-sectional study of workers exposed to TCE in Guangzhou, China and tested if plasma levels of the cytokines IL6, IL10, and TNF-alpha, which play a critical role in regulating various components of the immune system, were altered in exposed workers. We enrolled 80 workers from factories where TCE was used as well as 96 unexposed controls matched by sex and age from food and clothes manufacturing factories. Personal exposure measurements were taken over a three-week period, two to three per subject, in the exposed subjects for a full work shift using a 3M badge, as well as for a subgroup of the control workers. Blood samples were collected from each subject, and plasma concentrations of IL6, IL10, and TNF-alpha were measured by ELISA. Linear regression using the natural logarithm of each endpoint and adjusting for potential confounders was used to test for differences in marker concentrations between controls and exposed workers. The mean TCE exposure level in exposed subjects was 23.9 ppm (95% C.I. 14.2-33.6 ppm). Compared to unexposed workers, the plasma concentration of IL10 in workers exposed to TCE was decreased by more than 50% compared to controls (p=0.003), while there was no difference in levels of IL6 or TNF-alpha in TCE exposed workers and controls. IL10 plays a critical role in mediating the Th1/Th2 balance, apoptosis, and regulation of inflammation. Genotypes associated with altered IL10 expression have also been associated with the development and progression of NHL. Given that immunologic alterations are suspected to play a role in lymphomagenesis, and IL10 plays an important role in immunologic processes, our findings provide some support for the biologic plausibility that TCE is associated with lymphoma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4646. doi:10.1158/1538-7445.AM2011-4646

CSA: the online portal for determining the clinical standing of ceramic restorations in practice

For the individual dentist, the Ceramic Success Analysis (CSA) is atried and tested internet-based platform for monitoring the clinical success of all-ceramic restorations. After compiling an insertion protocol and recording the findings from regular clinical follow-up examinations, an analysis follows which culminates in the re-evaluation of the indication and the treatment approach. The evaluations of the 12-year results confirm a high success rate for all-ceramic restorations. Factors which influence the long-term success are: tooth vitality, an indicated crown, the use of a two-bottle dentin adhesive, and the placement of rubber-dam in the adhesive cementation technique.

Occupational exposure to trichloroethylene is associated with a decline in lymphocyte subsets and soluble CD27 and CD30 markers

Occupational cohort and case-control studies suggest that trichloroethylene (TCE) exposure may be associated with non-Hodgkin lymphoma (NHL) but findings are not consistent. There is a need for mechanistic studies to evaluate the biologic plausibility of this association. We carried out a cross-sectional molecular epidemiology study of 80 healthy workers that used TCE and 96 comparable unexposed controls in Guangdong, China. Personal exposure measurements were taken over a three-week period before blood collection. Ninety-six percent of workers were exposed to TCE below the current US Occupational Safety and Health Administration Permissible Exposure Limit (100 p.p.m. 8 h time-weighted average), with a mean (SD) of 22.2 (36.0) p.p.m. The total lymphocyte count and each of the major lymphocyte subsets including CD4+ T cells, CD8+ T cells, natural killer (NK) cells and B cells were significantly decreased among the TCE-exposed workers compared with controls (P < 0.05), with evidence of a dose-dependent decline. Further, there was a striking 61% decline in sCD27 plasma level and a 34% decline in sCD30 plasma level among TCE-exposed workers compared with controls. This is the first report that TCE exposure under the current Occupational Safety and Health Administration workplace standard is associated with a decline in all major lymphocyte subsets and sCD27 and sCD30, which play an important role in regulating cellular activity in subsets of T, B and NK cells and are associated with lymphocyte activation. Given that altered immunity is an established risk factor for NHL, these results add to the biologic plausibility that TCE is a possible lymphomagen.

Occupational exposure to formaldehyde, hematotoxicity, and leukemia-specific chromosome changes in cultured myeloid progenitor cells

There are concerns about the health effects of formaldehyde exposure, including carcinogenicity, in light of elevated indoor air levels in new homes and occupational exposures experienced by workers in health care, embalming, manufacturing, and other industries. Epidemiologic studies suggest that formaldehyde exposure is associated with an increased risk of leukemia. However, the biological plausibility of these findings has been questioned because limited information is available on the ability of formaldehyde to disrupt hematopoietic function. Our objective was to determine if formaldehyde exposure disrupts hematopoietic function and produces leukemia-related chromosome changes in exposed humans. We examined the ability of formaldehyde to disrupt hematopoiesis in a study of 94 workers in China (43 exposed to formaldehyde and 51 frequency-matched controls) by measuring complete blood counts and peripheral stem/progenitor cell colony formation. Further, myeloid progenitor cells, the target for leukemogenesis, were cultured from the workers to quantify the level of leukemia-specific chromosome changes, including monosomy 7 and trisomy 8, in metaphase spreads of these cells. Among exposed workers, peripheral blood cell counts were significantly lowered in a manner consistent with toxic effects on the bone marrow and leukemia-specific chromosome changes were significantly elevated in myeloid blood progenitor cells. These findings suggest that formaldehyde exposure can have an adverse effect on the hematopoietic system and that leukemia induction by formaldehyde is biologically plausible, which heightens concerns about its leukemogenic potential from occupational and environmental exposures.

Powdering or spraying

Application--especially in combination with the new camera--is so easy and advantageous that it has advanced to become the standard procedure in our practice. Potential for improvement still exists in the stiffness of the cannula, in a release mechanism located separately from the cannula and in the impudent demand to completely do away with powder and spray. Despite announcements to the contrary by alternative systems, the fulfilment of this desire appears to be a long way off.

Challenges of exposure assessment for health studies in the aftermath of chemical incidents and disasters

Exposure assessment during and after acute chemical incidents and disasters is essential for health studies that may follow. During chemical incidents, the focus usually lies on risk assessment and afterward attention shifts toward possible (long-term) health effects. This may lead to insufficient available data on exposure to study the association between exposure and health outcome, and collection of additional exposure data is often required. Literature on health studies conducted after several chemical incidents was reviewed to obtain better insight on the needs of health studies. Four different types of scenarios were distinguished based on when exposure data were collected and the exposure data used for health studies. These four scenarios gave insight on exposure data needed for conclusive health studies and when different methods of exposure data collection should be used. Literature indicated that adequate and rapid exposure assessment during chemical incidents is vital for health studies, because data that are not collected during or directly after an incident may be irretrievably lost. Poor exposure assessment is not always the only problem in health studies. Problems in health studies including poor exposure assessment may be prevented when the general design and needs of health studies are taken into account when designing contingency plans. Together with measures that will help facilitate funding, design, and coordination of health studies, disaster management programs should, among others, prepare for methods that lead to a swift identification of released substances, determination of concentrations and dispersion of released substances, designing basic questionnaire outlines, and rapid evaluation of the usefulness and necessity of employing biological sampling.