Exogenous Exposure Research Articles

Somatic mutations and clonal dynamics in healthy and cirrhotic human liver.

SummaryThe commonest causes of chronic liver disease are excess alcohol intake, viral hepatitis or non-alcoholic fatty liver disease, with the clinical spectrum ranging in severity from hepatic inflammation through cirrhosis to liver failure or hepatocellular carcinoma. The hepatocellular carcinoma genome exhibits diverse mutational signatures, resulting in recurrent mutations across >20-30 cancer genes1–7. Stem cells from normal livers have low mutation burden and limited diversity of signatures8, suggesting that the complexity of hepatocellular carcinoma arises during progression to chronic liver disease and subsequent malignant transformation. We sequenced whole genomes of 482 microdissections of 100-500 hepatocytes from 5 normal and 9 cirrhotic livers. Compared to normal liver, cirrhotic liver had higher mutation burden. Although rare in normal hepatocytes, structural variants, including chromothripsis, were prominent in cirrhosis. Driver mutations, both point mutations and structural variants, affected 1-5% clones. Clonal expansions millimetres in diameter occurred in cirrhosis, sequestered by bands of fibrosis engirdling regenerative nodules. Some mutational signatures were universal and equally active in both non-malignant hepatocytes and HCC; some were substantially more active in HCC than chronic liver disease; and others, arising from exogenous exposures, were present in a subset of patients. Up to 10-fold within-patient variation in activity of exogenous signatures existed between adjacent cirrhotic nodules, arising from clone-specific and microenvironmental forces. Synchronous hepatocellular carcinomas exhibited the same mutational signatures as background cirrhotic liver, but with higher burden. Somatic mutations chronicle the exposures, toxicity, regeneration and clonal structure of liver tissue as it progresses from health to disease.

Assessment of plasma metabolomic biomarkers in various pediatric diseases

OPS 59: The Exposome: progress in methods and applications, Room 412, Floor 4, August 28, 2019, 1:30 PM - 3:00 PM Background: Metabolites that are direct read-outs of the functional status of cells, tissues, and organs can be more closely associated with phenotype compared to other omics profiles. Previous studies showed the analytical validity of metabolomic platforms and demonstrated a utility in interpreting the impact of genetic variants. Methods: To explore the utility of metabolomics in the context of precision medicine, we used an untargeted ultrahigh performance liquid chromatography-tandem mass spectroscopy to characterize plasma samples collected from generally healthy individuals and a deeply phenotyped cohort with various pediatric diseases. Results: A total of 1244 metabolites including 224 xenobiotic compounds were quantitatively measured for 169 individuals and thus revealed complex correlation structure within and between metabolic pathways. As proofs-of-concept, perturbations of phenylalanine and tyrosine metabolic pathways in a patient with phenylketonuria and carbohydrate metabolism in patients with diabetes mellitus were recapitulated as well as highlighting other biomarkers such as 1,5−anhydroglucitol for monitoring glycemic control. We discovered multiple metabolites that were significantly associated with different diseases using an exposome-wide association analysis framework. Amino acids showed significantly changed in patients with congenital heart diseases, and multiple lipid compounds were significant for Crohn’s disease. Notably, gut microbial products showed different concentrations with the use of antibiotics. Each xenobiotic compound showed a distinct correlation pattern with endogenous metabolites. Conclusions: Untargeted metabolomics could be a powerful precision medicine platform in itself or in combination with WES. The impact of exogenous exposures such as microbial products, drugs and environmental toxicants can be directly estimated by monitoring internal exposome, enabling the discovery of novel diagnosis and treatment biomarkers in diverse diseases. A repository of metabolomics data is required, which will enable the comparison between different platforms and concentrations of thousands of metabolites across individuals.

The Relationship Between Exogenous Exposure to “The Real Cost” Anti-Smoking Campaign and Campaign-Targeted Beliefs

Though previous evaluations of “The Real Cost” anti-smoking campaign demonstrate effects on anti-smoking beliefs and behaviors, results rely on self-reported recall as a measure of exposure and are thus open to reverse causation concerns. Exogenous measures of exposure, assessed independently of outcomes, support stronger causal inferences. In this study, we examined the relationship between Target Rating Points (TRPs) for specific ads available over four-week periods and anti-smoking beliefs in a national sample of adolescent nonsmokers and experimenters (n = 4,780). Results demonstrate positive relationships between TRPs for ads targeting two of four belief categories tested (Control and Chemical; p < .05) and targeted-belief endorsement. Furthermore, moderation models indicate that ad-specific TRPs affected targeted beliefs more than non-targeted beliefs for those Control- and Chemical-targeted ads (p < .01). Findings support a claim of campaign effects while reducing concerns about reverse causal direction and the influence of unmeasured confounders.

Characterization of a head and neck cancer-derived cell line panel confirms the distinct TP53-proficient copy number-silent subclass

IntroductionHead and neck squamous cell carcinomas (HNSCC) arise in the mucosal lining of the upper aerodigestive tract. Risk factors are exogenous carcinogen exposure, human papillomavirus (HPV) infection, and genetic predisposition such as Fanconi anemia (FA). Clinically, tumors are stratified based on stage, site and HPV-status. The majority of HPV-positive and -negative HNSCC is characterized by frequent copy number (CN) changes and an abrogated p53-pathway. A third genetically-defined HPV-negative subclass of HNSCC is emerging: tumors that lack gross chromosomal changes (CN-silent), are mostly TP53-proficient, and have a relatively favorable prognosis. MethodsA representative panel of HPV-positive, HPV-negative and FA-HNSCC-derived cell lines was genetically characterized. ResultsDespite apparent differences in etiology, FA-HNSCC cell lines show comparable genetic alterations as sporadic non-FA-HNSCC-derived cell lines.Furthermore, we identified a near diploid CN-silent HPV-negative HNSCC line: VU-SCC-040. Molecular characterization uncovers the absence of TP53 mutations, a functional p53-pathway and a CASP8 mutation. TP53 gene knockout using CRISPR-Cas9 resulted in resistance to MDM2 inhibition. Whereas p53-status is often proposed as a predictive biomarker for treatment response, TP53-knockout did not change sensitivity to cisplatin, Chk1 and Wee1 inhibition. Additionally, 84 CN-silent tumors were identified in the HNSCC PanCancer cohort and shown to be enriched for female gender, HRAS and CASP8 mutations. ConclusionFA-derived HNSCC cell lines share comparable CN-profiles and mutation patterns as sporadic HPV-negative HNSCC. In contrast, a subclass of CN-silent, HPV-negative and TP53 wild-type HNSCC separates from the majority of HNSCC tumors. We show that VU-SCC-040 is a HNSCC cell model representative of this subclass.

An Integrated Gaussian Graphical Model to evaluate the impact of exposures on metabolic networks

Examining the effects of exogenous exposures on complex metabolic processes poses the unique challenge of identifying interactions among a large number of metabolites. Recent progress in the quantification of the metabolome through mass spectrometry (MS) and nuclear magnetic resonance (NMR) has given rise to high-dimensional biomedical data of specific metabolites that can be leveraged to study their effects in humans. These metabolic interactions can be evaluated using probabilistic graphical models (PGMs), which define conditional dependence and independence between components within and between heterogeneous biomedical datasets. This method allows for the detection and recovery of valuable but latent information that cannot be easily detected by other currently existing methods. Here, we develop a PGM method, referred to as an “Integrated Gaussian Graphical Model (IGGM)”, to incorporate exposure concentrations of seven trace elements—arsenic (As), lead (Pb), mercury (Hg), cadmium (Cd), zinc (Zn), selenium (Se) and copper (Cu—into metabolic networks. We first conducted a simulation study demonstrating that the integration of trace elements into metabolomics data can improve the accuracy of detecting latent interactions of metabolites impacted by exposure in the network. We tested parameters such as sample size and the number of neighboring metabolites of a chosen trace element for their impact on the accuracy of detecting metabolite interactions. We then applied this method to measurements of cord blood plasma metabolites and placental trace elements collected from newborns in the New Hampshire Birth Cohort Study (NHBCS). We found that our approach can identify latent interactions among metabolites that are related to trace element concentrations. Application to similarly structured data may contribute to our understanding of the complex interplay between exposure-related metabolic interactions that are important for human health.

Preliminary Classification of the ABC Transporter Family in Betula halophila and Expression Patterns in Response to Exogenous Phytohormones and Abiotic Stresses

ATP-binding cassette (ABC) transporters comprise a transport system superfamily which is ubiquitous in eukaryotic and prokaryotic cells. In plants, ABC transporters play important roles in hormone transport and stress tolerance. In this study, 15 BhABC transporters encoded by genes identified from the transcriptome of Betula halophila were categorized into four subfamilies (ABCB, ABCF, ABCG, and ABCI) using structural domain and phylogenetic analyses. Upon B. halophila exposure to exogenous phytohormones and abiotic stressors, gene expression patterns and transcriptional responses for each subfamily of genes were obtained using semi-quantitative RT-PCR analysis. The results demonstrated that expression of most genes belonging to ABCB and ABCG subfamilies changed in response to exogenous phytohormone exposures and abiotic stress. These results suggest that BhABC genes may participate in hormone transport and that their expression may be influenced by ABA-dependent signaling pathways involved in abiotic stress responses to various stressors.

Effect of Ethanol-Derived Clove Leaf Extract on the Oxidative Stress Response in Yeast Schizosaccharomyces pombe.

Compared to the widely explored antioxidant activity from the clove bud extract, less data are available regarding the potential pharmacological use of clove leaves. Our study aimed to explore the antioxidant activity of clove leaves extract in the cellular level. Thus, we used the yeast Schizosaccharomyces pombe as model organisms. Our data indicate that, following extract treatment (100 ppm), the viability of the stationary phase cells of S. pombe was higher than without extract and that of calorie restriction treatments. 100 ppm extract treatment also increased cell viability against H2O2-induced oxidative stress. Those data indicate that the extract could promote oxidative stress tolerance response in yeast cells, which occurred either during the stationary phase or due to exogenous exposure. Higher dose of extract (500 ppm) showed opposite effects, as cell viability was lower than that without treatment. Analysis toward the mitochondrial activity revealed that the extract did not induce mitochondrial activity unlike the calorie restriction treatment. Based on our data, clove leaf extract promotes oxidative stress tolerance response in the yeast S. pombe, independent to that mitochondrial adaptive ROS signaling which commonly occurs in calorie restriction-induced oxidative stress tolerance response.

Endogenous sex hormones and risk of venous thromboembolism in young women

BackgroundThe risk of venous thromboembolism (VTE) in young women can predominantly be attributed to exogenous hormone use. The influence of (abnormalities in) endogenous sex hormones, as in polycystic ovary syndrome (PCOS) or primary ovarian insufficiency (POI), on VTE risk is uncertain. ObjectivesTh assess the association between endogenous sex hormone levels and VTE risk. MethodsWomen aged ≤45 years from the MEGA case‐control study who provided a blood sample in the absence of exogenous hormone exposure or pregnancy were included. Sex hormone–binding globulin (SHBG), estradiol, follicle‐stimulating hormone (FSH) and testosterone were measured. The free androgen index (FAI) and estradiol to testosterone ratio (E:T) were calculated. VTE risk was assessed according to quartiles (Qs) of levels and clinical cut‐offs as proxies for PCOS (FAI > 4.5) and POI (FSH > 40 U/L). Logistic regression models were used to estimate adjusted odds ratios (ORs) with 95% confidence intervals (CIs). ResultsSix hundred and sixty‐five women (369 cases; 296 controls) were eligible for the analyses. Testosterone and FSH levels, E:T and POI (FSH > 40 U/L vs FSH ≤ 40 U/L) were not associated with VTE risk. For estradiol, VTE risk was increased with levels in Q4 vs Q1 (OR 1.6; 95% CI 1.0‐2.5). There was a dose‐response relationship between SHBG levels and VTE risk, with the highest OR at Q4 vs Q1: 2.0 (95% CI 1.2‐3.3). FAI > 4.5 (PCOS proxy) vs FAI ≤ 4.5 was associated with increased VTE risk (OR 3.3; 95% CI 0.9‐11.8). ConclusionsEstradiol, SHBG and FAI were associated with VTE risk, suggesting a role for endogenous sex hormones in the pathophysiology of VTE in young women.

Human placental methylome in the interplay of adverse placental health, environmental exposure, and pregnancy outcome.

The placenta is the interface between maternal and fetal circulations, integrating maternal and fetal signals to selectively regulate nutrient, gas, and waste exchange, as well as secrete hormones. In turn, the placenta helps create the in utero environment and control fetal growth and development. The unique epigenetic profile of the human placenta likely reflects its early developmental separation from the fetus proper and its role in mediating maternal–fetal exchange that leaves it open to a range of exogenous exposures in the maternal circulation. In this review, we cover recent advances in DNA methylation in the context of placental function and development, as well as the interaction between the pregnancy and the environment.

A Metabolomics-Inspired Strategy for the Identification of Protein Covalent Modifications.

Identification of protein covalent modifications (adducts) is a challenging task mainly due to the lack of data processing approaches for adductomics studies. Despite the huge technological advances in mass spectrometry (MS) instrumentation and bioinformatics tools for proteomics studies, these methodologies have very limited success on the identification of low abundant protein adducts. Herein we report a novel strategy inspired on the metabolomics workflows for the identification of covalently-modified peptides that consists on LC-MS data preprocessing followed by statistical analysis. The usefulness of this strategy was evaluated using experimental LC-MS data of histones isolated from HepG2 and THLE2 cells exposed to the chemical carcinogen glycidamide. LC-MS data was preprocessed using the open-source software MZmine and potential adducts were selected based on the m/z increments corresponding to glycidamide incorporation. Then, statistical analysis was applied to reveal the potential adducts as those ions are differently present in cells exposed and not exposed to glycidamide. The results were compared with the ones obtained upon the standard proteomics methodology, which relies on producing comprehensive MS/MS data by data dependent acquisition and analysis with proteomics data search engines. Our novel strategy was able to differentiate HepG2 and THLE2 and to identify adducts that were not detected by the standard methodology of adductomics. Thus, this metabolomics driven approach in adductomics will not only open new opportunities for the identification of protein epigenetic modifications, but also adducts formed by endogenous and exogenous exposure to chemical agents.

Pre-Analytical Factors that Affect Metabolite Stability in Human Urine, Plasma, and Serum: A Review.

Metabolomics provides a comprehensive assessment of numerous small molecules in biological samples. As it integrates the effects of exogenous exposures, endogenous metabolism, and genetic variation, metabolomics is well-suited for studies examining metabolic profiles associated with a variety of chronic diseases. In this review, we summarize the studies that have characterized the effects of various pre-analytical factors on both targeted and untargeted metabolomic studies involving human plasma, serum, and urine and were published through 14 January 2019. A standardized protocol was used for extracting data from full-text articles identified by searching PubMed and EMBASE. For plasma and serum samples, metabolomic profiles were affected by fasting status, hemolysis, collection time, processing delays, particularly at room temperature, and repeated freeze/thaw cycles. For urine samples, collection time and fasting, centrifugation conditions, filtration and the use of additives, normalization procedures and multiple freeze/thaw cycles were found to alter metabolomic findings. Consideration of the effects of pre-analytical factors is a particularly important issue for epidemiological studies where samples are often collected in nonclinical settings and various locations and are subjected to time and temperature delays prior being to processed and frozen for storage.

Dihydroxyacetone Exposure Alters NAD(P)H and Induces Mitochondrial Stress and Autophagy in HEK293T Cells.

Dihydroxyacetone phosphate (DHAP) is the endogenous byproduct of fructose metabolism. Excess DHAP in cells can induce advanced glycation end products and oxidative stress. Dihydroxyacetone (DHA) is the triose precursor to DHAP. DHA is used as the active ingredient in sunless tanning products, including aerosolized spray tans, and is formed by the combustion of solvents found in electronic cigarettes. Human exposure to DHA has been increasing as the popularity of sunless tanning products and electronic cigarettes has grown. Topically applied DHA is absorbed through the viable layers of the skin and into the bloodstream. Exogenous exposure to DHA is cytotoxic in immortalized keratinocytes and melanoma cells with cell cycle arrest induced within 24 h and cell death occurring by apoptosis at consumer-relevant concentrations of DHA within 72 h. Less is known about systemic exposures to DHA that occur following absorption through skin, and now through inhalation of the aerosolized DHA used in spray tanning. In the present study, HEK293T cells were exposed to consumer-relevant concentrations of DHA to examine the cytotoxicity of systemic exposures. HEK293T cells were sensitive to consumer-relevant doses of DHA with an IC50 value of 2.4 ± 0.3 mM. However, cell cycle arrest did not begin until 48 h after DHA exposure. DHA-exposed cells showed altered metabolic activity with decreased mitochondrial function and decreased lactate and ATP production observed within 24 h of exposure. Autofluorescent imaging and NAD+ sensors also revealed an imbalance in the redox cofactors NAD+/NADH within 24 h of exposure. Cell death occurred by autophagy indicated by increases in LC3B and SIRT1. Despite DHA's ability to be converted to DHAP and integrated into metabolic pathways, the metabolic dysfunction and starvation responses observed in the HEK293T cells indicate that DHA does not readily contribute to the energetic pool in these cells.

Diffusion of Gender Norms: Evidence from Stalin's Ethnic Deportations

We study horizontal between-group cultural transmission using a unique historical setting, which combines exogenous group exposure with no control over how and whether the representatives of different groups interact. Stalin’s ethnic deportations during WWII moved over 2 million people --- the majority of whom were ethnic Germans and Chechens --- from the Western parts of the USSR to Central Asia and Siberia. As a result, the native population of the deportation destinations was exposed to groups with drastically different gender norms. Combining historical archival data with contemporary surveys, we document that gender norms diffused from deportees to the local population, resulting in changes in attitudes and behavior. Norms of gender equality diffused more than norms of gender discrimination. Identification relies on the fact that, within subnational regions, the local population was fairly homogeneous, while deportation destinations were determined by local demands for manual labor, orthogonal to identity and skills of deportees, making the variation in the group composition of the deportations across destination localities exogenous, conditional on the deportation size and region fixed effects.

Abstract 3928: N-cadherin(CDH2) expression in mesenchymal glioblastoma modulates radiation sensitivity

Abstract Background: Radiation is a mainstay of treatment in patients diagnosed with glioblastoma. Despite maximal surgical and chemo-radiotherapeutic treatment, the disease remains uniformly fatal, with local disease recurrence within the previously radiated field comprising the major pattern of progression. According to the molecular subtyping of GBM, there is a predominance of mesenchymal GBM cells within the recurrent tumor mass, with characteristic increased expression of CD44, N-cadherin, L1CAM, TWIST1 and phosphorylated STAT3. Moreover, these populations of cells are known to be resistant to additional salvage radiation. The current study aims to evaluate the role of N-cadherin in the relative radiation resistance of mesenchymal subtype GBM. Methods: Overall survival data from the TCGA was analyzed using Cox regression hazard ratios based on N-cadherin expression across multiple molecular subtypes of GBM along with age and MGMT covariates. Using the U3035 and U87MG cells, the analyses of N-cadherin expression or exogenous exposure in the setting of external beam radiation were performed via stable shRNA knockdowns or the use of recombinant human N-cadherin ectodomain-Fc fusion proteins in clonogenic survival assays. Orthotopic implantations were performed in NSG mice with the endpoints of overall survival and tumor size, as determined by luciferase imaging. Subcellular localization of RAD51 was accomplished by confocal microscopy. Statistical analyses were performed using SPSS and GraphPad Prism with significance at p&amp;lt;0.05. Results: N-cadherin expression above the median among the mesenchymal subtype of GBM in the TCGA dataset correlated with a significant decrease in overall survival (HR 1.924, p=0.029). The elimination of N-cadherin expression in normally high expressing U3035 GBM cells led to a significant increase in the ability of radiation to induce cell death in clonogenic assay (17.2% U3035 vs 2% U3035 Δ N-cadherin at 8Gy; 12.7% U3035 vs 1.75% U3035 Δ N-cadherin at 20Gy) and an increase in the presence of double stranded DNA breaks (DSBs) on TUNEL assay. N-cadherin ectodomain-Fc fusion protein exposure in U87 cells resulted in a decrease in NSG mouse mean OS (17.6±0.25 days) compared to control radiated mice (22.3±1.1 days). Conversely, N-cadherin knockdown in U3035 cells resulted in further decrease in tumor bioluminescence beyond that seen in 4Gy x 4 radiation treatment of native U3035 xenografts (21% vs 4% of baseline). Conclusions: The reduction of N-cadherin expression in mesenchymal U3035 GBM cells increases the efficacy of radiation-induced cell death. This finding is accompanied by a decrease in the nuclear localization of RAD51 following DSBs induced by ionizing radiation, indicating a potential crosstalk between DNA damage repair mechanisms and calcium dependent cell-cell adhesion. Citation Format: Christopher P. Cifarelli, J. Austin Vargo, Ian MacFawn, Steven M. Frisch. N-cadherin(CDH2) expression in mesenchymal glioblastoma modulates radiation sensitivity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3928.

P004 Primary colonic histoplasmosis secondary to fecal microbiota transplantation in a patient with ulcerative colitis on anti-TNF alpha

INTRODUCTION: Histoplasmosis is a mycotic disease that is most common in patients with a weakened immune system, including those on tumor necrosis factor inhibitors. We present a patient with ulcerative colitis (UC) on infliximab, who had recurrent Clostridium difficile infections (CDI) requiring fecal microbiota transplantation (FMT) and subsequently developed primary colonic histoplasmosis. CASE: We present a 34-year-old woman from Missouri with ulcerative pancolitis on infliximab complicated by recurrent CDI requiring FMT. She was diagnosed with UC at age 32 (March 2015). She failed Mesalamine, Adalimumab (primary non-responder), and developed Azathioprine-induced pancreatitis. Infliximab later replaced Adalimumab with subsequent dose escalation and frequent courses of Prednisone due to refractory disease. The first CDI was diagnosed March 2016. From initial diagnosis, she had 4 CDI positive stools, in addition to a course of diarrhea that was empirically treated as CDI. She completed 4 courses of oral Vancomycin and 2 courses of Fidaxomicin, with initial response but recurrence of diarrhea shortly after antibiotic completion. Due to recurrent CDI, she underwent FMT in April 2017. Two weeks following FMT, she was diagnosed with a pulmonary embolism. Two weeks later, she presented with high grade fevers, hypotension and altered mental status. Labs were notable for rising liver enzymes (peak values: ALP 1,009 u/L, ALT 120 u/L, AST 293 u/L). Abdominal ultrasound did not show signs of cholestatic or hepatic processes. Symptoms continued to worsen despite steroids, fluid resuscitation and broad-spectrum antibiotics. Her course was further complicated by hematochezia and refractory anemia requiring blood transfusions. Cross sectional imaging demonstrated circumferential wall thickening of the proximal ascending colon to the cecum in addition to the previously identified pulmonary embolism. There was no evidence of pneumonia, hilar/mediastinal lymphadenopathy, ground glass opacity, nodules, masses or cavitary lung lesions. Sigmoidoscopy with biopsies demonstrated diffuse colitis. Qualitative serum CMV PCR and urine Histoplasma were checked and resulted positive. Ganciclovir and Amphotericin B liposome were initiated and within 48 hours, liver enzymes began to improve. However, due to worsening clinical course she eventually underwent total abdominal colectomy and partial proctectomy. Both colonic biopsies from sigmoidoscopy and colectomy were positive for Histoplasma and negative for CMV. She was diagnosed with disseminated histoplasmosis, treated with IV Amphotericin B liposome followed by a course of itraconazole, and she fully recovered. Colonic specimens from 5 months and 12 months prior to FMT were retrospectively reviewed and stained negative for histoplasmosis. DISCUSSION: Histoplasmosis in immunocompromised hosts can develop through exogenous exposure or reactivation of latent infection, with the former being more common. Our patient had biopsies from a colonoscopy 5 months preceding FMT which were negative for histoplasmosis, and cross-sectional imaging unrevealing of latent or active pulmonary disease; this suggests that primary colonic histoplasmosis was most likely introduced via FMT, resulting in refractory colitis and requiring total colectomy. Testing FMT donors/stool for histoplasmosis is not standardized and can vary. However, given the frequency of FMT in IBD patients on anti-TNF with recurrent CDI, FMT histoplasmosis screening should be considered.

The retinoic acid hydroxylase Cyp26a1 has minor effects on postnatal vitamin A homeostasis, but is required for exogenous atRA clearance

The all-trans-retinoic acid (atRA) hydroxylase Cyp26a1 is essential for embryonic development and may play a key role in regulating atRA clearance also in adults. We hypothesized that loss of Cyp26a1 activity via inducible knockout in juvenile or adult mice would result in decreased atRA clearance and increased tissue atRA concentrations and atRA-related adverse effects. To test these hypotheses, Cyp26a1 was knocked out in juvenile and adult male and female Cyp26a1 floxed mice using standard Cre-Lox technology and tamoxifen injections. Biochemical and histological methods were used to study the effects of global Cyp26a1 knockout. The Cyp26a1 knockout did not result in consistent histopathological changes in any major organs. Cyp26a1-/- mice gained weight normally and exhibited no adverse phenotypes for up to 1 year after loss of Cyp26a1 expression. Similarly, atRA concentrations were not increased in the liver, testes, spleen, or serum of these mice, and the Cyp26a1 knockout did not cause compensatory induction of lecithin:retinol acetyltransferase (Lrat) or retinol dehydrogenase 11 (Rdh11) mRNA or a decrease in aldehyde dehydrogenase 1a1 (Aldh1a1) mRNA in the liver compared with tamoxifen-treated controls. However, the Cyp26a1-/- mice showed increased bone marrow cellularity and decreased frequency of erythroid progenitor cells in the bone marrow consistent with a retinoid-induced myeloid skewing of hematopoiesis. In addition, the Cyp26a1 knockout decreased clearance of exogenous atRA by 70% and increased atRA half-life 6-fold. These findings demonstrate that despite lacking a major impact on endogenous atRA signaling, Cyp26a1 critically contributes as a barrier for exogenous atRA exposure.

Propaganda and Combat Motivation: Radio Broadcasts and German Soldiers’ Performance in World War II

AbstractWhat explains combat motivation in warfare? Scholars argue that monitoring, material rewards, and punishment alone are insufficient explanations. Further, competing ideological accounts of motivation are also problematic because ideas are difficult to operationalize and measure. To solve this puzzle, the authors combine extensive information from World War II about German soldiers’ combat performance with data about conditionally exogenous potential exposure to Nazi radio propaganda. They find evidence that soldiers with higher potential exposure to propaganda were more likely to be decorated for valor even after controlling for individual socioeconomic factors, home district characteristics like urbanization, and proxies for combat exposure.

Epidemiology and survival of lung cancer in a Latin American cohort.

e13101 Background: Lung cancer epidemiology and survival data is lacking in LA. This information is relevant for understanding regional cancer burden and for designing targeted interventions for cancer control. Methods: Retrospective analysis of lung cancer cases diagnosed at Instituto Nacional de Enfermedades Neoplasicas (INEN) from 2010 to 2014. Data was manually curated from clinical files. Results: 1384 patients were included. Median age at diagnosis was 64 years old (range 20-92) and 51.6% were females. The histologic type was adenocarcinoma, NOS carcinoma, squamous cell carcinoma and small-cell carcinoma in 72.3%, 12.8%, 9.4% and 3.5% of the cases, respectively. The adenocarcinoma/squamous cell carcinoma ratio was 7.7. Among NSCLC cases, most patients presented with advanced disease. Stage III (9.2%) and IV (85.5%) were the most frequent. With a median follow-up of 71.5 months, median overall survival (OS) was 9.2, 7.7 and 8.1 months for adenocarcinoma, NOS carcinoma and squamous carcinoma, respectively. Five-year OS for stage III was 6% and for stage 4, 4%. Detailed results are shown in the table. Conclusions: The epidemiological profile of lung cancer in Peruvian patients is different from that of other countries with a younger age at diagnosis, a preponderance of females over males and an unexpectedly high frequency of adenocarcinomas. This may be in concordance with the low prevalence of tobacco smoking and the high prevalence of EGFR mutations reported for our population as well as with particular exogenous exposures such as biomass fumes from inhouse cooking. The molecular characterization of this cohort of patients is ongoing. [Table: see text]

Study of clinical experience with different approaches to controlled ovarian hyperstimulation: a focus on safety and efficacy

ObjectivesCurrent retrospective cohort study analyses clinical database records of 4792 assisted reproduction procedures to assess the significance of target effectiveness endpoints from a safety perspective.MethodsStimulation protocols with urinary, recombinant or...

Modulation of biochemical and physiological parameters in Hordeum vulgare L. seedlings under the influence of benzyl-butyl phthalate.

BackgroundPhthalates are man-made chemical compounds with numerous applications especially known for their use as plasticizers. They have weak bonding to the polymeric matrix or products in which they are used. Owing to this reason, they are readily released into the environment which makes them ubiquitous. The agricultural soils are also reported to be polluted with phthalates up to a considerable extent which causes adverse effects on flora and fauna. A few studies have been conducted on phthalate-induced phytotoxicity, which has revealed that phthalates affect the quality and yield of edible plants. In the last decades, some crops were analyzed for phthalate-induced adversities; among them, barley was the least explored.MethodsThe present study has investigated the impact of benzyl-butyl phthalate (BBP) on barley (Hordeum vulgare L.) seedlings to address the biochemical, physiological consequences, and toxicological implications. After the exogenous exposure of BBP (viz. 0, 25, 50, 100, 200, 400, 800, 1,600 mg/L) for 7 days, barley seedlings were analyzed for different indices.ResultsThe exposure of BBP mediated a significant (p ≤ 0.05, 0.01) overall elevation in the contents of pigment, proline, soluble protein, carbohydrate, hydrogen peroxide (H2O2), and malondialdehyde (MDA) in shoots and roots of barley seedlings. The activities of superoxide dismutase (SOD), guaiacol peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) were also stimulated significantly in shoots and roots of seedlings against BBP stress except for SOD activity which declined in the roots. The polyphenols (non-enzymatic antioxidants) content was also altered in all the treated concentrations as compared to the control. Furthermore, BBP caused stomatal abnormalities, induced cytotoxicity, and loss of plasma membrane integrity.ConclusionsBBP disturbed the normal physiology of barley which could also affect the yield of the crop under field conditions.