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1.
Sensors (Basel) ; 23(6)2023 Mar 19.
Article in English | MEDLINE | ID: mdl-36991958

ABSTRACT

Defect inspection is essential in the semiconductor industry to fabricate printed circuit boards (PCBs) with minimum defect rates. However, conventional inspection systems are labor-intensive and time-consuming. In this study, a semi-supervised learning (SSL)-based model called PCB_SS was developed. It was trained using labeled and unlabeled images under two different augmentations. Training and test PCB images were acquired using automatic final vision inspection systems. The PCB_SS model outperformed a completely supervised model trained using only labeled images (PCB_FS). The performance of the PCB_SS model was more robust than that of the PCB_FS model when the number of labeled data is limited or comprises incorrectly labeled data. In an error-resilience test, the proposed PCB_SS model maintained stable accuracy (error increment of less than 0.5%, compared with 4% for PCB_FS) for noisy training data (with as much as 9.0% of the data labeled incorrectly). The proposed model also showed superior performance when comparing machine-learning and deep-learning classifiers. The unlabeled data utilized in the PCB_SS model helped with the generalization of the deep-learning model and improved its performance for PCB defect detection. Thus, the proposed method alleviates the burden of the manual labeling process and provides a rapid and accurate automatic classifier for PCB inspections.

2.
Lung Cancer ; 179: 107180, 2023 05.
Article in English | MEDLINE | ID: mdl-36989612

ABSTRACT

OBJECTIVES: E-cigarettes are the most commonly used nicotine containing products among youth. In vitro studies support the potential for e-cigarettes to cause cellular stress in vivo; however, there have been no studies to address whether exposure to e-liquid aerosols can induce cell transformation, a process strongly associated with pre-malignancy. We examined whether weekly exposure of human bronchial epithelial cell (HBEC) lines to e-cigarette aerosols would induce transformation and concomitant changes in gene expression and promoter hypermethylation. MATERIALS AND METHODS: An aerosol delivery system exposed three HBEC lines to unflavored e-liquid with 1.2% nicotine, 3 flavored products with nicotine, or the Kentucky reference cigarette once a week for 12 weeks. Colony formation in soft agar, RNA-sequencing, and the EPIC Beadchip were used to evaluate transformation, genome-wide expression and methylation changes. RESULTS: Jamestown e-liquid aerosol induced transformation of HBEC2 and HBEC26, while unflavored and Blue Pucker transformed HBEC26. Cigarette smoke aerosol transformed HBEC4 and HBEC26 at efficiencies up to 3-fold greater than e-liquids. Transformed clones exhibited extensive reprogramming of the transcriptome with common and distinct gene expression changes observed between the cigarette and e-liquids. Transformation by e-liquids induced alterations in canonical pathways implicated in lung cancer that included axonal guidance and NRF2. Gene methylation, while prominent in cigarette-induced transformed clones, also affected hundreds of genes in HBEC2 transformed by Jamestown. Many genes with altered expression or epigenetic-mediated silencing were also affected in lung tumors from smokers. CONCLUSIONS: These studies show that exposure to e-liquid aerosols can induce a pre-malignant phenotype in lung epithelial cells. While the Food and Drug Administration banned the sale of flavored cartridge-based electric cigarettes, consumers switched to using flavored products through other devices. Our findings clearly support expanding studies to evaluate transformation potency for the major categories of e-liquid flavors to better inform risk from these complex mixtures.


Subject(s)
Electronic Nicotine Delivery Systems , Lung Neoplasms , Tobacco Products , Humans , Adolescent , Nicotine/metabolism , Lung Neoplasms/pathology , Respiratory Aerosols and Droplets , Epithelial Cells , Cell Transformation, Neoplastic/pathology
3.
Gigascience ; 10(10)2021 10 04.
Article in English | MEDLINE | ID: mdl-34605868

ABSTRACT

BACKGROUND: Data anonymization is an important building block for ensuring privacy and fosters the reuse of data. However, transforming the data in a way that preserves the privacy of subjects while maintaining a high degree of data quality is challenging and particularly difficult when processing complex datasets that contain a high number of attributes. In this article we present how we extended the open source software ARX to improve its support for high-dimensional, biomedical datasets. FINDINGS: For improving ARX's capability to find optimal transformations when processing high-dimensional data, we implement 2 novel search algorithms. The first is a greedy top-down approach and is oriented on a formally implemented bottom-up search. The second is based on a genetic algorithm. We evaluated the algorithms with different datasets, transformation methods, and privacy models. The novel algorithms mostly outperformed the previously implemented bottom-up search. In addition, we extended the GUI to provide a high degree of usability and performance when working with high-dimensional datasets. CONCLUSION: With our additions we have significantly enhanced ARX's ability to handle high-dimensional data in terms of processing performance as well as usability and thus can further facilitate data sharing.


Subject(s)
Data Anonymization , Privacy , Algorithms , Humans , Information Dissemination , Software
4.
Toxicol Sci ; 184(1): 67-82, 2021 10 27.
Article in English | MEDLINE | ID: mdl-34390580

ABSTRACT

Epidemiology studies link cigarillos and shisha tobacco (delivered through a hookah waterpipe) to increased risk for cardiopulmonary diseases. Here we performed a comparative chemical constituent analysis between 3 cigarettes, 3 cigarillos, and 8 shisha tobacco products. The potency for genotoxicity and oxidative stress of each product's generated total particulate matter (TPM) was also assessed using immortalized oral, lung, and cardiac cell lines to represent target tissues. Levels of the carcinogenic carbonyl formaldehyde were 32- to 95-fold greater, while acrolein was similar across the shisha aerosols generated by charcoal heating compared to cigarettes and cigarillos. Electric-mediated aerosol generation dramatically increased acrolein to levels exceeding those in cigarettes and cigarillos by up to 43-fold. Equivalent cytotoxic-mediated cell death and dose response for genotoxicity through induction of mutagenicity and DNA strand breaks was seen between cigarettes and cigarillos, while minimal to no effect was observed with shisha tobacco products. In contrast, increased potency of TPM from cigarillos compared to cigarettes for inducing oxidative stress via reactive oxygen radicals and lipid peroxidation across cell lines was evident, while positivity was seen for shisha tobacco products albeit at much lower levels. Together, these studies provide new insight into the potential harmful effects of cigarillos for causing tobacco-associated diseases. The high level of carbonyls in shisha products, that in turn is impacted by the heating mechanism, reside largely in the gas phase which will distribute throughout the respiratory tract and systemic circulation to likely increase genotoxic stress.


Subject(s)
Smoking Water Pipes , Tobacco Products , DNA Damage , Mutagens/toxicity , Smoke/adverse effects , Nicotiana/toxicity , Tobacco Products/toxicity
5.
Clin Epigenetics ; 13(1): 44, 2021 02 25.
Article in English | MEDLINE | ID: mdl-33632299

ABSTRACT

BACKGROUND: Trimethylation of lysine 27 and dimethylation of lysine 9 of histone-H3 catalyzed by the histone methyltransferases EZH2 and G9a impede gene transcription in cancer. Our human bronchial epithelial (HBEC) pre-malignancy model studied the role of these histone modifications in transformation. Tobacco carcinogen transformed HBEC lines were characterized for cytosine DNA methylation, transcriptome reprogramming, and the effect of inhibiting EZH2 and G9a on the transformed phenotype. The effects of targeting EZH2 and G9a on lung cancer prevention was assessed in the A/J mouse lung tumor model. RESULTS: Carcinogen exposure induced transformation and DNA methylation of 12-96 genes in the four HBEC transformed (T) lines that was perpetuated in malignant tumors. In contrast, 506 unmethylated genes showed reduced expression in one or more HBECTs with many becoming methylated in tumors. ChIP-on-chip for HBEC2T identified 327 and 143 genes enriched for H3K27me3 and H3K9me2. Treatment of HBEC2T and HBEC13T with DZNep, a lysine methyltransferase inhibitor depleted EZH2, reversed transformation, and induced transcriptional reprogramming. The EZH2 small molecule inhibitor EPZ6438 also affected transformation and expression in HBEC2T, while a G9a inhibitor, UNC0642 was ineffective. Genetic knock down of EZH2 dramatically reduced carcinogen-induced transformation of HBEC2. Only DZNep treatment prevented progression of hyperplasia to adenomas in the NNK mouse lung tumor model through reducing EZH2 and affecting the expression of genes regulating cell growth and invasion. CONCLUSION: These studies demonstrate a critical role for EZH2 catalyzed histone modifications for premalignancy and its potential as a target for chemoprevention of lung carcinogenesis.


Subject(s)
Chromatin Assembly and Disassembly/genetics , Enhancer of Zeste Homolog 2 Protein/genetics , Histone Code/drug effects , Neoplasms/prevention & control , Adenosine/analogs & derivatives , Adenosine/pharmacology , Adenosylhomocysteinase/antagonists & inhibitors , Animals , Benzamides/pharmacology , Biphenyl Compounds/pharmacology , Cell Proliferation/drug effects , CpG Islands , DNA Methylation/drug effects , Enhancer of Zeste Homolog 2 Protein/pharmacology , Enzyme Inhibitors/pharmacology , Epigenesis, Genetic/drug effects , Epithelial Cells/drug effects , Female , Histone Code/genetics , Histone Methyltransferases/antagonists & inhibitors , Histone Methyltransferases/metabolism , Histone-Lysine N-Methyltransferase/genetics , Histone-Lysine N-Methyltransferase/pharmacology , Histones/metabolism , Humans , Lung Neoplasms/chemically induced , Lung Neoplasms/pathology , Mice , Morpholines/pharmacology , Phenotype , Pyridones/pharmacology , Transcriptome/drug effects
6.
Toxicol Sci ; 179(2): 220-228, 2021 01 28.
Article in English | MEDLINE | ID: mdl-33226417

ABSTRACT

Electronic cigarettes are the most commonly used nicotine containing product among teenagers. The oral epithelium is the first site of exposure and our recent work revealed considerable diversity among e-liquids for composition and level of chemical constituents that impact nicotine deposition in a human oral-trachea cast and affect the formation of reactive carbonyls. Here, we evaluate the dose response for cytotoxicity and genotoxicity of e-cigarette-generated aerosols from 10 diverse flavored e-liquid products with and without nicotine compared with unflavored in 3 immortalized oral epithelial cell lines. Three e-liquids, Blue Pucker, Love Potion, and Jamestown caused ≥20% cell toxicity assessed by the neutral red uptake assay. Nine products induced significant levels of oxidative stress up to 2.4-fold quantified by the ROS-Glo assay in at least 1 cell line, with dose response seen for Love Potion with and without nicotine across all cell lines. Lipid peroxidation detected by the thiobarbituric acid reactive substances assay was less common among products; however, dose response increases up to 12-fold were seen for individual cell lines. Micronuclei formation indicative of genotoxicity was increased up to 5-fold for some products. Blue Pucker was the most genotoxic e-liquid, inducing micronuclei across all cell lines irrespective of nicotine status. A potency score derived from all assays identified Blue Pucker and Love Potion as the most hazardous e-liquids. These in vitro acute exposure studies provide new insight about the potential for some flavored vaping products to induce significant levels of oxidative stress and genotoxicity.


Subject(s)
Electronic Nicotine Delivery Systems , Adolescent , Aerosols/toxicity , Cell Line , DNA Damage , Epithelial Cells , Flavoring Agents/toxicity , Humans , Nicotine/toxicity
7.
Lung Cancer ; 146: 189-196, 2020 08.
Article in English | MEDLINE | ID: mdl-32559455

ABSTRACT

OBJECTIVES: Smoking is a common risk factor for chronic obstructive pulmonary disease (COPD) and lung cancer. Although COPD patients have higher risk of lung cancer compared to non-COPD smokers, the molecular links between these diseases are not well-defined. This study aims to identify genes that are downregulated by cigarette smoke and commonly repressed in COPD and lung cancer. MATERIALS AND METHODS: Primary human airway epithelial cells (HAEC) were exposed to cigarette-smoke-extract (CSE) for 10-weeks and significantly suppressed genes were identified by transcriptome array. Epigenetic abnormalities of these genes in lung adenocarcinoma (LUAD) from patients with or without COPD were determined using genome-wide and gene-specific assays and by in vitro treatment of cell lines with trichostatin-A or 5-aza-2-deoxycytidine. RESULTS: The ten most commonly downregulated genes following chronic CSE exposure of HAEC and show promoter hypermethylation in LUAD were selected. Among these, expression of CCNA1, SNCA, and ZNF549 was significantly reduced in lung tissues from COPD compared with non-COPD cases while expression of CCNA1 and SNCA was further downregulated in tumors with COPD. The promoter regions of all three genes were hypermethylated in LUAD but not normal or COPD lungs. The reduced expression and aberrant promoter hypermethylation of these genes in LUAD were independently validated using data from the Cancer Genome Atlas project. Importantly, SNCA and ZNF549 methylation detected in sputum DNA from LUAD (52% and 38%) cases were more prevalent compared to cancer-free smokers (26% and 15%), respectively (p < 0.02). CONCLUSIONS: Our data show that suppression of CCNA1, SNCA, and ZNF549 in lung cancer and COPD occurs with or without promoter hypermethylation, respectively. Detecting methylation of these and previously identified genes in sputum of cancer-free smokers may serve as non-invasive biomarkers for early detection of lung cancer among high risk smokers including COPD patients.


Subject(s)
Lung Neoplasms , Pulmonary Disease, Chronic Obstructive , Biomarkers , DNA Methylation , Epigenesis, Genetic , Humans , Lung , Lung Neoplasms/genetics , Pulmonary Disease, Chronic Obstructive/genetics , Smokers , Sputum
8.
Front Cell Infect Microbiol ; 10: 612360, 2020.
Article in English | MEDLINE | ID: mdl-33614527

ABSTRACT

Background: The role of lung epithelial cells in HIV-1-related lung comorbidities remains unclear, and the major hurdle in curing HIV is the persistence of latent HIV reservoirs in people living with HIV (PLWH). The advent of combined antiretroviral therapy has considerably increased the life span; however, the incidence of chronic lung diseases is significantly higher among PLWH. Lung epithelial cells orchestrate the respiratory immune responses and whether these cells are productively infected by HIV-1 is debatable. Methods: Normal human bronchial epithelial cells (NHBEs) grown on air-liquid interface were infected with X4-tropic HIV-1LAV and examined for latency using latency-reversing agents (LRAs). The role of CD4 and CXCR4 HIV coreceptors in NHBEs were tested, and DNA sequencing analysis was used to analyze the genomic integration of HIV proviral genes, Alu-HIVgag-pol, HIV-nef, and HIV-LTR. Lung epithelial sections from HIV-infected humans and SHIV-infected macaques were analyzed by FISH for HIV-gag-pol RNA and epithelial cell-specific immunostaining. Results and Discussion: NHBEs express CD4 and CXCR4 at higher levels than A549 cells. NHBEs are infected with HIV-1 basolaterally, but not apically, by X4-tropic HIV-1LAV in a CXCR4/CD4-dependent manner leading to HIV-p24 antigen production; however, NHBEs are induced to express CCR5 by IL-13 treatment. In the presence of cART, HIV-1 induces latency and integration of HIV provirus in the cellular DNA, which is rescued by the LRAs (endotoxin/vorinostat). Furthermore, lung epithelial cells from HIV-infected humans and SHIV-infected macaques contain HIV-specific RNA transcripts. Thus, lung epithelial cells are targeted by HIV-1 and could serve as potential HIV reservoirs that may contribute to the respiratory comorbidities in PLWH.


Subject(s)
HIV Infections , HIV-1 , Anti-Retroviral Agents , CD4-Positive T-Lymphocytes , Epithelial Cells , HIV Infections/drug therapy , HIV-1/genetics , Humans , Virus Latency
9.
Mol Carcinog ; 58(6): 1046-1055, 2019 06.
Article in English | MEDLINE | ID: mdl-30790354

ABSTRACT

Platinum anticancer agents are essential components in chemotherapeutic regimens for non-small-cell lung cancer (NSCLC) patients ineligible for targeted therapy. However, platinum-based regimens have reached a plateau of therapeutic efficacy; therefore, it is critical to implement novel approaches for improvement. The hexosamine biosynthesis pathway (HBP), which produces amino-sugar N-acetyl-glucosamine for protein glycosylation, is important for protein function and cell survival. Here we show a beneficial effect by the combination of cisplatin with HBP inhibition. Expression of glutamine:fructose-6-phosphate amidotransferase (GFAT), the rate-limiting enzyme of HBP, was increased in NSCLC cell lines and tissues. Pharmacological inhibition of GFAT activity or knockdown of GFATimpaired cell proliferation and exerted synergistic or additive cytotoxicity to the cells treated with cisplatin. Mechanistically, GFAT positively regulated the expression of binding immunoglobulin protein (BiP; also known as glucose-regulated protein 78, GRP78), an endoplasmic reticulum chaperone involved in unfolded protein response (UPR). Suppressing GFAT activity resulted in downregulation of BiP that activated inositol-requiring enzyme 1α, a sensor protein of UPR, and exacerbated cisplatin-induced cell apoptosis. These data identify GFAT-mediated HBP as a target for improving platinum-based chemotherapy for NSCLC.


Subject(s)
Carcinoma, Non-Small-Cell Lung/metabolism , Cisplatin/pharmacology , Diazooxonorleucine/pharmacology , Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing)/antagonists & inhibitors , Heat-Shock Proteins/metabolism , Lung Neoplasms/metabolism , A549 Cells , Carcinoma, Non-Small-Cell Lung/drug therapy , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Down-Regulation , Drug Synergism , Endoplasmic Reticulum Chaperone BiP , Gene Expression Regulation, Neoplastic/drug effects , Hexosamines/biosynthesis , Humans , Lung Neoplasms/drug therapy
10.
Cancer Res ; 79(8): 1758-1768, 2019 Apr 15.
Article in English | MEDLINE | ID: mdl-30622117

ABSTRACT

The role of transcriptional regulator ten-eleven translocation methylcytosine dioxygenease 1 (TET1) has not been well characterized in lung cancer. Here we show that TET1 is overexpressed in adenocarcinoma and squamous cell carcinomas. TET1 knockdown reduced cell growth in vitro and in vivo and induced transcriptome reprogramming independent of its demethylating activity to affect key cancer signaling pathways. Wild-type p53 bound the TET1 promoter to suppress transcription, while p53 transversion mutations were most strongly associated with high TET1 expression. Knockdown of TET1 in p53-mutant cell lines induced senescence through a program involving generalized genomic instability manifested by DNA single- and double-strand breaks and induction of p21 that was synergistic with cisplatin and doxorubicin. These data identify TET1 as an oncogene in lung cancer whose gain of function via loss of p53 may be exploited through targeted therapy-induced senescence. SIGNIFICANCE: These studies identify TET1 as an oncogene in lung cancer whose gain of function following loss of p53 may be exploited by targeted therapy-induced senescence.See related commentary by Kondo, p. 1751.


Subject(s)
Lung Neoplasms/genetics , Tumor Suppressor Protein p53/genetics , Cellular Senescence , Gene Expression Regulation, Neoplastic , Humans , Mixed Function Oxygenases , Proto-Oncogene Proteins
11.
Bioinformatics ; 35(3): 532-534, 2019 02 01.
Article in English | MEDLINE | ID: mdl-30032270

ABSTRACT

Summary: Associations of metabolomics data with phenotypic outcomes are expected to span functional modules, which are defined as sets of correlating metabolites that are coordinately regulated. Moreover, these associations occur at different scales, from entire pathways to only a few metabolites; an aspect that has not been addressed by previous methods. Here, we present MoDentify, a free R package to identify regulated modules in metabolomics networks at different layers of resolution. Importantly, MoDentify shows higher statistical power than classical association analysis. Moreover, the package offers direct interactive visualization of the results in Cytoscape. We present an application example using complex, multifluid metabolomics data. Due to its generic character, the method is widely applicable to other types of data. Availability and implementation: https://github.com/krumsieklab/MoDentify (vignette includes detailed workflow). Supplementary information: Supplementary data are available at Bioinformatics online.


Subject(s)
Computational Biology , Metabolomics , Software , Data Visualization , Phenotype
12.
Sch Psychol ; 34(2): 222-232, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30589313

ABSTRACT

Middle school is a risky period, marked by increased peer victimization, and the onset of several mental disorders, including suicidal thoughts and behaviors (STBs). Parental involvement is critical to students' well-being; however, few studies have examined the role of parental involvement among middle school students or its effect on their mental health. This study examined the effects of perceived parental involvement and victimization on adolescents' mental health difficulties (MHDs) and STBs. We also investigated whether these effects varied across demographic groups, and whether perceived parental involvement buffers the relationship between victimization and students' mental health outcomes. The sample consisted of 301,628 students (50.7% female) from 615 middle schools (Grades 6 to 8) in Georgia (United States). Hierarchical linear modeling showed that higher student-level perceived parental involvement was related to fewer MHDs (b = -0.20) and STBs (b = -0.10), and higher school-level perceived parental involvement was related to fewer STBs (b = -0.11). However, higher student-level (b = 0.25, 0.08) and school-level (b = 0.37, 0.10) traditional victimization were associated with more MHDs and STBs. Student-level perceived parental involvement was also more positively related to MHDs and STBs for 6th (b = 0.06, 0.04) and 7th graders (b = 0.03, 0.02) than for 8th graders, and it was more negatively related to MHDs (b = -0.24) and STBs (b = -0.13) for girls than for boys. Perceived parental involvement also moderated the relationships among traditional victimization, cyber victimization MHDs, and STBs. Implications are discussed relating to how schools can promote parental involvement and student mental health. (PsycINFO Database Record (c) 2019 APA, all rights reserved).


Subject(s)
Adolescent Behavior/psychology , Behavioral Symptoms/psychology , Bullying/psychology , Crime Victims/psychology , Parent-Child Relations , Parenting/psychology , Students/psychology , Suicide/psychology , Adolescent , Female , Humans , Male , Schools , Suicidal Ideation
13.
J Interprof Care ; 32(1): 111-114, 2018 Jan.
Article in English | MEDLINE | ID: mdl-28945164

ABSTRACT

Childhood obesity is a major public health concern with underpinnings at the individual, family, community and societal levels. The Transdisciplinary Childhood Obesity Prevention Graduate Certificate Program (TOP) is an innovative graduate-level certificate program developed to train professionals to understand and address obesity from multiple perspectives using an interprofessional education (IPE) approach. Currently, there is limited knowledge on what promotes or hinders learning in IPE approaches dealing with obesity prevention. The goal of this report is to address this gap by describing facilitators and barriers to learning in a graduate-level training program. Using a qualitative research design, semi-structured interviews were collected from 23 professional students, as part of a larger program evaluation project for TOP. Thematic analysis revealed the challenges and strengths of the program that relate specifically to: its interprofessional approach, its structure, and its activities. Interprofessional exchanges were reported to expand students' learning, but adequate interprofessional representation must be maintained, and the complexity of interprofessional collaborations must also be well-coordinated. Standardising the program structure and courses for consistency across professions, and clear communication are critical to program success. Findings add to the existing literature on what promotes effective learning in a professional obesity prevention program using an IPE approach.


Subject(s)
Education, Graduate/organization & administration , Health Occupations/education , Interdisciplinary Placement/organization & administration , Interprofessional Relations , Pediatric Obesity/prevention & control , Communication , Cooperative Behavior , Group Processes , Health Knowledge, Attitudes, Practice , Health Services Research/organization & administration , Humans , Interviews as Topic , Problem-Based Learning , Program Evaluation , Qualitative Research , Research Support as Topic/organization & administration , Workload/psychology
14.
Metabolomics ; 14(10): 128, 2018 09 20.
Article in English | MEDLINE | ID: mdl-30830398

ABSTRACT

BACKGROUND: Untargeted mass spectrometry (MS)-based metabolomics data often contain missing values that reduce statistical power and can introduce bias in biomedical studies. However, a systematic assessment of the various sources of missing values and strategies to handle these data has received little attention. Missing data can occur systematically, e.g. from run day-dependent effects due to limits of detection (LOD); or it can be random as, for instance, a consequence of sample preparation. METHODS: We investigated patterns of missing data in an MS-based metabolomics experiment of serum samples from the German KORA F4 cohort (n = 1750). We then evaluated 31 imputation methods in a simulation framework and biologically validated the results by applying all imputation approaches to real metabolomics data. We examined the ability of each method to reconstruct biochemical pathways from data-driven correlation networks, and the ability of the method to increase statistical power while preserving the strength of established metabolic quantitative trait loci. RESULTS: Run day-dependent LOD-based missing data accounts for most missing values in the metabolomics dataset. Although multiple imputation by chained equations performed well in many scenarios, it is computationally and statistically challenging. K-nearest neighbors (KNN) imputation on observations with variable pre-selection showed robust performance across all evaluation schemes and is computationally more tractable. CONCLUSION: Missing data in untargeted MS-based metabolomics data occur for various reasons. Based on our results, we recommend that KNN-based imputation is performed on observations with variable pre-selection since it showed robust results in all evaluation schemes.


Subject(s)
Mass Spectrometry , Metabolomics/methods , Chromatography, Liquid , Cohort Studies , Germany
15.
NPJ Syst Biol Appl ; 3: 28, 2017.
Article in English | MEDLINE | ID: mdl-28948040

ABSTRACT

The identification of phenotype-driven network modules in complex, multifluid metabolomics data poses a considerable challenge for statistical analysis and result interpretation. This is the case for phenotypes with only few associations ('sparse' effects), but, in particular, for phenotypes with a large number of metabolite associations ('dense' effects). Herein, we postulate that examining the data at different layers of resolution, from metabolites to pathways, will facilitate the interpretation of modules for both the sparse and the dense cases. We propose an approach for the phenotype-driven identification of modules on multifluid networks based on untargeted metabolomics data of plasma, urine, and saliva samples from the German Study of Health in Pomerania (SHIP-TREND) study. We generated a hierarchical, multifluid map of metabolism covering both metabolite and pathway associations using Gaussian graphical models. First, this map facilitates a fundamental understanding of metabolism within and across fluids for our study, and can serve as a valuable and downloadable resource. Second, based on this map, we then present an algorithm to identify regulated modules that associate with factors such as gender and insulin-like growth factor I (IGF-I) as examples of traits with dense and sparse associations, respectively. We found IGF-I to associate at the rather fine-grained metabolite level, while gender shows well-interpretable associations at pathway level. Our results confirm that a holistic and interpretable view of metabolic changes associated with a phenotype can only be obtained if different layers of metabolic resolution from multiple body fluids are considered.

16.
Sci Rep ; 7(1): 2235, 2017 05 22.
Article in English | MEDLINE | ID: mdl-28533544

ABSTRACT

The role of androgens in metabolism with respect to sex-specific disease associations is poorly understood. Therefore, we aimed to provide molecular signatures in plasma and urine of androgen action in a sex-specific manner using state-of-the-art metabolomics techniques. Our study population consisted of 430 men and 343 women, aged 20-80 years, who were recruited for the cross-sectional population-based Study of Health in Pomerania (SHIP-TREND), Germany. We used linear regression models to identify associations between testosterone, androstenedione and dehydroepiandrosterone-sulfate (DHEAS) as well as sex hormone-binding globulin and plasma or urine metabolites measured by mass spectrometry. The analyses revealed major sex-specific differences in androgen-associated metabolites, particularly for levels of urate, lipids and metabolic surrogates of lifestyle factors, like cotinine or piperine. In women, in particular in the postmenopausal state, androgens showed a greater impact on the metabolome than in men (especially DHEAS and lipids were highly related in women). We observed a novel association of androstenedione on the metabolism of biogenic amines and only a small sex-overlap of associations within steroid metabolism. The present study yields new insights in the interaction between androgens and metabolism, especially about their implication in female metabolism.


Subject(s)
Androgens/metabolism , Metabolome , Metabolomics , Sex Hormone-Binding Globulin/metabolism , Adult , Biomarkers , Female , Humans , Male , Metabolomics/methods , Middle Aged , Protein Binding , Public Health Surveillance , Risk Factors , Sex Factors
17.
Front Psychol ; 8: 2161, 2017.
Article in English | MEDLINE | ID: mdl-29326622

ABSTRACT

School adjustment and achievement are important indicators of adolescents' well-being; however, few studies have examined the risk and protective factors predicting students' school adjustment and achievement at the individual, familial, and cultural level. The present study examined the influences of individual and familial factors and cultural values on Chinese adolescents' school functioning (e.g., school adjustment and grades). It also tested whether cultural values moderated the relationship between parenting and adolescents' school functioning. Self-report data were collected from a stratified random sample of 2,864 adolescents (51.5% female, mean age = 15.52 years, grade 6th - 12th) from 55 classrooms, in 13 schools in Shanghai, China. Results showed that self-esteem (bse→adj = 0.05, SE = 0.01, p < 0.001; bse→grades = 0.08, SE = 0.02, p < 0.001), parent-adolescent conflict (bconflict→adj = -0.03, SE = 0.00, p < 0.001; bconflict→grades = -0.04, SE = 0.01, p < 0.001), and conformity to parental expectations (bconform→adj = -0.03, SE = 0.02, p < 0.05; bconform→grades = 0.10, SE = 0.04, p < 0.05) all had significant effects on both school adjustment and grades, respectively. More importantly, results showed that independent self-construal moderated the relationship between parental autonomy granting and adolescents' grades (bindepxautom = 0.06, SE = 0.02, p < 0.01). The findings suggest that cultural values may influence adolescents' appraisal of parental autonomy granting, which then impacts their school functioning.

18.
J Clin Endocrinol Metab ; 101(12): 4730-4742, 2016 12.
Article in English | MEDLINE | ID: mdl-27710242

ABSTRACT

OBJECTIVE: IGF-1 is known for its various physiological and severe pathophysiological effects on human metabolism; however, underlying molecular mechanisms still remain unsolved. To reveal possible molecular mechanisms mediating these effects, for the first time, we associated serum IGF-1 levels with multifluid untargeted metabolomics data. METHODS: Plasma/urine samples of 995 nondiabetic participants of the Study of Health in Pomerania were characterized by mass spectrometry. Sex-specific linear regression analyses were performed to assess the association of IGF-1 and IGF-1/IGF binding protein 3 ratio with metabolites. Additionally, the predictive ability of the plasma and urine metabolome for IGF-1 was assessed by orthogonal partial least squares analyses. RESULTS AND CONCLUSIONS: We revealed a multifaceted image of associated metabolites with large sex differences. Confirming previous reports, we detected relations between IGF-1 and steroid hormones or related intermediates. Furthermore, various associated metabolites were previously mentioned regarding IGF-1-associated diseases, eg, betaine and cortisol in cardiovascular disease and metabolic syndrome, lipid disorders, and diabetes, or have previously been found to associate with differentiation and proliferation or mitochondrial functionality, eg, phospholipids. bradykinin, fatty acid derivatives, and cortisol, which were inversely associated with IGF-1, might establish a link of IGF-1 with inflammation. For the first time, we showed an association between IGF-1 and pipecolate, a metabolite linked to amino acid metabolism. Our study demonstrates that IGF-1 action on metabolism is tractable, even in healthy subjects, and that the findings provide a solid basis for further experimental/clinical investigation, eg, searching for inflammatory or cardiovascular disease- or metabolic syndrome-associated biomarkers and therapeutic targets.


Subject(s)
Insulin-Like Growth Factor Binding Protein 3/metabolism , Insulin-Like Growth Factor I/metabolism , Metabolome/physiology , Metabolomics/methods , Registries , Adult , Aged , Female , Germany/epidemiology , Humans , Male , Middle Aged , Sex Factors , Young Adult
19.
Cancer Res ; 76(16): 4741-51, 2016 08 15.
Article in English | MEDLINE | ID: mdl-27302168

ABSTRACT

miRNA silencing by promoter hypermethylation may represent a mechanism by which lung cancer develops and progresses, but the miRNAs involved during malignant transformation are unknown. We previously established a model of premalignant lung cancer wherein we treated human bronchial epithelial cells (HBEC) with low doses of tobacco carcinogens. Here, we demonstrate that next-generation sequencing of carcinogen-transformed HBECs treated with the demethylating agent 5-aza-2'deoxycytidine revealed miR-196b and miR-34c-5p to be epigenetic targets. Bisulfite sequencing confirmed dense promoter hypermethylation indicative of silencing in multiple malignant cell lines and primary tumors. Chromatin immunoprecipitation studies further demonstrated an enrichment in repressive histone marks on the miR-196b promoter during HBEC transformation. Restoration of miR-196b expression by transfecting transformed HBECs with specific mimics led to cell-cycle arrest mediated in part through transcriptional regulation of the FOS oncogene, and miR-196b reexpression also significantly reduced the growth of tumor xenografts. Luciferase assays demonstrated that forced expression of miR-196b inhibited the FOS promoter and AP-1 reporter activity. Finally, a case-control study revealed that methylation of miR-196b in sputum was strongly associated with lung cancer (OR = 4.7, P < 0.001). Collectively, these studies highlight miR-196b as a tumor suppressor whose silencing early in lung carcinogenesis may provide a selective growth advantage to premalignant cells. Targeted delivery of miR-196b could therefore serve as a preventive or therapeutic strategy for the management of lung cancer. Cancer Res; 76(16); 4741-51. ©2016 AACR.


Subject(s)
Carcinoma, Non-Small-Cell Lung/genetics , Cell Transformation, Neoplastic/genetics , Epigenesis, Genetic/genetics , Lung Neoplasms/genetics , MicroRNAs/genetics , Animals , Blotting, Western , Carcinoma, Non-Small-Cell Lung/pathology , Case-Control Studies , Chromatin Immunoprecipitation , DNA Methylation , Female , Heterografts , High-Throughput Nucleotide Sequencing , Humans , Lung Neoplasms/pathology , Mice , Mice, Nude , Oligonucleotide Array Sequence Analysis , Polymerase Chain Reaction
20.
Int J Cancer ; 138(12): 2884-93, 2016 Jun 15.
Article in English | MEDLINE | ID: mdl-26860439

ABSTRACT

In DNA from prostate tumors, methylation patterns in gene promoter regions can be a biomarker for disease progression. It remains unclear whether methylation patterns in benign prostate tissue--prior to malignant transformation--may provide similar prognostic information. To determine whether early methylation events predict prostate cancer outcomes, we evaluated histologically benign prostate specimens from 353 men who eventually developed prostate cancer and received "definitive" treatment [radical prostatectomy (58%) or radiation therapy (42%)]. Cases were drawn from a large hospital-based cohort of men with benign prostate biopsy specimens collected between 1990 and 2002. Risk of disease progression associated with methylation was estimated using time-to-event analyses. Average follow-up was over 5 years; biochemical recurrence (BCR) occurred in 91 cases (26%). In White men, methylation of the APC gene was associated with increased risk of BCR, even after adjusting for standard clinical risk factors for prostate cancer progression (adjusted hazard ratio (aHR) = 2.26; 95%CI 1.23-4.16). APC methylation was most strongly associated with a significant increased risk of BCR in White men with low prostate specific antigen at cohort entry (HR = 3.66; 95%CI 1.51-8.85). In additional stratified analyses, we found that methylation of the RARB gene significantly increased risk of BCR in African American cases who demonstrated methylation of at least one of the other four genes under study (HR = 3.80; 95%CI 1.07-13.53). These findings may have implications in the early identification of aggressive prostate cancer as well as reducing unnecessary medical procedures and emotional distress for men who present with markers of indolent disease.


Subject(s)
Carcinogenesis/genetics , DNA Methylation , Prostatic Hyperplasia/genetics , Prostatic Neoplasms/genetics , Aged , Cohort Studies , Disease Progression , Gene Expression Regulation, Neoplastic , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Proportional Hazards Models , Prostate/pathology , Prostatic Hyperplasia/pathology , Risk , Sequence Analysis, DNA
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