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Publisher: Springer-Verlag (Total: 2352 journals)

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Showing 1 - 200 of 2352 Journals sorted alphabetically
3D Printing in Medicine     Open Access   (Followers: 2)
3D Research     Hybrid Journal   (Followers: 21, SJR: 0.222, CiteScore: 1)
4OR: A Quarterly J. of Operations Research     Hybrid Journal   (Followers: 10, SJR: 0.825, CiteScore: 1)
AAPS J.     Hybrid Journal   (Followers: 23, SJR: 1.118, CiteScore: 4)
AAPS PharmSciTech     Hybrid Journal   (Followers: 7, SJR: 0.752, CiteScore: 3)
Abdominal Imaging     Hybrid Journal   (Followers: 17, SJR: 0.866, CiteScore: 2)
Abhandlungen aus dem Mathematischen Seminar der Universitat Hamburg     Hybrid Journal   (Followers: 4, SJR: 0.439, CiteScore: 0)
Academic Psychiatry     Full-text available via subscription   (Followers: 27, SJR: 0.53, CiteScore: 1)
Academic Questions     Hybrid Journal   (Followers: 8, SJR: 0.106, CiteScore: 0)
Accreditation and Quality Assurance: J. for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 30, SJR: 0.316, CiteScore: 1)
Acoustical Physics     Hybrid Journal   (Followers: 11, SJR: 0.359, CiteScore: 1)
Acoustics Australia     Hybrid Journal   (SJR: 0.232, CiteScore: 1)
Acta Analytica     Hybrid Journal   (Followers: 7, SJR: 0.367, CiteScore: 0)
Acta Applicandae Mathematicae     Hybrid Journal   (Followers: 1, SJR: 0.675, CiteScore: 1)
Acta Biotheoretica     Hybrid Journal   (Followers: 4, SJR: 0.284, CiteScore: 1)
Acta Diabetologica     Hybrid Journal   (Followers: 18, SJR: 1.587, CiteScore: 3)
Acta Endoscopica     Hybrid Journal   (Followers: 1)
acta ethologica     Hybrid Journal   (Followers: 4, SJR: 0.769, CiteScore: 1)
Acta Geochimica     Hybrid Journal   (Followers: 7, SJR: 0.24, CiteScore: 1)
Acta Geodaetica et Geophysica     Hybrid Journal   (Followers: 3, SJR: 0.305, CiteScore: 1)
Acta Geophysica     Hybrid Journal   (Followers: 11, SJR: 0.312, CiteScore: 1)
Acta Geotechnica     Hybrid Journal   (Followers: 7, SJR: 1.588, CiteScore: 3)
Acta Informatica     Hybrid Journal   (Followers: 5, SJR: 0.517, CiteScore: 1)
Acta Mathematica     Hybrid Journal   (Followers: 13, SJR: 7.066, CiteScore: 3)
Acta Mathematica Hungarica     Hybrid Journal   (Followers: 2, SJR: 0.452, CiteScore: 1)
Acta Mathematica Sinica, English Series     Hybrid Journal   (Followers: 6, SJR: 0.379, CiteScore: 1)
Acta Mathematica Vietnamica     Hybrid Journal   (SJR: 0.27, CiteScore: 0)
Acta Mathematicae Applicatae Sinica, English Series     Hybrid Journal   (SJR: 0.208, CiteScore: 0)
Acta Mechanica     Hybrid Journal   (Followers: 21, SJR: 1.04, CiteScore: 2)
Acta Mechanica Sinica     Hybrid Journal   (Followers: 5, SJR: 0.607, CiteScore: 2)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 7, SJR: 0.576, CiteScore: 2)
Acta Meteorologica Sinica     Hybrid Journal   (Followers: 3, SJR: 0.638, CiteScore: 1)
Acta Neurochirurgica     Hybrid Journal   (Followers: 7, SJR: 0.822, CiteScore: 2)
Acta Neurologica Belgica     Hybrid Journal   (Followers: 2, SJR: 0.376, CiteScore: 1)
Acta Neuropathologica     Hybrid Journal   (Followers: 4, SJR: 7.589, CiteScore: 12)
Acta Oceanologica Sinica     Hybrid Journal   (Followers: 3, SJR: 0.334, CiteScore: 1)
Acta Physiologiae Plantarum     Hybrid Journal   (Followers: 3, SJR: 0.574, CiteScore: 2)
Acta Politica     Hybrid Journal   (Followers: 15, SJR: 0.605, CiteScore: 1)
Activitas Nervosa Superior     Hybrid Journal   (SJR: 0.147, CiteScore: 0)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 8, SJR: 0.103, CiteScore: 0)
ADHD Attention Deficit and Hyperactivity Disorders     Hybrid Journal   (Followers: 25, SJR: 0.72, CiteScore: 2)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 9)
Administration and Policy in Mental Health and Mental Health Services Research     Partially Free   (Followers: 18, SJR: 1.005, CiteScore: 2)
Adsorption     Hybrid Journal   (Followers: 5, SJR: 0.703, CiteScore: 2)
Advances in Applied Clifford Algebras     Hybrid Journal   (Followers: 4, SJR: 0.698, CiteScore: 1)
Advances in Atmospheric Sciences     Hybrid Journal   (Followers: 37, SJR: 0.956, CiteScore: 2)
Advances in Computational Mathematics     Hybrid Journal   (Followers: 19, SJR: 0.812, CiteScore: 1)
Advances in Contraception     Hybrid Journal   (Followers: 3)
Advances in Data Analysis and Classification     Hybrid Journal   (Followers: 57, SJR: 1.09, CiteScore: 1)
Advances in Gerontology     Partially Free   (Followers: 8, SJR: 0.144, CiteScore: 0)
Advances in Health Sciences Education     Hybrid Journal   (Followers: 32, SJR: 1.64, CiteScore: 2)
Advances in Manufacturing     Hybrid Journal   (Followers: 4, SJR: 0.475, CiteScore: 2)
Advances in Polymer Science     Hybrid Journal   (Followers: 45, SJR: 1.04, CiteScore: 3)
Advances in Therapy     Hybrid Journal   (Followers: 5, SJR: 1.075, CiteScore: 3)
Aegean Review of the Law of the Sea and Maritime Law     Hybrid Journal   (Followers: 7)
Aequationes Mathematicae     Hybrid Journal   (Followers: 2, SJR: 0.517, CiteScore: 1)
Aerobiologia     Hybrid Journal   (Followers: 3, SJR: 0.673, CiteScore: 2)
Aesthetic Plastic Surgery     Hybrid Journal   (Followers: 11, SJR: 0.825, CiteScore: 1)
African Archaeological Review     Hybrid Journal   (Followers: 21, SJR: 0.862, CiteScore: 1)
Afrika Matematika     Hybrid Journal   (Followers: 1, SJR: 0.235, CiteScore: 0)
AGE     Hybrid Journal   (Followers: 7)
Ageing Intl.     Hybrid Journal   (Followers: 7, SJR: 0.39, CiteScore: 1)
Aggiornamenti CIO     Hybrid Journal   (Followers: 1)
Aging Clinical and Experimental Research     Hybrid Journal   (Followers: 3, SJR: 0.67, CiteScore: 2)
Agricultural Research     Hybrid Journal   (Followers: 6, SJR: 0.276, CiteScore: 1)
Agriculture and Human Values     Hybrid Journal   (Followers: 14, SJR: 1.173, CiteScore: 3)
Agroforestry Systems     Hybrid Journal   (Followers: 20, SJR: 0.663, CiteScore: 1)
Agronomy for Sustainable Development     Hybrid Journal   (Followers: 13, SJR: 1.864, CiteScore: 6)
AI & Society     Hybrid Journal   (Followers: 9, SJR: 0.227, CiteScore: 1)
AIDS and Behavior     Hybrid Journal   (Followers: 14, SJR: 1.792, CiteScore: 3)
Air Quality, Atmosphere & Health     Hybrid Journal   (Followers: 4, SJR: 0.862, CiteScore: 3)
Akupunktur & Aurikulomedizin     Full-text available via subscription   (Followers: 1)
Algebra and Logic     Hybrid Journal   (Followers: 6, SJR: 0.531, CiteScore: 0)
Algebra Universalis     Hybrid Journal   (Followers: 2, SJR: 0.583, CiteScore: 1)
Algebras and Representation Theory     Hybrid Journal   (Followers: 1, SJR: 1.095, CiteScore: 1)
Algorithmica     Hybrid Journal   (Followers: 9, SJR: 0.56, CiteScore: 1)
Allergo J.     Full-text available via subscription   (Followers: 1, SJR: 0.234, CiteScore: 0)
Allergo J. Intl.     Hybrid Journal   (Followers: 2)
Alpine Botany     Hybrid Journal   (Followers: 5, SJR: 1.11, CiteScore: 3)
ALTEX : Alternatives to Animal Experimentation     Open Access   (Followers: 3)
AMBIO     Hybrid Journal   (Followers: 10, SJR: 1.569, CiteScore: 4)
American J. of Cardiovascular Drugs     Hybrid Journal   (Followers: 16, SJR: 0.951, CiteScore: 3)
American J. of Community Psychology     Hybrid Journal   (Followers: 29, SJR: 1.329, CiteScore: 2)
American J. of Criminal Justice     Hybrid Journal   (Followers: 9, SJR: 0.772, CiteScore: 1)
American J. of Cultural Sociology     Hybrid Journal   (Followers: 18, SJR: 0.46, CiteScore: 1)
American J. of Dance Therapy     Hybrid Journal   (Followers: 5, SJR: 0.181, CiteScore: 0)
American J. of Potato Research     Hybrid Journal   (Followers: 2, SJR: 0.611, CiteScore: 1)
American J. of Psychoanalysis     Hybrid Journal   (Followers: 21, SJR: 0.314, CiteScore: 0)
American Sociologist     Hybrid Journal   (Followers: 16, SJR: 0.35, CiteScore: 0)
Amino Acids     Hybrid Journal   (Followers: 8, SJR: 1.135, CiteScore: 3)
AMS Review     Partially Free   (Followers: 4)
Analog Integrated Circuits and Signal Processing     Hybrid Journal   (Followers: 7, SJR: 0.211, CiteScore: 1)
Analysis and Mathematical Physics     Hybrid Journal   (Followers: 5, SJR: 0.536, CiteScore: 1)
Analysis in Theory and Applications     Hybrid Journal   (Followers: 1)
Analysis of Verbal Behavior     Hybrid Journal   (Followers: 6)
Analytical and Bioanalytical Chemistry     Hybrid Journal   (Followers: 32, SJR: 0.978, CiteScore: 3)
Anatomical Science Intl.     Hybrid Journal   (Followers: 3, SJR: 0.367, CiteScore: 1)
Angewandte Schmerztherapie und Palliativmedizin     Hybrid Journal  
Angiogenesis     Hybrid Journal   (Followers: 3, SJR: 2.177, CiteScore: 5)
Animal Cognition     Hybrid Journal   (Followers: 20, SJR: 1.389, CiteScore: 3)
Annales françaises de médecine d'urgence     Hybrid Journal   (Followers: 1, SJR: 0.192, CiteScore: 0)
Annales Henri Poincaré     Hybrid Journal   (Followers: 3, SJR: 1.097, CiteScore: 2)
Annales mathématiques du Québec     Hybrid Journal   (Followers: 4, SJR: 0.438, CiteScore: 0)
Annali dell'Universita di Ferrara     Hybrid Journal   (SJR: 0.429, CiteScore: 0)
Annali di Matematica Pura ed Applicata     Hybrid Journal   (Followers: 1, SJR: 1.197, CiteScore: 1)
Annals of Biomedical Engineering     Hybrid Journal   (Followers: 17, SJR: 1.042, CiteScore: 3)
Annals of Combinatorics     Hybrid Journal   (Followers: 4, SJR: 0.932, CiteScore: 1)
Annals of Data Science     Hybrid Journal   (Followers: 12)
Annals of Dyslexia     Hybrid Journal   (Followers: 10, SJR: 0.85, CiteScore: 2)
Annals of Finance     Hybrid Journal   (Followers: 34, SJR: 0.579, CiteScore: 1)
Annals of Forest Science     Hybrid Journal   (Followers: 7, SJR: 0.986, CiteScore: 2)
Annals of Global Analysis and Geometry     Hybrid Journal   (Followers: 1, SJR: 1.228, CiteScore: 1)
Annals of Hematology     Hybrid Journal   (Followers: 15, SJR: 1.043, CiteScore: 2)
Annals of Mathematics and Artificial Intelligence     Hybrid Journal   (Followers: 12, SJR: 0.413, CiteScore: 1)
Annals of Microbiology     Hybrid Journal   (Followers: 11, SJR: 0.479, CiteScore: 2)
Annals of Nuclear Medicine     Hybrid Journal   (Followers: 5, SJR: 0.687, CiteScore: 2)
Annals of Operations Research     Hybrid Journal   (Followers: 10, SJR: 0.943, CiteScore: 2)
Annals of Ophthalmology     Hybrid Journal   (Followers: 12)
Annals of Regional Science     Hybrid Journal   (Followers: 8, SJR: 0.614, CiteScore: 1)
Annals of Software Engineering     Hybrid Journal   (Followers: 13)
Annals of Solid and Structural Mechanics     Hybrid Journal   (Followers: 9, SJR: 0.239, CiteScore: 1)
Annals of Surgical Oncology     Hybrid Journal   (Followers: 15, SJR: 1.986, CiteScore: 4)
Annals of Telecommunications     Hybrid Journal   (Followers: 9, SJR: 0.223, CiteScore: 1)
Annals of the Institute of Statistical Mathematics     Hybrid Journal   (Followers: 1, SJR: 1.495, CiteScore: 1)
Antonie van Leeuwenhoek     Hybrid Journal   (Followers: 5, SJR: 0.834, CiteScore: 2)
Apidologie     Hybrid Journal   (Followers: 4, SJR: 1.22, CiteScore: 3)
APOPTOSIS     Hybrid Journal   (Followers: 9, SJR: 1.424, CiteScore: 4)
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2, SJR: 0.294, CiteScore: 1)
Applications of Mathematics     Hybrid Journal   (Followers: 2, SJR: 0.602, CiteScore: 1)
Applied Biochemistry and Biotechnology     Hybrid Journal   (Followers: 44, SJR: 0.571, CiteScore: 2)
Applied Biochemistry and Microbiology     Hybrid Journal   (Followers: 18, SJR: 0.21, CiteScore: 1)
Applied Categorical Structures     Hybrid Journal   (Followers: 4, SJR: 0.49, CiteScore: 0)
Applied Composite Materials     Hybrid Journal   (Followers: 49, SJR: 0.58, CiteScore: 2)
Applied Entomology and Zoology     Partially Free   (Followers: 6, SJR: 0.422, CiteScore: 1)
Applied Geomatics     Hybrid Journal   (Followers: 3, SJR: 0.733, CiteScore: 3)
Applied Geophysics     Hybrid Journal   (Followers: 9, SJR: 0.488, CiteScore: 1)
Applied Intelligence     Hybrid Journal   (Followers: 13, SJR: 0.6, CiteScore: 2)
Applied Magnetic Resonance     Hybrid Journal   (Followers: 4, SJR: 0.319, CiteScore: 1)
Applied Mathematics & Optimization     Hybrid Journal   (Followers: 8, SJR: 0.886, CiteScore: 1)
Applied Mathematics - A J. of Chinese Universities     Hybrid Journal   (SJR: 0.17, CiteScore: 0)
Applied Mathematics and Mechanics     Hybrid Journal   (Followers: 5, SJR: 0.461, CiteScore: 1)
Applied Microbiology and Biotechnology     Hybrid Journal   (Followers: 66, SJR: 1.182, CiteScore: 4)
Applied Physics A     Hybrid Journal   (Followers: 10, SJR: 0.481, CiteScore: 2)
Applied Physics B: Lasers and Optics     Hybrid Journal   (Followers: 24, SJR: 0.74, CiteScore: 2)
Applied Psychophysiology and Biofeedback     Hybrid Journal   (Followers: 8, SJR: 0.519, CiteScore: 2)
Applied Research in Quality of Life     Hybrid Journal   (Followers: 12, SJR: 0.316, CiteScore: 1)
Applied Solar Energy     Hybrid Journal   (Followers: 22, SJR: 0.225, CiteScore: 0)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 7, SJR: 0.542, CiteScore: 1)
Aquaculture Intl.     Hybrid Journal   (Followers: 26, SJR: 0.591, CiteScore: 2)
Aquarium Sciences and Conservation     Hybrid Journal   (Followers: 2)
Aquatic Ecology     Hybrid Journal   (Followers: 37, SJR: 0.656, CiteScore: 2)
Aquatic Geochemistry     Hybrid Journal   (Followers: 4, SJR: 0.591, CiteScore: 1)
Aquatic Sciences     Hybrid Journal   (Followers: 14, SJR: 1.109, CiteScore: 3)
Arabian J. for Science and Engineering     Hybrid Journal   (Followers: 5, SJR: 0.303, CiteScore: 1)
Arabian J. of Geosciences     Hybrid Journal   (Followers: 2, SJR: 0.319, CiteScore: 1)
Archaeological and Anthropological Sciences     Hybrid Journal   (Followers: 21, SJR: 1.052, CiteScore: 2)
Archaeologies     Hybrid Journal   (Followers: 12, SJR: 0.224, CiteScore: 0)
Archiv der Mathematik     Hybrid Journal   (Followers: 1, SJR: 0.725, CiteScore: 1)
Archival Science     Hybrid Journal   (Followers: 66, SJR: 0.745, CiteScore: 2)
Archive for History of Exact Sciences     Hybrid Journal   (Followers: 7, SJR: 0.186, CiteScore: 1)
Archive for Mathematical Logic     Hybrid Journal   (Followers: 3, SJR: 0.909, CiteScore: 1)
Archive for Rational Mechanics and Analysis     Hybrid Journal   (SJR: 3.93, CiteScore: 3)
Archive of Applied Mechanics     Hybrid Journal   (Followers: 6, SJR: 0.79, CiteScore: 2)
Archives and Museum Informatics     Hybrid Journal   (Followers: 157, SJR: 0.101, CiteScore: 0)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 6, SJR: 1.41, CiteScore: 5)
Archives of Dermatological Research     Hybrid Journal   (Followers: 7, SJR: 1.006, CiteScore: 2)
Archives of Environmental Contamination and Toxicology     Hybrid Journal   (Followers: 14, SJR: 0.773, CiteScore: 2)
Archives of Gynecology and Obstetrics     Hybrid Journal   (Followers: 17, SJR: 0.956, CiteScore: 2)
Archives of Microbiology     Hybrid Journal   (Followers: 9, SJR: 0.644, CiteScore: 2)
Archives of Orthopaedic and Trauma Surgery     Hybrid Journal   (Followers: 9, SJR: 1.146, CiteScore: 2)
Archives of Osteoporosis     Hybrid Journal   (Followers: 2, SJR: 0.71, CiteScore: 2)
Archives of Sexual Behavior     Hybrid Journal   (Followers: 10, SJR: 1.493, CiteScore: 3)
Archives of Toxicology     Hybrid Journal   (Followers: 17, SJR: 1.541, CiteScore: 5)
Archives of Virology     Hybrid Journal   (Followers: 5, SJR: 0.973, CiteScore: 2)
Archives of Women's Mental Health     Hybrid Journal   (Followers: 16, SJR: 1.274, CiteScore: 3)
Archivio di Ortopedia e Reumatologia     Hybrid Journal  
Archivum Immunologiae et Therapiae Experimentalis     Hybrid Journal   (Followers: 2, SJR: 0.946, CiteScore: 3)
ArgoSpine News & J.     Hybrid Journal  
Argumentation     Hybrid Journal   (Followers: 6, SJR: 0.349, CiteScore: 1)
Arid Ecosystems     Hybrid Journal   (Followers: 2, SJR: 0.2, CiteScore: 0)
Arkiv för Matematik     Hybrid Journal   (Followers: 2, SJR: 0.766, CiteScore: 1)
Arnold Mathematical J.     Hybrid Journal   (Followers: 1, SJR: 0.355, CiteScore: 0)
Arthropod-Plant Interactions     Hybrid Journal   (Followers: 2, SJR: 0.839, CiteScore: 2)
Arthroskopie     Hybrid Journal   (Followers: 1, SJR: 0.131, CiteScore: 0)
Artificial Intelligence and Law     Hybrid Journal   (Followers: 11, SJR: 0.937, CiteScore: 2)
Artificial Intelligence Review     Hybrid Journal   (Followers: 18, SJR: 0.833, CiteScore: 4)
Artificial Life and Robotics     Hybrid Journal   (Followers: 9, SJR: 0.226, CiteScore: 0)
Asia Europe J.     Hybrid Journal   (Followers: 5, SJR: 0.504, CiteScore: 1)
Asia Pacific Education Review     Hybrid Journal   (Followers: 13, SJR: 0.479, CiteScore: 1)
Asia Pacific J. of Management     Hybrid Journal   (Followers: 16, SJR: 1.185, CiteScore: 2)
Asia-Pacific Education Researcher     Hybrid Journal   (Followers: 13, SJR: 0.353, CiteScore: 1)
Asia-Pacific Financial Markets     Hybrid Journal   (Followers: 3, SJR: 0.187, CiteScore: 0)
Asia-Pacific J. of Atmospheric Sciences     Hybrid Journal   (Followers: 19, SJR: 0.855, CiteScore: 1)
Asian Business & Management     Hybrid Journal   (Followers: 9, SJR: 0.378, CiteScore: 1)
Asian J. of Business Ethics     Hybrid Journal   (Followers: 10)
Asian J. of Criminology     Hybrid Journal   (Followers: 6, SJR: 0.543, CiteScore: 1)
AStA Advances in Statistical Analysis     Hybrid Journal   (Followers: 4, SJR: 0.548, CiteScore: 1)
AStA Wirtschafts- und Sozialstatistisches Archiv     Hybrid Journal   (Followers: 5, SJR: 0.183, CiteScore: 0)
ästhetische dermatologie & kosmetologie     Full-text available via subscription  
Astronomy and Astrophysics Review     Hybrid Journal   (Followers: 22, SJR: 3.385, CiteScore: 5)

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Similar Journals
Journal Cover
Archives of Toxicology
Journal Prestige (SJR): 1.541
Citation Impact (citeScore): 5
Number of Followers: 17  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1432-0738 - ISSN (Online) 0340-5761
Published by Springer-Verlag Homepage  [2352 journals]
  • The role of fuel type and combustion phase on the toxicity of biomass
           smoke following inhalation exposure in mice
    • Abstract: The characteristics of wildland fire smoke exposures which initiate or exacerbate cardiopulmonary conditions are unclear. We previously reported that, on a mass basis, lung toxicity associated with particulate matter (PM) from flaming smoke aspirated into mouse lungs is greater than smoldering PM. In this study, we developed a computer-controlled inhalation system which can precisely control complex biomass smoke emissions from different combustion conditions. This system was used to examine the toxicity of inhaled biomass smoke from peat, eucalyptus, and oak fuels generated under smoldering and flaming phases with emissions set to the same approximate concentration of carbon monoxide (CO) for each exposure (60–110 ppm), resulting in PM levels of ~ 4 mg/m3 for flaming and ~ 40 mg/m3 for smoldering conditions. Mice were exposed by inhalation 1 h/day for 2 days, and assessed for lung toxicity at 4 and 24 h after the final exposure. Peat (flaming and smoldering) and eucalyptus (smoldering) smoke elicited significant inflammation (neutrophil influx) in mouse lungs at 4 h with the peat (flaming) smoke causing even greater lung inflammation at 24-h post-exposure. A significant alteration in ventilatory timing was also observed in mice exposed to the peat (flaming) and eucalyptus (flaming and smoldering) smoke immediately after each day of exposure. No responses were seen for exposures to similar concentrations of flaming or smoldering oak smoke. The lung toxicity potencies (neutrophil influx per PM mass) agreed well between the inhalation and previously reported aspiration studies, demonstrating that although flaming smoke contains much less PM mass than smoldering smoke, it is more toxic on a mass basis than smoldering smoke exposure, and that fuel type is also a controlling factor.
      PubDate: 2019-04-20
       
  • A high-cholesterol diet promotes steatohepatitis and liver tumorigenesis
           in HCV core gene transgenic mice
    • Abstract: Previous epidemiological studies have suggested a link between high-cholesterol intake and liver disease progression, including hepatocellular carcinoma (HCC). However, the precise mechanism of hepatotoxicity and hepatocarcinogenesis caused by excessive cholesterol consumption remains unclear. We aimed to investigate the impact of dietary cholesterol using hepatitis C virus core gene transgenic (HCVcpTg) mice, which spontaneously developed HCC with age. Male HCVcpTg mice were treated for 15 months with either a control diet or an isocaloric diet containing 1.5% cholesterol, and liver phenotypes and tumor-associated signaling pathways were evaluated. The high-cholesterol diet-fed HCVcpTg mice exhibited a significantly higher incidence of liver tumors compared with the control diet mice (100% vs. 41%, P < 0.001). The diet induced steatohepatitis with pericellular fibrosis and evoked higher mRNA expression of pro-inflammatory and pro-fibrotic mediators along with enhanced hepatocyte proliferation and greater oxidative and endoplasmic reticulum stress in the liver. Moreover, long-term consumption of cholesterol-rich diet activated nuclear factor-kappa B (NF-κB) and p62/sequestosome 1 (Sqstm1)-nuclear factor erythroid 2 (NRF2) axis, enhanced fibrogenesis, and consequently accelerated hepatic tumorigenesis. In conclusion, these results demonstrate that a high-cholesterol diet facilitates liver tumorigenesis by inducing steatohepatitis, promoting hepatocyte division, and up-regulating cellular stress and pro-inflammatory NF-κB and detoxifying p62/Sqstm1-NRF2 signals. Therefore, high dietary cholesterol should be avoided in HCV-infected patients to prevent development of steatohepatitis, liver fibrosis, and HCC.
      PubDate: 2019-04-19
       
  • A toll-like receptor 9 agonist sensitizes mice to mitochondrial
           dysfunction-induced hepatic apoptosis via the Fas/FasL pathway
    • Abstract: Early hepatocyte death occurs in most liver injury cases and triggers liver inflammation, which in combination with other risk factors leads to the development of liver disease. However, the pathogenesis of early phase hepatocyte death remains poorly understood. Here, C57BL/6J mice were treated with the hepatotoxic drug flucloxacillin (FLUX) and the toll-like receptor 9 agonist CpG oligodeoxynucleotide (ODN) to reproduce the early phase of drug-induced hepatotoxicity and investigate its pathogenesis. C57BL/6J mice were treated with FLUX (100 mg/kg, gavage) alone or in combination with ODN (40 μg/mouse, intraperitoneally). Plasma alanine aminotransferase (ALT) level was measured as a marker of hepatotoxicity. FLUX or ODN alone was insufficient to induce ALT elevation, whereas combination treatment with FLUX and ODN increased ALT levels 24 h after FLUX treatment and upregulated Fas ligand in natural killer T (NKT) cells and Fas in hepatocytes. FLUX induced mitochondrial permeability transition (MPT), and pretreatment with ODN sensitized mitochondria to FLUX-induced MPT. The increase in ALT levels induced by ODN and FLUX co-treatment was suppressed in Fas ligand (gld/gld)-deficient mice and in mice deficient in a component of MPT pore opening (cyclophilin D-knockout mice). These results suggested that ODN activated the Fas/Fas ligand-mediated pathway in NKT cells and hepatocytes, which may predispose to FLUX-induced mitochondrial dysfunction and lead to early phase hepatocyte apoptosis. Taken together, these findings elucidate a potentially novel mechanism underlying drug-induced early phase hepatocyte death related to the Fas/Fas ligand death receptor pathway and mitochondrial dysfunction.
      PubDate: 2019-04-16
       
  • In vitro models to study insulin and glucocorticoids modulation of
           trimethyltin (TMT)-induced neuroinflammation and neurodegeneration, and in
           vivo validation in db/db mice
    • Abstract: Brain susceptibility to a neurotoxic insult may be increased in a compromised health status, such as metabolic syndrome. Both metabolic syndrome and exposure to trimethyltin (TMT) are known to promote neurodegeneration. In combination the two factors may elicit additive or compensatory/regulatory mechanisms. Combined effects of TMT exposure (0.5–1 μM) and mimicked metabolic syndrome—through modulation of insulin and glucocorticoid (GC) levels—were investigated in three models: tridimensional rat brain cell cultures for neuron-glia effects; murine microglial cell line BV-2 for a mechanistic analysis of microglial reactivity; and db/db mice as an in vivo model of metabolic syndrome. In 3D cultures, low insulin condition significantly exacerbated TMT’s effect on GABAergic neurons and promoted TMT-induced neuroinflammation, with increased expression of cytokines and of the regulator of intracellular GC activity, 11β-hydroxysteroid dehydrogenase 1 (11β-Hsd1). Microglial reactivity increased upon TMT exposure in medium combining low insulin and high GC. These results were corroborated in BV-2 microglial cells where lack of insulin exacerbated the TMT-induced increase in 11β-Hsd1 expression. Furthermore, TMT-induced microglial reactivity seems to depend on mineralocorticoid receptor activation. In diabetic BKS db mice, a discrete exacerbation of TMT neurotoxic effects on GABAergic neurons was observed, together with an increase of interleukin-6 (IL-6) and of basal 11β-Hsd1 expression as compared to controls. These results suggest only minor additive effects of the two brain insults, neurotoxicant TMT exposure and metabolic syndrome conditions, where 11β-Hsd1 appears to play a key role in the regulation of neuroinflammation and of its protective or neurodegenerative consequences.
      PubDate: 2019-04-16
       
  • Will worker DNELs derived under the European REACH regulation extend the
           landscape of occupational exposure guidance values'
    • Abstract: Derived no-effect levels for workers (wDNELs) under the European REACH legislation have many aspects in common with occupational exposure limits (OELs). In an attempt to examine under which circumstances wDNELs might be used as exposure guidance outside their intended application, we compared derivation methods, coverage of substances and numerical values of wDNELs against two regulatory OEL lists (European Commission and Sweden) and three sets of recommendations (European SCOEL, German MAK and US ACGIH). Finally, we looked closer at wDNELs where SCOEL concluded that data were insufficient to derive an OEL. Major differences between wDNELs and OELs include regulatory background, intended use, actors involved, substance selection criteria, transparency and procedure of derivation, and operationalisation in terms of risk management measures. As of summer 2018, approximately five times more substances were covered by wDNELs than by the five sets of OELs examined herein. Meanwhile, many occupationally relevant pollutants were not covered by wDNELs, e.g. one-third of Swedish OELs lack corresponding wDNELs. We also note that wDNELs and OELs for the same substance may vary considerably, up to several orders of magnitude. In conclusion, with extensive substance coverage, wDNELs extend the landscape beyond the OELs. That said, important limitations are (1) that many air pollutants relevant for workers’ health are not covered by REACH, and (2) concerns for inconsistencies in the derivation of wDNELs and in their level of protection. In particular, that route-to-route extrapolation is a common practice that may be grossly misleading when the effect of concern is local, e.g. sensitisation.
      PubDate: 2019-04-16
       
  • Overcoming acquired resistance of gefitinib in lung cancer cells without
           T790M by AZD9291 or Twist1 knockdown in vitro and in vivo
    • Abstract: The T790M mutation is recognized as a typical mechanism of acquired resistance to first generation of epithermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) such as gefitinib in non-small cell lung cancer (NSCLC) patients who are commonly treated by third generation of EGFR-TKI AZD9291 (osimertinib). However, the therapeutic strategy for overcoming acquired resistance to EGFR-TKIs in NSCLC patients without T790M remains to be definitively determined. In the present study, gefitinib-resistant H1650 (H1650GR) or AZD9291-resistant H1975 (H1975AR) was generated by exposing NSCLC cell line H1650 or H1975 to progressively increased concentrations of gefitinib or AZD9291 over 11 months. The cytotoxic effects of gefitinib or AZD9291 in vitro were evaluated via the half maximal inhibitory concentrations (IC50s) determined by the MTT assay. IC50 of gefitinib in H1650GR (50.0 ± 3.0 µM) significantly increased compared with H1650 (31.0 ± 1.0 µM) (p < 0.05). Similarly, the IC50 of AZD9291 in H1975AR (10.3 ± 0.9 µM) significantly increased compared with H1975 (5.5 ± 0.6 µM) (p < 0.05). However, IC50 of AZD9291 on H1650GR (8.5 ± 0.5 µM) did not increase compared with H1650 (9.7 ± 0.7 µM). On the other hand, IC50 of AZD9291 on gefitinib-resistant A549 (A549GR established in our previous study) (12.7 ± 0.8 µM) was significantly increased compared with A549 (7.0 ± 1.0 µM) (p < 0.05). AZD9291 induced caspase 3/7 activation in A549, H1650, and H1650GR, but not in A549GR. Western blot analyses showed that p-Akt played a key role in determining the sensitivities of A549, A549GR, H1650, and H1650GR to gefitinib or AZD9291. Additionally, increased expression of Twist1 was observed in all cells with acquired EGFR-TKI resistance and knockdown of Twist1 by shRNA was found to significantly enhance the sensitivity of A549GR to gefitinib or AZD9291 via reversing epithelial–mesenchymal transition and downregulating p-Akt, but not of H1975AR to AZD9291. The enhanced cytotoxic effect of AZD9291 on A549GR by Twist1 knockdown in vitro was further validated by in vivo studies which showed that Twist1 knockdown could lead to significantly delayed tumor growth of A549GR xenograft with increased sensitivity to AZD9291 treatment in nude mice without any observed side toxic effects. In summary, our study demonstrated that the mechanisms of acquired resistance in different NSCLC cell lines treated by even the same EGFR-TKI might be quite different, which provide a rationale for adopting different therapeutic strategies for those NSCLC patients with acquired EGFR-TKI resistance based on different status of heterogeneous mutations.
      PubDate: 2019-04-16
       
  • Understanding the skin sensitization capacity of ascaridole: a combined
           study of chemical reactivity and activation of the innate immune system
           (dendritic cells) in the epidermal environment
    • Abstract: To improve the prediction of the possible allergenicity of chemicals in contact with the skin, investigations of upstream events are required to better understand the molecular mechanisms involved in the initiation of allergic reactions. Ascaridole, one of the compounds responsible for skin sensitization to aged tea tree oil, degrades into intermediates that evolve via different mechanisms involving radical species. We aimed at broadening the knowledge about the contribution of radical intermediates derived from ascaridole to the skin sensitization process by assessing the reactivity profile towards amino acids, identifying whether free radicals are formed in a reconstructed human epidermis (RHE) model and their biological properties to activate the immune system, namely dendritic cells in their natural context of human HaCaT keratinocytes and RHE. Electron paramagnetic resonance combined to spin-trapping in EpiSkin™ RHE confirmed the formation of C-radicals in the epidermal tissue from 10 mM ascaridole concentration, while reactivity studies toward amino acids showed electrophilic intermediates issued from radical rearrangements of ascaridole as the main reactive species. Activation of THP-1 cells, as surrogate for dendritic cells, that were cocultured with HaCaT was significantly upregulated after treatment with low micromolar concentrations based on cell surface expression of the co-stimulatory molecule CD86 and the adhesion molecule CD54. Placing THP-1 cells underneath the RHE allowed us to monitor which of the concentrations that produce radical(s) and/or protein antigens in the epidermal skin environment promote the activation of dendritic cells. We detected no significant upregulation of CD86/CD54 after topical RHE application of concentrations up to 30 mM ascaridole (t = 24 h) but clear upregulation after 60 mM.
      PubDate: 2019-04-16
       
  • Pregnane X receptor mediates steatotic effects of propiconazole and
           tebuconazole in human liver cell lines
    • Abstract: Triazoles are commonly used fungicides which show liver toxicity in rodent studies. While hepatocellular hypertrophy is the most prominent finding, some triazoles have also been reported to cause hepatocellular steatosis. The aim of our study was to elucidate molecular mechanisms of triazole-mediated steatosis. Therefore, we used the two triazoles propiconazole (Pi) and tebuconazole (Te) as test compounds in in vitro assays using the human hepatocarcinoma cell lines HepG2 and HepaRG. Triglyceride accumulation was measured using the Adipored assay and by a gas-chromatographic method. Reporter gene analyses were used to assess the ability of Pi and Te to activate nuclear receptors, which are described as the molecular initiators in the adverse outcome pathway (AOP) for liver steatosis. The expression of steatosis-associated genes was investigated by RT-PCR. Mechanistic analyses of triazole-mediated steatosis were performed using HepaRG subclones that are deficient in different nuclear receptors. Pi and Te both interacted with the constitutive androstane receptor (CAR), the peroxisome proliferator-activated receptor alpha (PPARα), and the pregnane X receptor (PXR). Both compounds induced expression of steatosis-related genes and cellular triglyceride accumulation. The knockout of PXR in HepaRG cells, but not the CAR knockout, abolished triazole-induced triglyceride accumulation, thus underlining the crucial role of PXR in hepatic steatosis resulting from exposure to these fungicides. In conclusion, our findings provide new insight into the molecular mechanisms of steatosis induction by triazole fungicides and identify PXR as a critical mediator of this process.
      PubDate: 2019-04-15
       
  • 1-Methoxy-3-indolylmethyl DNA adducts in six tissues, and blood protein
           adducts, in mice under pak choi diet: time course and persistence
    • Abstract: We previously showed that purified 1-methoxy-3-indolylmethyl (1-MIM) glucosinolate, a secondary plant metabolite in Brassica species, is mutagenic in various in vitro systems and forms DNA and protein adducts in mouse models. In the present study, we administered 1-MIM glucosinolate in a natural matrix to mice, by feeding a diet containing pak choi powder and extract. Groups of animals were killed after 1, 2, 4 and 8 days of pak choi diet, directly or, in the case of the 8-day treatment, after 0, 8 and 16 days of recovery with pak choi-free diet. DNA adducts [N2-(1-MIM)-dG, N6-(1-MIM)-dA] in six tissues, as well as protein adducts [τN-(1-MIM)-His] in serum albumin (SA) and hemoglobin (Hb) were determined using UPLC–MS/MS with isotopically labeled internal standards. None of the samples from the 12 control animals under standard diet contained any 1-MIM adducts. All groups receiving pak choi diet showed DNA adducts in all six tissues (exception: lung of mice treated for a single day) as well as SA and Hb adducts. During the feeding period, all adduct levels continuously increased until day 8 (in the jejunum until day 4). During the 14-day recovery period, N2-(1-MIM)-dG in liver, kidney, lung, jejunum, cecum and colon decreased to 52, 41, 59, 11, 7 and 2%, respectively, of the peak level. The time course of N6-(1-MIM)-dA was similar. Immunohistochemical analyses indicated that cell turnover is a major mechanism of DNA adduct elimination in the intestine. In the same recovery period, protein adducts decreased more rapidly in SA than in Hb, to 0.7 and 37%, respectively, of the peak level, consistent with the differential turnover of these proteins. In conclusion, the pak choi diet lead to the formation of high levels of adducts in mice. Cell and protein turnover was a major mechanism of adduct elimination, at least in gut and blood.
      PubDate: 2019-04-15
       
  • Toxicity of C 60 fullerene–cisplatin nanocomplex against Lewis lung
           carcinoma cells
    • Abstract: Cisplatin (Cis-Pt) is the cytotoxic agent widely used against tumors of various origin, but its therapeutic efficiency is substantially limited by a non-selective effect and high toxicity. Conjugation of Cis-Pt with nanocarriers is thought to be one option to enable drug targeting. The aim of this study was to estimate toxic effects of the nanocomplex formed by noncovalent interaction of C60 fullerene with Cis-Pt against Lewis lung carcinoma (LLC) cells in comparison with free drug. Scanning tunneling microscopy showed that the minimum size of C60–Cis-Pt nanoparticles in aqueous colloid solution was 1.1 nm whereas that of C60 fullerene was 0.72 nm, thus confirming formation of the nanocomplex. The cytotoxic effect of C60–Cis-Pt nanocomplex against LLC cells was shown to be higher with IC50 values 3.3 and 4.5 times lower at 48 h and 72 h, respectively, as compared to the free drug. 12.5 µM Cis-Pt had no effect on LLC cell viability and morphology while C60–Cis-Pt nanocomplex in Cis-Pt-equivalent concentration substantially decreased the cell viability, impaired their shape and adhesion, inhibited migration and induced accumulation in proapoptotic subG1 phase. Apoptosis induced by the C60–Cis-Pt nanocomplex was confirmed by caspase 3/7 activation and externalization of phosphatidylserine on the outer surface of LLC cells with the double Annexin V-FITC/PI staining. We assume that C60 fullerene as a component of the C60–Cis-Pt nanocomplex promoted Cis-Pt entry and intracellular accumulation thus contributing to intensification of the drug’s toxic effect against lung cancer cells.
      PubDate: 2019-04-15
       
  • Toxicological assessment of magnesium oxide nanoparticles in HT29
           intestinal cells
    • Abstract: Nanoparticles (NPs) are increasingly used in different consumer-related areas, for instance in food packaging or as additives, because of their enormous potential. Magnesium oxide (MgO) is an EU-approved food additive (E number 530). It is commonly used as a drying agent for powdered foods, for colour retention or as a food supplement. There are no consistent results regarding the effects of oral MgO NP uptake. Consequently, the aim of this study was to examine the effects of MgO NPs in the HT29 intestinal cell line. MgO NP concentrations ranged from 0.001 to 100 μg/ml and incubation times were up to 24 h. The cytotoxic and genotoxic potential were investigated. Apoptotic processes and cell cycle changes were analysed by flow cytometry. Finally, oxidative stress was examined. Transmission electron microscopy indicated that there was no cellular uptake. MgO NPs had no cytotoxic or genotoxic effects in HT29 cells and they did not induce apoptotic processes, cell cycle changes or oxidative stress.
      PubDate: 2019-04-15
       
  • The LRP6 functional mutation rs2302685 contributes to individual
           susceptibility to alcoholic liver injury related to the
           Wnt/β-catenin-TCF1-CYP2E1 signaling pathway
    • Abstract: Low-density lipoprotein receptor-related protein 6 (LRP6) is an important coreceptor in the Wnt/β-catenin upstream signaling pathway. Rs2302685 is a common functional mutation of LRP6 that has been previously associated with reduced alcoholic liver injury among alcoholic liver disease (ALD) patients, and the present research was designed to study the underlying mechanisms of that finding. A total of 107 ALD patients and 138 non-ALD patients were recruited from hospitalized alcoholics in China. Their venous blood samples were collected for DNA extraction and genotyped using Sequenom MassARRAY. We found that the rs2302685 mutation, which impaired the function of LRP6, was present in higher frequency among alcoholics with ALD than those without ALD. We also conducted a mouse model experiment in which LRP6(+/−) knockdown mice and LRP6(+/+) wild-type mice received daily intragastric doses of ethanol (2.4 g/kg) as well as a larger dose of ethanol (4 g/kg) every 7 days for 28 days. The mouse blood and liver specimens were subsequently collected for laboratory analysis, and cell experiments were performed to compare the inhibition, activation, over-expression, and siRNA of LRP6 in the treatment versus the control HL7702 cells. Expression of the targeted molecules was detected by real-time PCR or western blot analysis. Stably transfected cells with pRL3-CYP2E1 vector were used to further study the underlying mechanisms. The total bile acid (TBA), direct bilirubin, total bilirubin (TBIL), aspartate aminotransferase (AST), mitochondrial aspartate aminotransferase, and AST/ALT values were significantly lower in carriers of the rs2302685 mutation than in the wild-type patients, by 63.4, 60.6, 82.1, 44.8, 45.7, and 21.4%, respectively. Compared to the LRP6(+/+) wild-type mice, the LRP6(+/−) knockdown mice had lower ALT, TBIL, TBA, and ALB/GLO values, as well reduced liver tissue damage, in accordance with their reduced expressions of LRP6, β-catenin, and CYP2E1. In HL7702 cells exposed to ethanol, AST, ALT, lipid accumulation, and ROS generation decreased in cells that were treated with LRP6 inhibitors or siRNA but increased in cells treated with LRP6 activators or over-expressed LRP6. TCF1 was the transcriptional factor most likely to connect the LRP6-Wnt/β-catenin signaling pathway to the regulation of CYP2E1. We concluded that the LRP6 functional mutation rs2302685 contributes to individual differences in susceptibility to alcoholic liver injury related to the Wnt/β-catenin-TCF1-CYP2E1 signaling pathway.
      PubDate: 2019-04-11
       
  • Quinone–thioether metabolites of hydroquinone play a dual role in
           promoting a vicious cycle of ROS generation: in vitro and in silico
           insights
    • Abstract: Humans are exposed to hydroquinone (HQ) via diet, smoking, occupation, and even via inhalation of polluted air. Given its preferential distribution in kidney and liver, the impact of biotransformation on the nephrotoxicity and hepatotoxicity of HQ was evaluated. Indeed, HQ and its metabolites, benzoquinone, and quinone–thioethers (50, 100, 200, and 400 μM) all induced ROS-dependent cell death in both HK-2, a human kidney proximal epithelial cell line, and THLE-2, a human liver epithelial cell line, in a concentration-dependent manner. For a deeper insight into the biological mechanism of ROS stimulation, the bioinformatics database was reviewed. Intriguingly, 163 proteins were currently reported to form co-crystal complex with benzoquinone analogs, a large proportion of which are closely related to ROS generation. After a thorough assessment of the interaction affinity and binding energy, three key mitochondrial proteins that are particularly involved in electric transport, namely, cytochrome BC1, succinate dehydrogenase, and sulfide:quinone oxidoreductase, were highlighted for further verification. Their binding affinity and the action pattern were explored and validated by molecular docking and molecular dynamics simulations. Remarkably, quinone–thioether metabolites of HQ afforded high affinity to the above proteins that purportedly cause a surge in the generation of ROS. Therefore, HQ can be further converted into quinone–thioethers, which on one hand can function as substrates for redox cycling, and on the other hand may afford high affinity with key proteins evolved in mitochondrial electron transport system, leading to a vicious cycle of ROS generation. The combined data provide a prospective insight into the mechanisms of ROS motivation, expanding HQ-mediated toxicology profiles.
      PubDate: 2019-04-11
       
  • Mechanisms and in vitro models of drug-induced cholestasis
    • Abstract: Cholestasis underlies one of the major manifestations of drug-induced liver injury. Drug-induced cholestatic liver toxicity is a complex process, as it can be triggered by a variety of factors that induce 2 types of biological responses, namely a deteriorative response, caused by bile acid accumulation, and an adaptive response, aimed at removing the accumulated bile acids. Several key events in both types of responses have been characterized in the past few years. In parallel, many efforts have focused on the development and further optimization of experimental cell culture models to predict the occurrence of drug-induced cholestatic liver toxicity in vivo. In this paper, a state-of-the-art overview of mechanisms and in vitro models of drug-induced cholestatic liver injury is provided.
      PubDate: 2019-04-10
       
  • Adverse outcome pathway for aminoglycoside ototoxicity in drug-resistant
           tuberculosis treatment
    • Abstract: Individuals treated for multidrug-resistant tuberculosis (MDR-TB) with aminoglycosides (AGs) in resource-limited settings often experience permanent hearing loss. However, AG ototoxicity has never been conceptually integrated or causally linked to MDR-TB patients’ pre-treatment health condition. We sought to develop a framework that examines the relationships between pre-treatment conditions and AG-induced hearing loss among MDR-TB-infected individuals in sub-Saharan Africa. The adverse outcome pathway (AOP) approach was used to develop a framework linking key events (KEs) within a biological pathway that results in adverse outcomes (AO), which are associated with chemical perturbation of a molecular initiating event (MIE). This AOP describes pathways initiating from AG accumulation in hair cells, sound transducers of the inner ear immediately after AG administration. After administration, the drug catalyzes cellular oxidative stress due to overproduction of reactive oxygen species. Since oxidative stress inhibits mitochondrial protein synthesis, hair cells undergo apoptotic cell death, resulting in irreversible hearing loss (AO). We identified the following pre-treatment conditions that worsen the causal linkage between MIE and AO: HIV, malnutrition, aging, noise, smoking, and alcohol use. The KEs are: (1) nephrotoxicity, pre-existing hearing loss, and hypoalbuminemia that catalyzes AG accumulation; (2) immunodeficiency and antioxidant deficiency that trigger oxidative stress pathways; and (3) co-administration of mitochondrial toxic drugs that hinder mitochondrial protein synthesis, causing apoptosis. This AOP clearly warrants the development of personalized interventions for patients undergoing MDR-TB treatment. Such interventions (i.e., choosing less ototoxic drugs, scheduling frequent monitoring, modifying nutritional status, avoiding poly-pharmacy) will be required to limit the burden of AG ototoxicity.
      PubDate: 2019-04-08
       
  • Report from the BfR expert hearing on practicability of hormonal
           measurements: recommendations for experimental design of toxicological
           studies with integrated hormonal end points
    • Abstract: This publication summarizes discussions that were held during an international expert hearing organized by the German Federal Institute for Risk Assessment (BfR) in Berlin, Germany, in October 2017. The expert hearing was dedicated to providing practical guidance for the measurement of circulating hormones in regulatory toxicology studies. Adequate measurements of circulating hormones have become more important given the regulatory requirement to assess the potential for endocrine disrupting properties for all substances covered by the plant protection products and biocidal products regulations in the European Union (EU). The main focus was the hypothalamus–pituitary–thyroid axis (HPT) and the hypothalamus–pituitary–gonadal axis (HPG). Insulin, insulin-like growth factor 1 (IGF-1), parathyroid hormone (PTH) and vitamins A and D were also discussed. During the hearing, the experts agreed on specific recommendations for design, conduct and evaluation of acceptability of studies measuring thyroid hormones, thyroid stimulating hormone and reproductive hormones as well as provided some recommendations for insulin and IGF-1. Experts concluded that hormonal measurements as part of the test guidelines (TGs) of the Organisation for Economic Co-operation and Development (OECD) were necessary on the condition that quality criteria to guarantee reliability and reproducibility of measurements are adhered to. Inclusion of the female reproductive hormones in OECD TGs was not recommended unless the design of the study was modified to appropriately measure hormone concentrations. The current report aims at promoting standardization of the experimental designs of hormonal assays to allow their integration in OECD TGs and highlights research needs for better identification of endocrine disruptors using hormone measurements.
      PubDate: 2019-03-30
       
  • Adductomics: a promising tool for the verification of chemical warfare
           agents’ exposures in biological samples
    • Abstract: Humans are constantly exposed to a wide range of reactive and toxic chemicals from the different sources in everyday life. Identification of the exposed chemical helps in the detection and understanding the exposure associated adverse health effects. Covalent adducts of proteins and DNA formed after xenobiotics exposure may serve as readily measurable indicators of these exposures. Measuring the exposed chemicals with focus on adducts resulting from the nucleophilic interactions with blood proteins is useful in the development of diagnostic markers. Particularly, the most abundant proteins such as albumin and hemoglobin acts as dominant scavengers for many reactive chemicals in blood and can serve as excellent diagnostic candidates to determine the type of chemical exposure. This review focuses on the potential application of an adductomics approach for the screening of bimolecular adducts of chemical warfare agents (CWAs). Recent incidents of CWAs use in Syria, Malaysia, and the UK illustrate the continuing threat of chemical warfare agents in the modern world. Detection of CWAs and their metabolites in blood or in other body fluids of victims depends on immediate access to victims. Concentrations of intact CWAs in body fluids of surviving victims may decline rapidly within a few days. Certain CWAs, particularly nerve agents and vesicants, form covalent bonds with certain amino acids to form CWA-protein adducts. Proteins that are abundant in the blood, including albumin and hemoglobin, may carry these adducts longer after the original exposure. We searched MEDLINE and ISI Web of Science databases using the key terms “adductomics” “adducts of CWAs,” “CWAs adducts detection in the biological samples,” “protein adducts of CWAs,” alone and in combination with the keywords “detection” “intoxication” “exposure” “adverse effects” and “toxicity.” We also included non-peer-reviewed sources such as text books, relevant newspaper reports, and applicable Internet resources. We screened bibliographies of identified articles for additional relevant studies including non-indexed reports. These searches produced 1931 citations of which only relevant and nonduplicate citations were considered for this review. The analysis of biomedical samples has several purposes including detecting and identifying the type of chemical agent exposed, understanding the biological mechanism, assists in giving adequate treatment, determining the cause of death and providing evidence in a court of justice for forensic investigations. Rapid advances in the mass spectrometry to acquire high-quality data with greater resolution enabled the analysis of protein and DNA adducts of xenobiotics including CWAs and place the rapidly advancing ‘adductomics’ next to the other “-omics” technologies. Adductomics can serve as a powerful bioanalytical tool for the verification of CWAs exposure. This review mostly describes the protein adducts for nerve agents and vesicants, outlines the procedures for measuring adducts, and suggests the evolving (or future) use of adducts in the detection and verification of CWAs.
      PubDate: 2019-03-28
       
  • Nephrotoxicity instead of immunotoxicity of OTA is induced through
           DNMT1-dependent activation of JAK2/STAT3 signaling pathway by targeting
           SOCS3
    • Abstract: Ochratoxin A (OTA) is reported to induce nephrotoxicity and immunotoxicity in animals and humans. However, the underlying mechanism and the effects of OTA on DNA damage have not been reported until now. The present study aims to investigate OTA-induced cytotoxicity and DNA damage and the underlying mechanism in PK15 cells and PAMs. The results showed that OTA at 2.0–8.0 µg/mL for 24 h induced cytotoxicity and DNA damage in PK15 cells and PAMs as demonstrated by decreasing cell viabilities and mRNA levels of DNA repair genes (OGG1, NEIL1 and NEIL3), increasing LDH release, Annexin V staining cells, apoptotic nuclei and the accumulation of γ-H2AX foci. OTA at 2.0–8.0 µg/mL increased DNMT1 and SOCS3 mRNA expressions about 2–4 fold in PK15 cells or 1.3–2 fold in PAMs. OTA at 2.0–8.0 µg/mL increased DNMT1, SOCS3, JAK2 and STAT3 protein expressions in PK15 cells or PAMs. DNMT inhibitor (5-Aza-2-dc), promoted SOCS3 expression, inhibited JAK2 and STAT3 expression, alleviated cytotoxicity, apoptosis and DNA damage induced by OTA at 4.0 µg/mL in PK15 cells. While, in PAMs, 5-Aza-2-dc had no effects on SOCS3 expression induced by OTA at 4.0 µg/mL, but inhibited JAK2 and STAT3 expression, and alleviated cytotoxicity, apoptosis and DNA damage induced by OTA. JAK inhibitor (AG490) or STAT3-siRNA alleviated OTA-induced cytotoxicity and DNA damage in PK15 cells or PAMs. Taken together, nephrotoxicity instead of immunotoxicity of OTA is induced by targeting SOCS3 through DNMT1-mediated JAK2/STAT3 signaling pathway. These results provide a scientific and new explanation of the underlying mechanism of OTA-induced nephrotoxicity and immunotoxicity.
      PubDate: 2019-03-28
       
  • Integrated in vitro models for hepatic safety and metabolism: evaluation
           of a human Liver-Chip and liver spheroid
    • Abstract: Drug-induced liver injury remains a frequent reason for drug withdrawal. Accordingly, more predictive and translational models are required to assess human hepatotoxicity risk. This study presents a comprehensive evaluation of two promising models to assess mechanistic hepatotoxicity, microengineered Organ-Chips and 3D hepatic spheroids, which have enhanced liver phenotype, metabolic activity and stability in culture not attainable with conventional 2D models. Sensitivity of the models to two hepatotoxins, acetaminophen (APAP) and fialuridine (FIAU), was assessed across a range of cytotoxicity biomarkers (ATP, albumin, miR-122, α-GST) as well as their metabolic functionality by quantifying APAP, FIAU and CYP probe substrate metabolites. APAP and FIAU produced dose- and time-dependent increases in miR-122 and α-GST release as well as decreases in albumin secretion in both Liver-Chips and hepatic spheroids. Metabolic turnover of CYP probe substrates, APAP and FIAU, was maintained over the 10-day exposure period at concentrations where no cytotoxicity was detected and APAP turnover decreased at concentrations where cytotoxicity was detected. With APAP, the most sensitive biomarkers were albumin in the Liver-Chips (EC50 5.6 mM, day 1) and miR-122 and ATP in the liver spheroids (14-fold and EC50 2.9 mM, respectively, day 3). With FIAU, the most sensitive biomarkers were albumin in the Liver-Chip (EC50 126 µM) and miR-122 (15-fold) in the liver spheroids, both on day 7. In conclusion, both models exhibited integrated toxicity and metabolism, and broadly similar sensitivity to the hepatotoxicants at relevant clinical concentrations, demonstrating the utility of these models for improved hepatotoxicity risk assessment.
      PubDate: 2019-03-26
       
  • Ochratoxin A causes mitochondrial dysfunction, apoptotic and autophagic
           cell death and also induces mitochondrial biogenesis in human gastric
           epithelium cells
    • Abstract: Ochratoxin A (OTA) is a common natural contaminant found in human and animal food worldwide. Our previous work has shown that OTA can cause oxidative DNA damage, G2 arrest and malignant transformation of human gastric epithelium (GES-1) cells. Mitochondria are considered to be target for the action of many cytotoxic agents. However, the role of mitochondria in the cytotoxicity of OTA remains unknown. The aim of this study is to explore the putative role of mitochondria on OTA cytotoxicity by analyzing mitochondrial changes in GES-1 cells. The results showed that OTA treatment (5, 10, 20 µM) for different times caused increases in the production of reactive oxygen species, and induced mitochondrial damage, shown by loss of mitochondrial membrane potential (ΔΨM), and decrease in cellular ATP concentration. Subsequently, the mitochondrial apoptotic pathway was activated, presented by increase of apoptotic rate and activation of apoptotic proteins. Autophagic cell death was also triggered, demonstrated by the conversion of light chain 3B (LC3B)-I to LC3B-II and elevated levels of green fluorescent protein-LC3 (GFP-LC3) puncta. Moreover, Parkin-dependent mitophagy was also activated presented by the colocalization of MitoTracker with LysoTracker or GFP-LC3 puncta. The inhibition of autophagy and mitophagy by inhibitors or siRNA attenuated the toxic effect of OTA on cell growth. Interestingly, OTA treatment also enhanced mitochondrial biogenesis confirmed by activation of AMPK/PGC-1α/TFAM pathway and promoted cell survival. Collectively, the effects of OTA on mitochondria of GES-1 cells are complex. OTA could cause mitochondrial function disturbance, apoptotic and autophagic cell death and also induce mitochondrial biogenesis.
      PubDate: 2019-03-22
       
 
 
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