WorldWideScience

Sample records for chemical skin sensitizers

  1. Predicting chemically-induced skin reactions. Part II: QSAR models of skin permeability and the relationships between skin permeability and skin sensitization

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Vinicius M. [Laboratory of Molecular Modeling and Design, Faculty of Pharmacy, Federal University of Goiás, Goiânia, GO 74605-220 (Brazil); Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Muratov, Eugene [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Laboratory of Theoretical Chemistry, A.V. Bogatsky Physical–Chemical Institute NAS of Ukraine, Odessa 65080 (Ukraine); Fourches, Denis [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Strickland, Judy; Kleinstreuer, Nicole [ILS/Contractor supporting the NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM), P.O. Box 13501, Research Triangle Park, NC 27709 (United States); Andrade, Carolina H. [Laboratory of Molecular Modeling and Design, Faculty of Pharmacy, Federal University of Goiás, Goiânia, GO 74605-220 (Brazil); Tropsha, Alexander, E-mail: alex_tropsha@unc.edu [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States)

    2015-04-15

    Skin permeability is widely considered to be mechanistically implicated in chemically-induced skin sensitization. Although many chemicals have been identified as skin sensitizers, there have been very few reports analyzing the relationships between molecular structure and skin permeability of sensitizers and non-sensitizers. The goals of this study were to: (i) compile, curate, and integrate the largest publicly available dataset of chemicals studied for their skin permeability; (ii) develop and rigorously validate QSAR models to predict skin permeability; and (iii) explore the complex relationships between skin sensitization and skin permeability. Based on the largest publicly available dataset compiled in this study, we found no overall correlation between skin permeability and skin sensitization. In addition, cross-species correlation coefficient between human and rodent permeability data was found to be as low as R{sup 2} = 0.44. Human skin permeability models based on the random forest method have been developed and validated using OECD-compliant QSAR modeling workflow. Their external accuracy was high (Q{sup 2}{sub ext} = 0.73 for 63% of external compounds inside the applicability domain). The extended analysis using both experimentally-measured and QSAR-imputed data still confirmed the absence of any overall concordance between skin permeability and skin sensitization. This observation suggests that chemical modifications that affect skin permeability should not be presumed a priori to modulate the sensitization potential of chemicals. The models reported herein as well as those developed in the companion paper on skin sensitization suggest that it may be possible to rationally design compounds with the desired high skin permeability but low sensitization potential. - Highlights: • It was compiled the largest publicly-available skin permeability dataset. • Predictive QSAR models were developed for skin permeability. • No concordance between skin

  2. Predicting chemically-induced skin reactions. Part I: QSAR models of skin sensitization and their application to identify potentially hazardous compounds

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Vinicius M. [Laboratory of Molecular Modeling and Design, Faculty of Pharmacy, Federal University of Goiás, Goiânia, GO 74605-220 (Brazil); Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Muratov, Eugene [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Laboratory of Theoretical Chemistry, A.V. Bogatsky Physical-Chemical Institute NAS of Ukraine, Odessa 65080 (Ukraine); Fourches, Denis [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States); Strickland, Judy; Kleinstreuer, Nicole [ILS/Contractor Supporting the NTP Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM), P.O. Box 13501, Research Triangle Park, NC 27709 (United States); Andrade, Carolina H. [Laboratory of Molecular Modeling and Design, Faculty of Pharmacy, Federal University of Goiás, Goiânia, GO 74605-220 (Brazil); Tropsha, Alexander, E-mail: alex_tropsha@unc.edu [Laboratory for Molecular Modeling, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27599 (United States)

    2015-04-15

    Repetitive exposure to a chemical agent can induce an immune reaction in inherently susceptible individuals that leads to skin sensitization. Although many chemicals have been reported as skin sensitizers, there have been very few rigorously validated QSAR models with defined applicability domains (AD) that were developed using a large group of chemically diverse compounds. In this study, we have aimed to compile, curate, and integrate the largest publicly available dataset related to chemically-induced skin sensitization, use this data to generate rigorously validated and QSAR models for skin sensitization, and employ these models as a virtual screening tool for identifying putative sensitizers among environmental chemicals. We followed best practices for model building and validation implemented with our predictive QSAR workflow using Random Forest modeling technique in combination with SiRMS and Dragon descriptors. The Correct Classification Rate (CCR) for QSAR models discriminating sensitizers from non-sensitizers was 71–88% when evaluated on several external validation sets, within a broad AD, with positive (for sensitizers) and negative (for non-sensitizers) predicted rates of 85% and 79% respectively. When compared to the skin sensitization module included in the OECD QSAR Toolbox as well as to the skin sensitization model in publicly available VEGA software, our models showed a significantly higher prediction accuracy for the same sets of external compounds as evaluated by Positive Predicted Rate, Negative Predicted Rate, and CCR. These models were applied to identify putative chemical hazards in the Scorecard database of possible skin or sense organ toxicants as primary candidates for experimental validation. - Highlights: • It was compiled the largest publicly-available skin sensitization dataset. • Predictive QSAR models were developed for skin sensitization. • Developed models have higher prediction accuracy than OECD QSAR Toolbox. • Putative

  3. Evaluation of in silico tools to predict the skin sensitization potential of chemicals.

    Science.gov (United States)

    Verheyen, G R; Braeken, E; Van Deun, K; Van Miert, S

    2017-01-01

    Public domain and commercial in silico tools were compared for their performance in predicting the skin sensitization potential of chemicals. The packages were either statistical based (Vega, CASE Ultra) or rule based (OECD Toolbox, Toxtree, Derek Nexus). In practice, several of these in silico tools are used in gap filling and read-across, but here their use was limited to make predictions based on presence/absence of structural features associated to sensitization. The top 400 ranking substances of the ATSDR 2011 Priority List of Hazardous Substances were selected as a starting point. Experimental information was identified for 160 chemically diverse substances (82 positive and 78 negative). The prediction for skin sensitization potential was compared with the experimental data. Rule-based tools perform slightly better, with accuracies ranging from 0.6 (OECD Toolbox) to 0.78 (Derek Nexus), compared with statistical tools that had accuracies ranging from 0.48 (Vega) to 0.73 (CASE Ultra - LLNA weak model). Combining models increased the performance, with positive and negative predictive values up to 80% and 84%, respectively. However, the number of substances that were predicted positive or negative for skin sensitization in both models was low. Adding more substances to the dataset will increase the confidence in the conclusions reached. The insights obtained in this evaluation are incorporated in a web database www.asopus.weebly.com that provides a potential end user context for the scope and performance of different in silico tools with respect to a common dataset of curated skin sensitization data.

  4. Chemical reactivity and skin sensitization potential for benzaldehydes: can Schiff base formation explain everything?

    Science.gov (United States)

    Natsch, Andreas; Gfeller, Hans; Haupt, Tina; Brunner, Gerhard

    2012-10-15

    Skin sensitizers chemically modify skin proteins rendering them immunogenic. Sensitizing chemicals have been divided into applicability domains according to their suspected reaction mechanism. The widely accepted Schiff base applicability domain covers aldehydes and ketones, and detailed structure-activity-modeling for this chemical group was presented. While Schiff base formation is the obvious reaction pathway for these chemicals, the in silico work was followed up by limited experimental work. It remains unclear whether hydrolytically labile Schiff bases can form sufficiently stable epitopes to trigger an immune response in the living organism with an excess of water being present. Here, we performed experimental studies on benzaldehydes of highly differing skin sensitization potential. Schiff base formation toward butylamine was evaluated in acetonitrile, and a detailed SAR study is presented. o-Hydroxybenzaldehydes such as salicylaldehyde and the oakmoss allergens atranol and chloratranol have a high propensity to form Schiff bases. The reactivity is highly reduced in p-hydroxy benzaldehydes such as the nonsensitizing vanillin with an intermediate reactivity for p-alkyl and p-methoxy-benzaldehydes. The work was followed up under more physiological conditions in the peptide reactivity assay with a lysine-containing heptapeptide. Under these conditions, Schiff base formation was only observable for the strong sensitizers atranol and chloratranol and for salicylaldehyde. Trapping experiments with NaBH₃CN showed that Schiff base formation occurred under these conditions also for some less sensitizing aldehydes, but the reaction is not favored in the absence of in situ reduction. Surprisingly, the Schiff bases of some weaker sensitizers apparently may react further to form stable peptide adducts. These were identified as the amides between the lysine residues and the corresponding acids. Adduct formation was paralleled by oxidative deamination of the parent

  5. The critical review of methodologies and approaches to assess the inherent skin sensitization potential (skin allergies) of chemicals. Part I

    DEFF Research Database (Denmark)

    Thyssen, Jacob P; Giménez-Arnau, Elena; Lepoittevin, Jean-Pierre;

    2012-01-01

    To critically review currently available methods, or methods under development (in vivo, in vitro, in silico, etc.) used in the evaluation of skin sensitization potential and their applicability in the derivation of quantitative 'safety thresholds'.......To critically review currently available methods, or methods under development (in vivo, in vitro, in silico, etc.) used in the evaluation of skin sensitization potential and their applicability in the derivation of quantitative 'safety thresholds'....

  6. Assessment of Chemical Skin-Sensitizing Potency by an In Vitro Assay Based on Human Dendritic Cells

    OpenAIRE

    Lambrechts, Nathalie; Vanheel, Hanne; Nelissen, Inge; Witters, Hilda; VAN DEN HEUVEL Rosette; Van Tendeloo, Viggo; Schoeters, Greet; HOOYBERGHS, Jef

    2010-01-01

    The skin-sensitizing potential of chemicals is an important concern for public health and thus a significant end point in the hazard identification process. To determine skin-sensitizing capacity, large research efforts focus on the development of assays, which do not require animals. As such, an in vitro test has previously been developed based on the differential expression of CREM and CCR2 transcripts in CD34(+) progenitor-derived dendritic cells (CD34-DC), which allows to classify chemica...

  7. Pathophysiological Study of Sensitive Skin.

    Science.gov (United States)

    Buhé, Virginie; Vié, Katell; Guéré, Christelle; Natalizio, Audrey; Lhéritier, Céline; Le Gall-Ianotto, Christelle; Huet, Flavien; Talagas, Matthieu; Lebonvallet, Nicolas; Marcorelles, Pascale; Carré, Jean-Luc; Misery, Laurent

    2016-03-01

    Sensitive skin is a clinical syndrome characterized by the occurrence of unpleasant sensations, such as pruritus, burning or pain, in response to various factors, including skincare products, water, cold, heat, or other physical and/or chemical factors. Although these symptoms suggest inflammation and the activation of peripheral innervation, the pathophysiogeny of sensitive skin remains unknown. We systematically analysed cutaneous biopsies from 50 healthy women with non-sensitive or sensitive skin and demonstrated that the intraepidermal nerve fibre density, especially that of peptidergic C-fibres, was lower in the sensitive skin group. These fibres are involved in pain, itching and temperature perception, and their degeneration may promote allodynia and similar symptoms. These results suggest that the pathophysiology of skin sensitivity resembles that of neuropathic pruritus within the context of small fibre neuropathy, and that environmental factors may alter skin innervation.

  8. Hypnosis as sole anaesthesia for skin tumour removal in a patient with multiple chemical sensitivity.

    Science.gov (United States)

    Facco, E; Pasquali, S; Zanette, G; Casiglia, E

    2013-09-01

    A female patient with multiple chemical sensitivity and previous anaphylactoid reactions to local anaesthetics was admitted for removal of a thigh skin tumour under hypnosis as sole anaesthesia. The hypnotic protocol included hypnotic focused analgesia and a pre-operative pain threshold test. After inducing hypnosis, a wide excision was performed, preserving the deep fascia, and the tumour was removed; the patient's heart rate and blood pressure did not increase during the procedure. When the patient was de-hypnotised, she reported no pain and was discharged immediately. Our case confirms the efficacy of hypnosis and demonstrates that it may be valuable as a sole anaesthetic method in selected cases. Hypnosis can prevent pain perception and surgical stress as a whole, comparing well with anaesthetic drugs.

  9. Assessment of chemical skin-sensitizing potency by an in vitro assay based on human dendritic cells.

    Science.gov (United States)

    Lambrechts, Nathalie; Vanheel, Hanne; Nelissen, Inge; Witters, Hilda; Van Den Heuvel, Rosette; Van Tendeloo, Viggo; Schoeters, Greet; Hooyberghs, Jef

    2010-07-01

    The skin-sensitizing potential of chemicals is an important concern for public health and thus a significant end point in the hazard identification process. To determine skin-sensitizing capacity, large research efforts focus on the development of assays, which do not require animals. As such, an in vitro test has previously been developed based on the differential expression of CREM and CCR2 transcripts in CD34(+) progenitor-derived dendritic cells (CD34-DC), which allows to classify chemicals as skin (non-)sensitizing. However, skin sensitization is not an all-or-none phenomenon, and up to now, the assessment of relative potency can only be derived using the in vivo local lymph node assay (LLNA). In our study, we analyzed the feasibility to predict the sensitizing potency, i.e., the LLNA EC3 values, of 15 skin sensitizers using in vitro data from the CD34-DC-based assay. Hereto, we extended the in vitro-generated gene expression data set by an additional source of information, the concentration of the compound that causes 20% cell damage (IC20) in CD34-DC. We statistically confirmed that this IC20 is linearly independent from the gene expression changes but that it does correlate with LLNA EC3 values. In a further analysis, we applied a robust linear regression with both IC20 and expression changes of CREM and CCR2 as explanatory variables. For 13 out of 15 compounds, a high linear correlation was established between the in vitro model and the LLNA EC3 values over a range of four orders of magnitude, i.e., from weak to extreme sensitizers.

  10. An in vitro skin sensitization assay termed EpiSensA for broad sets of chemicals including lipophilic chemicals and pre/pro-haptens.

    Science.gov (United States)

    Saito, Kazutoshi; Takenouchi, Osamu; Nukada, Yuko; Miyazawa, Masaaki; Sakaguchi, Hitoshi

    2016-12-10

    To evaluate chemicals (e.g. lipophilic chemicals, pre/pro-haptens) that are difficult to correctly evaluate using in vitro skin sensitization tests (e.g. DPRA, KeratinoSens or h-CLAT), we developed a novel in vitro test termed "Epidermal Sensitization Assay: EpiSensA" that uses reconstructed human epidermis. This assay is based on the induction of multiple marker genes (ATF3, IL-8, DNAJB4 and GCLM) related to two keratinocyte responses (inflammatory or cytoprotective) in the induction of skin sensitization. Here, we first confirmed the mechanistic relevance of these marker genes by focusing on key molecules that regulate keratinocyte responses in vivo (P2X7 for inflammatory and Nrf2 for cytoprotective responses). The up-regulation of ATF3 and IL-8, or DNAJB4 and GCLM induced by the representative sensitizer 2,4-dinitrochlorobenzene in human keratinocytes was significantly suppressed by a P2X7 specific antagonist KN-62, or by Nrf2 siRNA, respectively, which supported mechanistic relevance of marker genes. Moreover, the EpiSensA had sensitivity, specificity and accuracy of 93%, 100% and 93% for 29 lipophilic chemicals (logKow≥3.5), and of 96%, 75% and 88% for 43 hydrophilic chemicals including 11 pre/pro-haptens, compared with the LLNA. These results suggested that the EpiSensA could be a mechanism-based test applicable to broad sets of chemicals including lipophilic chemicals and pre/pro-haptens.

  11. Evaluation of a high-throughput peptide reactivity format assay for assessment of the skin sensitization potential of chemicals

    Directory of Open Access Journals (Sweden)

    Chin Lin eWong

    2016-03-01

    Full Text Available The direct peptide reactivity assay (DPRA is a validated method for in vitro assessment of the skin sensitization potential of chemicals. In the present work, we describe a peptide reactivity assay using 96-well plate format and systematically identified the optimal assay conditions for accurate and reproducible classification of chemicals with known sensitizing capacity. The aim of the research is to ensure that the analytical component of the peptide reactivity assay is robust, accurate and reproducible in accordance with criteria that are used for the validation of bioanalytical methods. Analytical performance was evaluated using quality control samples (QCs; heptapeptides at low, medium and high concentrations and incubation of control chemicals (chemicals with known sensitization capacity, weak, moderate, strong, extreme and non-sensitizers with each of three synthetic heptapeptides, viz Cor1-C420 (Ac-NKKCDLF, cysteine- (Ac-RFAACAA and lysine- (Ac-RFAAKAA containing heptapeptides. The optimal incubation temperature for all three heptapeptides was 25°C. Apparent heptapeptide depletion was affected by vial material composition. Incubation of test chemicals with Cor1-C420, showed that peptide depletion was unchanged in polypropylene vials over 3-days storage in an autosampler but this was not the case for borosilicate glass vials. For cysteine-containing heptapeptide, the concentration was not stable by day 3 post-incubation in borosilicate glass vials. Although the lysine-containing heptapeptide concentration was unchanged in both polypropylene and borosilicate glass vials, the apparent extent of lysine-containing heptapeptide depletion by ethyl acrylate, differed between polypropylene (24.7% and glass (47.3% vials. Additionally, the peptide-chemical complexes for Cor1-C420-cinnamaldehyde and cysteine-containing heptapeptide-2,4-dinitrochlorobenzene were partially reversible during 3-days of autosampler storage. These observations further

  12. The critical review of methodologies and approaches to assess the inherent skin sensitization potential (skin allergies) of chemicals. Part II

    DEFF Research Database (Denmark)

    Thyssen, Jacob P; Giménez-Arnau, Elena; Lepoittevin, Jean-Pierre

    2012-01-01

    To identify specific cases, classes or specific use situations of chemicals for which 'safety thresholds' or 'safety limits' were set (in regulations, standards, in scientific research/clinical work, etc.) and critically review the scientific and methodological parameters used to set those limits....

  13. Infrared sensing based sensitive skin

    Institute of Scientific and Technical Information of China (English)

    CAO Zheng-cai; FU Yi-li; WANG Shu-guo; JIN Bao

    2006-01-01

    Developed robotics sensitive skin is a modularized, flexible, mini-type array of infrared sensors with data processing capabilities, which can be used to cover the body of a robot. Depending on the infrared sensors and periphery processing circuit, robotics sensitive skin can in real-time provide existence and distance information about obstacles for robots within sensory areas. The methodology of designing sensitive skin and the algorithm of a mass of IR data fusion are presented. The experimental results show that the multi-joint robot with this sensitive skin can work autonomously in an unknown environment.

  14. Evaluation of the skin sensitizing potency of chemicals by using the existing methods and considerations of relevance for elicitation

    DEFF Research Database (Denmark)

    Basketter, David A; Andersen, Klaus E; Liden, Carola;

    2005-01-01

    The Technical Committee of Classification and Labelling dealing with harmonized classification of substances and classification criteria under Directive 67/548/EEC on behalf of the European Commission nominated an expert group on skin sensitization in order to investigate further the possibility...... for potency consideration of skin sensitizers for future development of the classification criteria. All substances and preparations should be classified on the basis of their intrinsic properties and should be labelled accordingly with the rules set up in the Directive 67/548/EEC. The classification should...... be the same under their full life cycle and in the case that there is no harmonized classification the substance or preparation should be self-classified by the manufacturer in accordance with the same criteria. The Directive does not apply to certain preparations in the finished state, such as medical...

  15. From genome-wide arrays to tailor-made biomarker readout - Progress towards routine analysis of skin sensitizing chemicals with GARD.

    Science.gov (United States)

    Forreryd, Andy; Zeller, Kathrin S; Lindberg, Tim; Johansson, Henrik; Lindstedt, Malin

    2016-12-01

    Allergic contact dermatitis (ACD) initiated by chemical sensitizers is an important public health concern. To prevent ACD, it is important to identify chemical allergens to limit the use of such compounds in various products. EU legislations, as well as increased mechanistic knowledge of skin sensitization have promoted development of non-animal based approaches for hazard classification of chemicals. GARD is an in vitro testing strategy based on measurements of a genomic biomarker signature. However, current GARD protocols are optimized for identification of predictive biomarker signatures, and not suitable for standardized screening. This study describes improvements to GARD to progress from biomarker discovery into a reliable and cost-effective assay for routine testing. Gene expression measurements were transferred to NanoString nCounter platform, normalization strategy was adjusted to fit serial arrival of testing substances, and a novel strategy to correct batch variations was presented. When challenging GARD with 29 compounds, sensitivity, specificity and accuracy could be estimated to 94%, 83% and 90%, respectively. In conclusion, we present a GARD workflow with improved sample capacity, retained predictive performance, and in a format adapted to standardized screening. We propose that GARD is ready to be considered as part of an integrated testing strategy for skin sensitization.

  16. Skin sensitization: Modeling based on skin metabolism simulation and formation of protein conjugates

    DEFF Research Database (Denmark)

    Dimitrov, Sabcho; Low, Lawrence; Patlewicz, Grace

    2005-01-01

    A quantitative structure-activity relationship (QSAR) system for estimating skin sensitization potency has been developed that incorporates skin metabolism and considers the potential of parent chemicals and/or their activated metabolites to react with skin proteins. A training set of diverse...... chemicals was compiled and their skin sensitization potency assigned to one of three classes. These three classes were, significant, weak, or nonsensitizing. Because skin sensitization potential depends upon the ability of chemicals to react with skin proteins either directly or after appropriate metabolism......, a metabolic simulator was constructed to mimic the enzyme activation of chemicals in the skin. This simulator contains 203 hierarchically ordered spontaneous and enzyme controlled reactions. Phase I and phase II metabolism were simulated by using 102 and 9 principal transformations, respectively. The covalent...

  17. 78 FR 68076 - Request for Information on Alternative Skin Sensitization Test Methods and Testing Strategies and...

    Science.gov (United States)

    2013-11-13

    ... workers and consumers exposed to skin-sensitizing chemicals and products. Pesticides and other marketed... relationship (SAR) models to predict skin sensitization. NICEATM collaboration with industry scientists to... sensitization. Participating in validation management groups sponsored by ICATM partner organizations to...

  18. Multiple chemical sensitivity

    DEFF Research Database (Denmark)

    Tran, Marie Thi Dao; Arendt-Nielsen, Lars; Kupers, Ron;

    2013-01-01

    BACKGROUND: Multiple Chemical Sensitivity (MCS) is a chronic condition characterized by recurrent, non-specific symptoms in response to chemically unrelated exposures in non-toxic concentrations. Although the pathophysiology of MCS remains unknown, central sensitization may be an important factor...

  19. In Chemico Evaluation of Tea Tree Essential Oils as Skin Sensitizers: Impact of the Chemical Composition on Aging and Generation of Reactive Species.

    Science.gov (United States)

    Avonto, Cristina; Chittiboyina, Amar G; Wang, Mei; Vasquez, Yelkaira; Rua, Diego; Khan, Ikhlas A

    2016-07-18

    Tea tree oil (TTO) is an essential oil obtained from the leaves of Melaleuca alternifolia, M. linariifolia, or M. dissitiflora. Because of the commercial importance of TTO, substitution or adulteration with other tea tree species (such as cajeput, niaouli, manuka, or kanuka oils) is common and may pose significant risks along with perceived health benefits. The distinctive nature, qualitative and quantitative compositional variation of these oils, is responsible for the various pharmacological as well as adverse effects. Authentic TTOs (especially aged ones) have been identified as potential skin sensitizers, while reports of adverse allergic reactions to the other tea trees essential oils are less frequent. Chemical sensitizers are usually electrophilic compounds, and in chemico methods have been developed to identify skin allergens in terms of their ability to bind to biological nucleophiles. However, little information is available on the assessment of sensitization potential of mixtures, such as essential oils, due to their complexity. In the present study, 10 "tea tree" oils and six major TTO constituents have been investigated for their sensitization potential using a fluorescence in chemico method. The reactivity of authentic TTOs was found to correlate with the age of the oils, while the majority of nonauthentic TTOs were less reactive, even after aging. Further thio-trapping experiments with DCYA and characterization by UHPLC-DAD-MS led to the identification of several possible DCYA-adducts which can be used to deduce the structure of the candidate reactive species. The major TTO components, terpinolene, α-terpinene, and terpinene-4-ol, were unstable under accelerated aging conditions, which led to the formation of several DCYA-adducts.

  20. A case of advanced mycosis fungoides with comprehensive skin and visceral organs metastasis:sensitive to chemical and biological therapy

    Institute of Scientific and Technical Information of China (English)

    Yi-Qian Liu; Wei-You Zhu; Yong-Qian Shu; Yan-Hong Gu

    2012-01-01

    Mycosis fungoides is a common cutaneousT-cell lymphoma, which is usually characterized by chronic, indolence progression, with absence of typical symptoms in early stage, metastasis to lymph nodes, bone marrow and visceral organs in later stage and ultimately progression to systemic lymphoma. It can result in secondary skin infection which is a frequent cause of death. At present, no curative therapy existed. Therapeutic purpose is to induce remission, reduce tumor burden and protect immune function of patients. A case of patient with advanced severe mycosis fungoides receivingCHOP plus interferon α-2a was reported here, with disease-free survival of 7 months and overall survival of over17.0 months, and current status as well as developments of mycosis fungoides were briefly introduced.

  1. A case of advanced mycosis fungoides with comprehensive skin and visceral organs metastasis: sensitive to chemical and biological therapy.

    Science.gov (United States)

    Liu, Yi-Qian; Zhu, Wei-You; Shu, Yong-Qian; Gu, Yan-Hong

    2012-08-01

    Mycosis fungoides is a common cutaneous T-cell lymphoma, which is usually characterized by chronic, indolence progression, with absence of typical symptoms in early stage, metastasis to lymph nodes, bone marrow and visceral organs in later stage and ultimately progression to systemic lymphoma. It can result in secondary skin infection which is a frequent cause of death. At present, no curative therapy existed. Therapeutic purpose is to induce remission, reduce tumor burden and protect immune function of patients. A case of patient with advanced severe mycosis fungoides receiving CHOP plus interferon α-2a was reported here, with disease-free survival of 7 months and overall survival of over 17.0 months, and current status as well as developments of mycosis fungoides were briefly introduced.

  2. Multiple Chemical Sensitivity

    DEFF Research Database (Denmark)

    Junge, Anne Gram

    Et voksende antal mennesker i Danmark oplever at være overfølsomme over for dufte og kemikalier. Imidlertid er den tilskrevne diagnose Multiple Chemical Sensitivity (MCS) ikke medicinsk anerkendt i Danmark pga. mangel på organiske og patofysiologisk basis for symptomerne. Dette speciale bygger på...

  3. Is skin penetration a determining factor in skin sensitization ...

    Science.gov (United States)

    Summary:Background. It is widely accepted that substances that cannot penetrate through the skin will not be sensitisers. Thresholds based on relevant physicochemical parameters such as a LogKow > 1 and a MW 1 is a true requirement for sensitisation.Methods. A large dataset of substances that had been evaluated for their skin sensitisation potential, together with measured LogKow values was compiled from the REACH database. The incidence of skin sensitisers relative to non-skin sensitisers below and above the LogKow = 1 threshold was evaluated. Results. 1482 substances with associated skin sensitisation outcomes and measured LogKow values were identified. 305 substances had a measured LogKow skin sensitisation above and below the LogKow = 1 threshold. Reaction chemistry considerations could explain the skin sensitisation observed for the 38 sensitisers with a LogKow skin sensitisation potential and potency. Using the REACH data extracted to test out the validity of common assumptions in the skin sensitization AOP. Builds on trying to develop a proof of concept IATA

  4. Skin Sensitizing Potency of Halogenated Platinum Salts.

    Science.gov (United States)

    The relationship between occupational exposure to halogenated platinum (Pt) salts and Pt-specific allergic sensitization is well-established. Although human case reports and clinical studies demonstrate that Pt salts are potent skin sensitizers, no studies have been published tha...

  5. Quantitative risk assessment for skin sensitization: Success or failure?

    Science.gov (United States)

    Kimber, Ian; Gerberick, G Frank; Basketter, David A

    2017-02-01

    Skin sensitization is unique in the world of toxicology. There is a combination of reliable, validated predictive test methods for identification of skin sensitizing chemicals, a clearly documented and transparent approach to risk assessment, and effective feedback from dermatology clinics around the world delivering evidence of the success or failure of the hazard identification/risk assessment/management process. Recent epidemics of contact allergy, particularly to preservatives, have raised questions of whether the safety/risk assessment process is working in an optimal manner (or indeed is working at all!). This review has as its focus skin sensitization quantitative risk assessment (QRA). The core toxicological principles of QRA are reviewed, and evidence of use and misuse examined. What becomes clear is that skin sensitization QRA will only function adequately if two essential criteria are met. The first is that QRA is applied rigourously, and the second is that potential exposure to the sensitizing substance is assessed adequately. This conclusion will come as no surprise to any toxicologist who appreciates the basic premise that "risk = hazard x exposure". Accordingly, use of skin sensitization QRA is encouraged, not least because the essential feedback from dermatology clinics can be used as a tool to refine QRA in situations where this risk assessment tool has not been properly used.

  6. A fluorescence high throughput screening method for the detection of reactive electrophiles as potential skin sensitizers

    Science.gov (United States)

    Skin sensitization is an important toxicological end-point in the risk assessment of chemical allergens. Because of the complexity of the biological mechanisms associated with skin sensitization integrated approaches combining different chemical, biological and in silico methods are recommended to r...

  7. Fragment-based prediction of skin sensitization using recursive partitioning.

    Science.gov (United States)

    Lu, Jing; Zheng, Mingyue; Wang, Yong; Shen, Qiancheng; Luo, Xiaomin; Jiang, Hualiang; Chen, Kaixian

    2011-09-01

    Skin sensitization is an important toxic endpoint in the risk assessment of chemicals. In this paper, structure-activity relationships analysis was performed on the skin sensitization potential of 357 compounds with local lymph node assay data. Structural fragments were extracted by GASTON (GrAph/Sequence/Tree extractiON) from the training set. Eight fragments with accuracy significantly higher than 0.73 (precursive partitioning tree (RP tree) for classification. The balanced accuracy of the training set, test set I, and test set II in the leave-one-out model were 0.846, 0.800, and 0.809, respectively. The results highlight that fragment-based RP tree is a preferable method for identifying skin sensitizers. Moreover, the selected fragments provide useful structural information for exploring sensitization mechanisms, and RP tree creates a graphic tree to identify the most important properties associated with skin sensitization. They can provide some guidance for designing of drugs with lower sensitization level.

  8. Mass-sensitive chemical preconcentrator

    Science.gov (United States)

    Manginell, Ronald P.; Adkins, Douglas R.; Lewis, Patrick R.

    2007-01-30

    A microfabricated mass-sensitive chemical preconcentrator actively measures the mass of a sample on an acoustic microbalance during the collection process. The microbalance comprises a chemically sensitive interface for collecting the sample thereon and an acoustic-based physical transducer that provides an electrical output that is proportional to the mass of the collected sample. The acoustic microbalance preferably comprises a pivot plate resonator. A resistive heating element can be disposed on the chemically sensitive interface to rapidly heat and release the collected sample for further analysis. Therefore, the mass-sensitive chemical preconcentrator can optimize the sample collection time prior to release to enable the rapid and accurate analysis of analytes by a microanalytical system.

  9. Sensitive skin and stratum corneum reactivity to household cleaning products.

    Science.gov (United States)

    Goffin, V; Piérard-Franchimont, C; Piérard, G E

    1996-02-01

    Products intended for individuals with sensitive skin are being increasingly developed by formulators of household cleaning products. However, there is currently no consensus about the definition and recognition of the biological basis of sensitive skin. We sought to determine the relation between the nature of environmental threat perceived as aggressive by panelists, and the stratum corneum reactivity to household cleaning products as measured by the corneosurfametry test. Results indicate substantial differences in irritancy potential between proprietary products. Corneosurfametry data show significant differences in stratum corneum reactivity between, on the one hand, individuals with either non-sensitive skin or skin sensitive to climate/fabrics, and, on the other hand, individuals with detergent-sensitive skin. It is concluded that sensitive skin is not one single condition. Sound information in rating detergent-sensitive skin may be gained by corneosurfametry.

  10. Evaluating a Skin Sensitization Model and Examining Common Assumptions of Skin Sensitizers (QSAR conference)

    Science.gov (United States)

    Skin sensitization is an adverse outcome that has been well studied over many decades. Knowledge of the mechanism of action was recently summarized using the Adverse Outcome Pathway (AOP) framework as part of the OECD work programme (OECD, 2012). Currently there is a strong focus...

  11. Evaluating a Skin Sensitization Model and Examining Common Assumptions of Skin Sensitizers (ASCCT meeting)

    Science.gov (United States)

    Skin sensitization is an adverse outcome that has been well studied over many decades. It was summarized using the adverse outcome pathway (AOP) framework as part of the OECD work programme (OECD, 2012). Currently there is a strong focus on how AOPs can be applied for different r...

  12. Proteomic allergen-peptide/protein interaction assay for the identification of human skin sensitizers

    NARCIS (Netherlands)

    Dietz, L.; Kinzebach, S.; Ohnesorge, S.; Franke, B.; Goette, I.; Koenig-Gressel, D.; Thierse, H.J.

    2013-01-01

    Modification of proteins by skin sensitizers is a pivotal step in T cell mediated allergic contact dermatitis (ACD). In this process small reactive chemicals interact covalently or non-covalently with cellular or extracellular skin self-proteins or self-peptides to become recognized by the human imm

  13. In chemico evaluation of tea tree essential oils as skin sensitizers. Impact of the chemical composition on aging and generation of reactive species

    Science.gov (United States)

    Tea tree oil (TTO) is a popular skin remedy obtained from the leaves of Melaleuca alternifolia, M. linariifolia or M dissitiflora. Due to the commercial importance ofTTO, substitution or adulteration with other tea tree species (such as cajeput, niaouli, manuka and kanuka oils) is common and may p...

  14. Prognostic value of asymptomatic skin sensitization to aeroallergens

    DEFF Research Database (Denmark)

    Bødtger, Uffe

    2004-01-01

    immunological mechanisms in asymptomatic skin sensitization might provide new insights into the natural history and treatment of respiratory allergy. RECENT FINDINGS: Research on asymptomatic skin sensitization is rare, and the present review unites previous studies with recent findings. It is a common...... positive skin test must be ruled out before allergen avoidance measures are initiated. SUMMARY: Surprisingly few papers exist on asymptomatic skin sensitization epidemiology and immunology, despite the intriguing question as to why symptoms do not develop in IgE-sensitized patients. It is a common...

  15. Multistage chemical carcinogenesis in mouse skin

    Energy Technology Data Exchange (ETDEWEB)

    Slaga, T.J.; Fischer, S.M.; Weeks, C.E.; Klein-Szanto, A.J.P.

    1979-01-01

    Skin tumors in mice can be induced by the sequential application of a subthreshold dose of a carcinogen (initiation phase) followed by repetitive treatment with a noncarcinogenic tumor promoter. The initiation phase requires only a single application of either a direct acting carcinogen or a procarcinogen which has to be metabolized before being active and is essentially an irreversible step which probably involves a somatic cell mutation. There is a good correlation between the skin tumor initiating activites of several polycyclic aromatic hydrocarbons (PAH) and their ability to bind covalently to epidermal DNA. Laboratory results suggest that bay region diol-epoxides are the ultimate carcinogenic form of PAH carcinogens. Potent inhibitors and stimulators of PAH tumor initiation appear to affect the level of the PAH diol-epoxide reacting with specific DNA bases. Reecent data suggests that the tumor promotion stage involves at least three important steps: (1) the induction of embryonic looking cells (dark cells) in adult epidermis; (2) an increased production of epidermal prostaglandins and polyamines; (3) sustained proliferation of dark cells. Retinoic acid specifically inhibits step two whereas the anti-inflammatory steriod fluocinolone acetonide is a potent inhibitor of steps one and three. The mechanism and the importance of a specific sequence for each step in chemical carcinogenesis in mouse skin are detailed.

  16. Machine Learning Approaches for Predicting Human Skin Sensitization Hazard

    Science.gov (United States)

    One of ICCVAM’s top priorities is the development and evaluation of non-animal approaches to identify potential skin sensitizers. The complexity of biological events necessary for a substance to elicit a skin sensitization reaction suggests that no single in chemico, in vit...

  17. Determinants of skin sensitivity to solar irradiation

    NARCIS (Netherlands)

    Broekmans, W.M.R.; Vink, A.A.; Boelsma, E.; Klöpping-Ketelaars, W.A.A.; Tijburg, L.B.M.; Veer, P. van 't; Poppel, G. van; Kardinaal, A.F.M.

    2003-01-01

    Background: Acute effects of UV irradiation include UV-induced erythema. Sunlight plays an important role in the development of skin cancer. Several predictive factors of UV-induced erythema could also be predictive for skin cancer. Objective: Our objective was to quantitatively assess phenotypical

  18. Chemical ecology of interactions between human skin microbiota and mosquitoes

    NARCIS (Netherlands)

    Verhulst, N.O.; Takken, W.; Dicke, M.; Schraa, G.; Smallegange, R.C.

    2010-01-01

    Microbiota on the human skin plays a major role in body odour production. The human microbial and chemical signature displays a qualitative and quantitative correlation. Genes may influence the chemical signature by shaping the composition of the microbiota. Recent studies on human skin microbiota,

  19. Prediction of Skin Sensitization with a Particle Swarm Optimized Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Chenzhong Cao

    2009-07-01

    Full Text Available Skin sensitization is the most commonly reported occupational illness, causing much suffering to a wide range of people. Identification and labeling of environmental allergens is urgently required to protect people from skin sensitization. The guinea pig maximization test (GPMT and murine local lymph node assay (LLNA are the two most important in vivo models for identification of skin sensitizers. In order to reduce the number of animal tests, quantitative structure-activity relationships (QSARs are strongly encouraged in the assessment of skin sensitization of chemicals. This paper has investigated the skin sensitization potential of 162 compounds with LLNA results and 92 compounds with GPMT results using a support vector machine. A particle swarm optimization algorithm was implemented for feature selection from a large number of molecular descriptors calculated by Dragon. For the LLNA data set, the classification accuracies are 95.37% and 88.89% for the training and the test sets, respectively. For the GPMT data set, the classification accuracies are 91.80% and 90.32% for the training and the test sets, respectively. The classification performances were greatly improved compared to those reported in the literature, indicating that the support vector machine optimized by particle swarm in this paper is competent for the identification of skin sensitizers.

  20. In silico risk assessment for skin sensitization using artificial neural network analysis.

    Science.gov (United States)

    Tsujita-Inoue, Kyoko; Atobe, Tomomi; Hirota, Morihiko; Ashikaga, Takao; Kouzuki, Hirokazu

    2015-04-01

    The sensitizing potential of chemicals is usually identified and characterized using in vivo methods such as the murine local lymph node assay (LLNA). Due to regulatory constraints and ethical concerns, alternatives to animal testing are needed to predict the skin sensitization potential of chemicals. For this purpose, an integrated evaluation system employing multiple in vitro and in silico parameters that reflect different aspects of the sensitization process seems promising. We previously reported that LLNA thresholds could be well predicted by using an artificial neural network (ANN) model, designated iSENS ver. 2 (integrating in vitro sensitization tests version 2), to analyze data obtained from in vitro tests focused on different aspects of skin sensitization. Here, we examined whether LLNA thresholds could be predicted by ANN using in silico-calculated descriptors of the three-dimensional structures of chemicals. We obtained a good correlation between predicted LLNA thresholds and reported values. Furthermore, combining the results of the in vitro (iSENS ver. 2) and in silico models reduced the number of chemicals for which the potency category was under-estimated. In conclusion, the ANN model using in silico parameters was shown to be have useful predictive performance. Further, our results indicate that the combination of this model with a predictive model using in vitro data represents a promising approach for integrated risk assessment of skin sensitization potential of chemicals.

  1. Tactile-direction-sensitive and stretchable electronic skins based on human-skin-inspired interlocked microstructures.

    Science.gov (United States)

    Park, Jonghwa; Lee, Youngoh; Hong, Jaehyung; Lee, Youngsu; Ha, Minjeong; Jung, Youngdo; Lim, Hyuneui; Kim, Sung Youb; Ko, Hyunhyub

    2014-12-23

    Stretchable electronic skins with multidirectional force-sensing capabilities are of great importance in robotics, prosthetics, and rehabilitation devices. Inspired by the interlocked microstructures found in epidermal-dermal ridges in human skin, piezoresistive interlocked microdome arrays are employed for stress-direction-sensitive, stretchable electronic skins. Here we show that these arrays possess highly sensitive detection capability of various mechanical stimuli including normal, shear, stretching, bending, and twisting forces. Furthermore, the unique geometry of interlocked microdome arrays enables the differentiation of various mechanical stimuli because the arrays exhibit different levels of deformation depending on the direction of applied forces, thus providing different sensory output patterns. In addition, we show that the electronic skins attached on human skin in the arm and wrist areas are able to distinguish various mechanical stimuli applied in different directions and can selectively monitor different intensities and directions of air flows and vibrations.

  2. A new ten-item questionnaire for assessing sensitive skin: the Sensitive Scale-10.

    Science.gov (United States)

    Misery, Laurent; Jean-Decoster, Catherine; Mery, Sophie; Georgescu, Victor; Sibaud, Vincent

    2014-11-01

    Sensitive skin is common but until now there has been no scale for measuring its severity. The Sensitive Scale is a new scale with a 14-item and a 10-item version that was tested in 11 countries in different languages on 2,966 participants. The aim of this study was to validate the pertinence of using the Sensitive Scale to measure the severity of sensitive skin. The internal consistency was high. Correlations with the dry skin type, higher age, female gender, fair phototypes and Dermatology Life Quality Index were found. Using the 10-item version appeared to be preferable because it was quicker and easier to complete, with the same internal consistency and the 4 items that were excluded were very rarely observed in patients. The mean initial scores were around 44/140 and 37/100. The use of a cream for sensitive skin showed the pertinence of the scale before and after treatment.

  3. Prediction of skin sensitizers using alternative methods to animal experimentation.

    Science.gov (United States)

    Johansson, Henrik; Lindstedt, Malin

    2014-07-01

    Regulatory frameworks within the European Union demand that chemical substances are investigated for their ability to induce sensitization, an adverse health effect caused by the human immune system in response to chemical exposure. A recent ban on the use of animal tests within the cosmetics industry has led to an urgent need for alternative animal-free test methods that can be used for assessment of chemical sensitizers. To date, no such alternative assay has yet completed formal validation. However, a number of assays are in development and the understanding of the biological mechanisms of chemical sensitization has greatly increased during the last decade. In this MiniReview, we aim to summarize and give our view on the recent progress of method development for alternative assessment of chemical sensitizers. We propose that integrated testing strategies should comprise complementary assays, providing measurements of a wide range of mechanistic events, to perform well-educated risk assessments based on weight of evidence.

  4. Integrated Computational Solution for Predicting Skin Sensitization Potential of Molecules.

    Directory of Open Access Journals (Sweden)

    Konda Leela Sarath Kumar

    Full Text Available Skin sensitization forms a major toxicological endpoint for dermatology and cosmetic products. Recent ban on animal testing for cosmetics demands for alternative methods. We developed an integrated computational solution (SkinSense that offers a robust solution and addresses the limitations of existing computational tools i.e. high false positive rate and/or limited coverage.The key components of our solution include: QSAR models selected from a combinatorial set, similarity information and literature-derived sub-structure patterns of known skin protein reactive groups. Its prediction performance on a challenge set of molecules showed accuracy = 75.32%, CCR = 74.36%, sensitivity = 70.00% and specificity = 78.72%, which is better than several existing tools including VEGA (accuracy = 45.00% and CCR = 54.17% with 'High' reliability scoring, DEREK (accuracy = 72.73% and CCR = 71.44% and TOPKAT (accuracy = 60.00% and CCR = 61.67%. Although, TIMES-SS showed higher predictive power (accuracy = 90.00% and CCR = 92.86%, the coverage was very low (only 10 out of 77 molecules were predicted reliably.Owing to improved prediction performance and coverage, our solution can serve as a useful expert system towards Integrated Approaches to Testing and Assessment for skin sensitization. It would be invaluable to cosmetic/ dermatology industry for pre-screening their molecules, and reducing time, cost and animal testing.

  5. Risk group, skin lesion history, and sun sensitivity reliability in squamous cell skin cancer progression.

    Science.gov (United States)

    Clouser, Mary C; Harris, Robin B; Roe, Denise J; Saboda, Kathylynn; Ranger-Moore, James; Duckett, Laura; Alberts, David S

    2006-11-01

    In studies of skin cancer, participants are often classified into risk groups based on self-reported history of sun exposure or skin characteristics. We sought to determine the reliability of self-reported skin characteristics among participants of a study to evaluate markers for nonmelanoma skin cancer (NMSC). Multiple questionnaires and screening protocols were administered over a 3-month period to individuals from three risk groups: existing sun damage on forearms but no visible actinic keratoses (n = 91), visible actinic keratoses (n = 38), and history of resected squamous cell skin cancer in the last 12 months (n = 35). We assessed consistency of risk group assignment between telephone screen and study dermatologist assignment, self-reported sun sensitivity (telephone recruitment form versus participant completed profile), and self-reported history of NMSC skin lesions (telephone recruitment form versus health history). There was substantial agreement between probable risk group and final assignment (kappa = 0.76; 95% confidence interval, 0.65-0.85) and agreement did not differ by gender. Agreement for self-reported sun sensitivity was moderate (kappa weighted = 0.46; 95% confidence interval, 0.36-0.56) with higher agreement for women. For self-reported NMSC lesion history between two interviews, 24 days apart, kappa estimates ranged from 0.66 to 0.78 and were higher for women than men. Overall, there was evidence for substantial reproducibility related to risk group assignment and self-reported history of NMSC, with self-reported sun sensitivity being less reliable. In all comparisons, women had higher kappa values than men. These results suggest that self-reported measures of skin cancer risk are reasonably reliable for use in screening subjects into studies.

  6. Epoxy resin monomers with reduced skin sensitizing potency.

    Science.gov (United States)

    O'Boyle, Niamh M; Niklasson, Ida B; Tehrani-Bagha, Ali R; Delaine, Tamara; Holmberg, Krister; Luthman, Kristina; Karlberg, Ann-Therese

    2014-06-16

    Epoxy resin monomers (ERMs), especially diglycidyl ethers of bisphenol A and F (DGEBA and DGEBF), are extensively used as building blocks for thermosetting polymers. However, they are known to commonly cause skin allergy. This research describes a number of alternative ERMs, designed with the aim of reducing the skin sensitizing potency while maintaining the ability to form thermosetting polymers. The compounds were designed, synthesized, and assessed for sensitizing potency using the in vivo murine local lymph node assay (LLNA). All six epoxy resin monomers had decreased sensitizing potencies compared to those of DGEBA and DGEBF. With respect to the LLNA EC3 value, the best of the alternative monomers had a value approximately 2.5 times higher than those of DGEBA and DGEBF. The diepoxides were reacted with triethylenetetramine, and the polymers formed were tested for technical applicability using thermogravimetric analysis and differential scanning calorimetry. Four out of the six alternative ERMs gave polymers with a thermal stability comparable to that obtained with DGEBA and DGEBF. The use of improved epoxy resin monomers with less skin sensitizing effects is a direct way to tackle the problem of contact allergy to epoxy resin systems, particularly in occupational settings, resulting in a reduction in the incidence of allergic contact dermatitis.

  7. The pilosebaceous unit—a phthalate-induced pathway to skin sensitization

    Energy Technology Data Exchange (ETDEWEB)

    Simonsson, Carl, E-mail: carl.simonsson@chem.gu.se [Department of Chemistry and Molecular Biology, University of Gothenburg, SE-412 96, Gothenburg (Sweden); Stenfeldt, Anna-Lena; Karlberg, Ann-Therese [Department of Chemistry and Molecular Biology, University of Gothenburg, SE-412 96, Gothenburg (Sweden); Ericson, Marica B., E-mail: marica.ericson@physics.gu.se [Department of Physics, University of Gothenburg, SE-412 96, Gothenburg (Sweden); Jonsson, Charlotte A.M. [Department of Chemistry and Molecular Biology, University of Gothenburg, SE-412 96, Gothenburg (Sweden)

    2012-10-01

    Allergic contact dermatitis (ACD) is caused by low-molecular weight compounds called haptens. It has been shown that the potency of haptens can depend on the formulation in which they are applied on the skin. Specifically the sensitization potency of isothiocyanates, a group of haptens which can be released from e.g. adhesive tapes and neoprene materials, increases with the presence of phthalates; however, the underlying mechanisms are not clear. A better understanding of the mechanisms governing the potency of haptens is important, e.g. to improve the risk assessment and the formulation of chemicals in consumer products. In this study we have explored phthalate-induced effects on the sensitization potency, skin distribution, and reactivity of fluorescent model isothiocyanate haptens using non-invasive two-photon microscopy to provide new insights regarding vehicle effects in ACD. The data presented in this paper indicate that the sensitization potency of isothiocyanates increases when applied in combination with dibutylphthalate due to a specific uptake via the pilosebaceous units. The results highlight the importance of shunt pathways when evaluating the bioavailability of skin sensitizers. The findings also indicate that vehicle-dependent hapten reactivity towards stratum corneum proteins regulates the bioavailability, and thus the potency, of skin sensitizers. -- Highlights: ► Vehicle effects on sensitization potency were investigated in the LLNA. ► In vivo cutaneous absorption of contact sensitizers was visualized using TPM. ► Sensitizing potency of isothiocyanates depends on the presence of a phthalate. ► Phthalate induced cutaneous absorption via the pilosebaceous units. ► Vehicle-dependent reactivity regulates sensitization potency.

  8. Asymptomatic skin sensitization to birch predicts later development of birch pollen allergy in adults

    DEFF Research Database (Denmark)

    Bodtger, Uffe; Poulsen, Lars K.; Malling, Hans-Jørgen

    2003-01-01

    The skin prick test is the allergologic test of choice, but asymptomatic skin sensitization to aeroallergens is common. However, no data in the literature describe the clinical phenotype of asymptomatic sensitized adults....

  9. Attenuated noradrenergic sensitivity during local cooling in aged human skin

    Science.gov (United States)

    Thompson, Caitlin S; Holowatz, Lacy A; Kenney, W. Larry

    2005-01-01

    Reflex-mediated cutaneous vasoconstriction (VC) is impaired in older humans; however, it is unclear whether this blunted VC also occurs during local cooling, which mediates VC through different mechanisms. We tested the hypothesis that the sensitization of cutaneous vessels to noradrenaline (NA) during direct skin cooling seen in young skin is blunted in aged skin. In 11 young (18–30 years) and 11 older (62–76 years) men and women, skin blood flow was monitored at two forearm sites with laser Doppler (LD) flowmetry while local skin temperature was cooled and clamped at 24°C. Cutaneous vascular conductance (CVC; LD flux/mean arterial pressure) was expressed as percentage change from baseline (%ΔCVCbase). At one site, five doses of NA (10−10–10−2m) were sequentially infused via intradermal microdialysis during cooling while the other 24°C site served as control (Ringer solution + cooling). At control sites, VC due to cooling alone was similar in young versus older (−54 ± 5 versus −56 ± 3%ΔCVCbase, P= 0.46). In young, NA infusions induced additional dose-dependent VC (10−8, 10−6, 10−4 and 10−2m: −70 ± 2, −72 ± 3, −78 ± 3 and −79 ± 4%ΔCVCbase; P older skin does not display enhanced VC capacity until treated with saturating doses of NA, possibly due to age-associated decrements in Ca2+ availability or α2C-adrenoceptor function. PMID:15705648

  10. What is sensitive skin? A systematic literature review of objective measurements

    NARCIS (Netherlands)

    Richters, R.J.H.; Falcone, D.; Uzunbajakava, N.; Verkruysse, W.; Erp, P.E.J. van; Kerkhof, P.C.M. van de

    2015-01-01

    Despite sensitive skin being highly prevalent, no consensus on the definition and pathomechanism of sensitive skin exists. Here we report the results of a systematic literature review of diagnostic methods for sensitive skin at clinical, histological and biophysical levels. A systematic search revea

  11. Effect of chemical peeling on the skin in relation to UV irradiation.

    Science.gov (United States)

    Funasaka, Yoko; Abdel-Daim, Mohamed; Kawana, Seiji; Nishigori, Chikako

    2012-07-01

    Chemical peeling is one of the dermatological treatments available for certain cutaneous diseases and conditions or improvement of cosmetic appearance of photoaged skin. However, it needs to be clarified whether the repetitive procedure of chemical peeling on photodamaged skin is safe and whether the different chemicals used for peeling results in similar outcomes or not. In this article, we reviewed the effect of peeling or peeling agents on the skin in relation to ultraviolet (UV) radiation. The pretreatment of peeling agents usually enhance UV sensitivity by inducing increased sunburn cell formation, lowering minimum erythematous dose and increasing cyclobutane pyrimidine dimers. However, this sensitivity is reversible and recovers to normal after 1-week discontinuation. Using animals, the chronic effect of peeling and peeling agents was shown to prevent photocarcinogenesis. There is also an in vitro study using culture cells to know the detailed mechanisms of peeling agents, especially on cell proliferation and apoptotic changes via activating signalling cascades and oxidative stress. It is important to understand the effect of peeling agents on photoaged skin and to know how to deal with UV irradiation during the application of peeling agents and treatment of chemical peeling in daily life.

  12. Chemically sensitive interfaces on SAW devices

    Energy Technology Data Exchange (ETDEWEB)

    Ricco, A.J.; Martin, S.J. [Sandia National Labs., Albuquerque, NM (United States); Crooks, R.M.; Xu, Chuanjing [Texas A and M Univ., College Station, TX (United States); Allred, R.E. [Adherent Technologies, Inc., Albuquerque, NM (United States)

    1993-11-01

    Using surface acoustic wave (SAW) devices, three approaches to the effective use of chemically sensitive interfaces that are not highly chemically selective have been examined: (1) molecular identification from time-resolved permeation transients; (2) using multifrequency SAW devices to determine the frequency dependence of analyte/film interactions; (3) use of an array of SAW devices bearing diverse chemically sensitive interfaces to produce a distinct response pattern for each analyte. In addition to their well-known sensitivity to mass changes (0.0035 monolayer of N{sub 2} can be measured), SAW devices respond to the mechanical and electronic properties of thin films, enhancing response information content but making a thorough understanding of the perturbation critical. Simultaneous measurement of changes in frequency and attenuation, which can provide the information necessary to determine the type of perturbation, are used as part of the above discrimination schemes.

  13. Chemical and engineering approaches to enable organic field-effect transistors for electronic skin applications.

    Science.gov (United States)

    Sokolov, Anatoliy N; Tee, Benjamin C-K; Bettinger, Christopher J; Tok, Jeffrey B-H; Bao, Zhenan

    2012-03-20

    Skin is the body's largest organ and is responsible for the transduction of a vast amount of information. This conformable material simultaneously collects signals from external stimuli that translate into information such as pressure, pain, and temperature. The development of an electronic material, inspired by the complexity of this organ is a tremendous, unrealized engineering challenge. However, the advent of carbon-based electronics may offer a potential solution to this long-standing problem. In this Account, we describe the use of an organic field-effect transistor (OFET) architecture to transduce mechanical and chemical stimuli into electrical signals. In developing this mimic of human skin, we thought of the sensory elements of the OFET as analogous to the various layers and constituents of skin. In this fashion, each layer of the OFET can be optimized to carry out a specific recognition function. The separation of multimodal sensing among the components of the OFET may be considered a "divide and conquer" approach, where the electronic skin (e-skin) can take advantage of the optimized chemistry and materials properties of each layer. This design of a novel microstructured gate dielectric has led to unprecedented sensitivity for tactile pressure events. Typically, pressure-sensitive components within electronic configurations have suffered from a lack of sensitivity or long mechanical relaxation times often associated with elastomeric materials. Within our method, these components are directly compatible with OFETs and have achieved the highest reported sensitivity to date. Moreover, the tactile sensors operate on a time scale comparable with human skin, making them ideal candidates for integration as synthetic skin devices. The methodology is compatible with large-scale fabrication and employs simple, commercially available elastomers. The design of materials within the semiconductor layer has led to the incorporation of selectivity and sensitivity within

  14. Sensitive Chemical Compass Assisted by Quantum Criticality

    CERN Document Server

    Cai, C Y; Quan, H T; Sun, C P

    2011-01-01

    The radical-pair-based chemical reaction could be used by birds for the navigation via the geomagnetic direction. An inherent physical mechanism is that the quantum coherent transition from a singlet state to triplet states of the radical pair could response to the weak magnetic field and be sensitive to the direction of such a field and then results in different photopigments in the avian eyes to be sensed. Here, we propose a quantum bionic setup for the ultra-sensitive probe of a weak magnetic field based on the quantum phase transition of the environments of the two electrons in the radical pair. We prove that the yield of the chemical products via the recombination from the singlet state is determined by the Loschmidt echo of the environments with interacting nuclear spins. Thus quantum criticality of environments could enhance the sensitivity of the detection of the weak magnetic field.

  15. Contact sensitizers induce skin inflammation via ROS production and hyaluronic acid degradation.

    Directory of Open Access Journals (Sweden)

    Philipp R Esser

    Full Text Available BACKGROUND: Allergic contact dermatitis (ACD represents a severe health problem with increasing worldwide prevalence. It is a T cell-mediated skin disease induced by protein-reactive organic and inorganic chemicals. A key feature of contact allergens is their ability to trigger an innate immune response that leads to skin inflammation. Previous evidence from the mouse contact hypersensitivity (CHS model suggests a role for endogenous activators of innate immune signaling. Here, we analyzed the role of contact sensitizer induced ROS production and concomitant changes in hyaluronic acid metabolism on CHS responses. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed in vitro and in vivo ROS production using fluorescent ROS detection reagents. HA fragmentation was determined by gel electrophoresis. The influence of blocking ROS production and HA degradation by antioxidants, hyaluronidase-inhibitor or p38 MAPK inhibitor was analyzed in the murine CHS model. Here, we demonstrate that organic contact sensitizers induce production of reactive oxygen species (ROS and a concomitant breakdown of the extracellular matrix (ECM component hyaluronic acid (HA to pro-inflammatory low molecular weight fragments in the skin. Importantly, inhibition of either ROS-mediated or enzymatic HA breakdown prevents sensitization as well as elicitation of CHS. CONCLUSIONS/SIGNIFICANCE: These data identify an indirect mechanism of contact sensitizer induced innate inflammatory signaling involving the breakdown of the ECM and generation of endogenous danger signals. Our findings suggest a beneficial role for anti-oxidants and hyaluronidase inhibitors in prevention and treatment of ACD.

  16. Sensitive chemical compass assisted by quantum criticality

    Science.gov (United States)

    Cai, C. Y.; Ai, Qing; Quan, H. T.; Sun, C. P.

    2012-02-01

    A radical-pair-based chemical reaction might be used by birds for navigation via the geomagnetic direction. The inherent physical mechanism is that the quantum coherent transition from a singlet state to triplet states of the radical pair could respond to a weak magnetic field and be sensitive to the direction of such a field; this then results in different photopigments to be sensed by the avian eyes. Here, we propose a quantum bionic setup, inspired by the avian compass, as an ultrasensitive probe of a weak magnetic field based on the quantum phase transition of the environments of the two electrons in the radical pair. We prove that the yield of the chemical products via recombination from the singlet state is determined by the Loschmidt echo of the environments with interacting nuclear spins. Thus quantum criticality of environments could enhance the sensitivity of detection of weak magnetic fields.

  17. Chemical microsensors with molecularly imprinted sensitive layers

    Science.gov (United States)

    Dickert, Franz L.; Greibl, Wolfgang; Sikorski, Renatus; Tortschanoff, Matthias; Weber, K.; Bulst, W. E.; Fischerauer, G.

    1998-12-01

    The bottleneck in the development of chemical sensors is the design of the coatings for chemical recognition of the analyte. One pronounced method is to tailor supramolecular cavities for different analytes. Polyfunctional linkers or the embedding of these materials in a polymeric matrix can improve stability and response time of the sensor. An even more favorable method to synthesize chemically sensitive layers is realized by molecular imprinting, since a rigid polymer can be generated directly on the transducer of interest and may be included in its production process. The analyte of interest acts as a template during the polymerization process and is evaporated or extracted by suitable solvents. Due to the cavities formed this polymer enriches analyte molecules, which can be detected by mass- sensitive devices such as QMB or SAW resonators or by optical measurements. This procedure allows both the detection of polycyclic aromatic hydrocarbons (PAHs) with fluorescence or mass sensitive devices. If the print PAHs are varied the polymers are tuned to the desired analyte. The enrichment of solvent vapors or other uncolored specimen by the layer can also be followed by the embedding of carbenium ions used as optical labels.

  18. Skin Sensitive Difference of Human Body Sections under Clothing-Smirnov Test of Skin Surface Temperatures' Dynamic Changing

    Institute of Scientific and Technical Information of China (English)

    LI Jun; WU Hai-yan; WANG Yun-yi

    2004-01-01

    Skin sensitive difference of human body sections under clothing is the theoretic foundation of thermal insulation clothing design.By a new method of researching on clothing comfort perception,the skin temperature live changing procedure of human body sections affected by the same cold stimulation is inspected.Furthermore with the Smirnov test the skin temperatures dynamic changing patterns of main human body sections are obtained.

  19. Sensitivity analysis on an AC600 aluminum skin component

    Science.gov (United States)

    Mendiguren, J.; Agirre, J.; Mugarra, E.; Galdos, L.; Saenz de Argandoña, E.

    2016-08-01

    New materials are been introduced on the car body in order to reduce weight and fulfil the international CO2 emission regulations. Among them, the application of aluminum alloys is increasing for skin panels. Even if these alloys are beneficial for the car design, the manufacturing of these components become more complex. In this regard, numerical simulations have become a necessary tool for die designers. There are multiple factors affecting the accuracy of these simulations e.g. hardening, anisotropy, lubrication, elastic behavior. Numerous studies have been conducted in the last years on high strength steels component stamping and on developing new anisotropic models for aluminum cup drawings. However, the impact of the correct modelling on the latest aluminums for the manufacturing of skin panels has been not yet analyzed. In this work, first, the new AC600 aluminum alloy of JLR-Novelis is characterized for anisotropy, kinematic hardening, friction coefficient, elastic behavior. Next, a sensitivity analysis is conducted on the simulation of a U channel (with drawbeads). Then, the numerical an experimental results are correlated in terms of springback and failure. Finally, some conclusions are drawn.

  20. Multiple chemical sensitivity: a 1999 consensus.

    Science.gov (United States)

    1999-01-01

    Consensus criteria for the definition of multiple chemical sensitivity (MCS) were first identified in a 1989 multidisciplinary survey of 89 clinicians and researchers with extensive experience in, but widely differing views of, MCS. A decade later, their top 5 consensus criteria (i.e., defining MCS as [1] a chronic condition [2] with symptoms that recur reproducibly [3] in response to low levels of exposure [4] to multiple unrelated chemicals and [5] improve or resolve when incitants are removed) are still unrefuted in published literature. Along with a 6th criterion that we now propose adding (i.e., requiring that symptoms occur in multiple organ systems), these criteria are all commonly encompassed by research definitions of MCS. Nonetheless, their standardized use in clinical settings is still lacking, long overdue, and greatly needed--especially in light of government studies in the United States, United Kingdom, and Canada that revealed 2-4 times as many cases of chemical sensitivity among Gulf War veterans than undeployed controls. In addition, state health department surveys of civilians in New Mexico and California showed that 2-6%, respectively, already had been diagnosed with MCS and that 16% of the civilians reported an "unusual sensitivity" to common everyday chemicals. Given this high prevalence, as well as the 1994 consensus of the American Lung Association, American Medical Association, U.S. Environmental Protection Agency, and the U.S. Consumer Product Safety Commission that "complaints [of MCS] should not be dismissed as psychogenic, and a thorough workup is essential," we recommend that MCS be formally diagnosed--in addition to any other disorders that may be present--in all cases in which the 6 aforementioned consensus criteria are met and no single other organic disorder (e.g., mastocytosis) can account for all the signs and symptoms associated with chemical exposure. The millions of civilians and tens of thousands of Gulf War veterans who

  1. International comparison of criteria for evaluating sensitization of PRTR-designated chemical substances.

    Science.gov (United States)

    Murakami, Tomoe; Oyama, Tsunehiro; Isse, Toyohi; Ogawa, Masanori; Sugie, Takuya; Kawamoto, Toshihiro

    2007-03-01

    In this study, we aim to compare the criteria for sensitizers among national organizations in various countries and international organizations, and to specify whether each Pollutant Release and Transfer Register (PRTR)-designated chemical substance is a sensitizer by each organization. The definition of sensitizing chemicals and the designation of respective sensitizers according to the PRTR law, Japan Society for Occupational Health (JSOH), American Conference of Governmental Industrial Hygienists (ACGIH), European Union (EU), and Deutsche Forschungsgemeinshaft (DFG) were studied. Of the 435 PRTR-designated chemical substances, 15 are listed as sensitizers according to the PRTR law, 16 as sensitizers of the airway and 21 as sensitizers of the skin by JSOH, 12 as sensitizers (no discrimination) by ACGIH, 19 (airway) and 85 (skin) by EU, and 15 (airway) and 43 (skin) by DFG. Only 9 substances were designated as sensitizers by all these organizations. The variation in the designation of sensitizers is accounted for by the differences in the classification criteria and grouping of chemical substances. JSOH limits the definition of sensitizers to substances that induce allergic reactions in humans and uses only human data. Other organizations utilize not only human evidence but also appropriate animal tests. In addition, EU designates an isocyanate as a sensitizer except those for which there is evidence showing that they do not cause respiratory sensitivity. The worldwide enforcement of the globally harmonized system (GHS) of classification and labeling of chemicals could promote not only the consistent designation of sensitizers among national and international organizations, but also the development of testing guidelines and classification criteria for mixtures.

  2. Development of an in vitro dendritic cell-based test for skin sensitizer identification.

    Science.gov (United States)

    Neves, Bruno Miguel; Rosa, Susana Carvalho; Martins, João Demétrio; Silva, Ana; Gonçalo, Margarida; Lopes, Maria Celeste; Cruz, Maria Teresa

    2013-03-18

    The sensitizing potential of chemicals is currently assessed using animal models. However, ethical and economic concerns and the recent European legislative framework triggered intensive research efforts in the development and validation of alternative methods. Therefore, the aim of this study was to develop an in vitro predictive test based on the analysis and integration of gene expression and intracellular signaling profiles of chemical-exposed skin-derived dendritic cells. Cells were treated with four known sensitizers and two nonsensitizers, and the effects on the expression of 20 candidate genes and the activation of MAPK, PI3K/Akt, and NF-κB signaling pathways were analyzed by real-time reverse transcription polymerase chain reaction and Western blotting, respectively. Genes Trxr1, Hmox1, Nqo1, and Cxcl10 and the p38 MAPK and JNK signaling pathways were identified as good predictor variables and used to construct a dichotomous classifier. For validation of the model, 12 new chemicals were then analyzed in a blind assay, and from these, 11 were correctly classified. Considering the total of 18 compounds tested here, 17 were correctly classified, representing a concordance of 94%, with a sensitivity of 92% (12 of 13 sensitizers identified) and a specificity of 100% (5 of 5 nonsensitizers identified). Additionally, we tested the ability of our model to discriminate sensitizers from nonallergenic but immunogenic compounds such as lipopolysaccharide (LPS). LPS was correctly classified as a nonsensitizer. Overall, our results indicate that the analysis of proposed gene and signaling pathway signatures in a mouse fetal skin-derived dendritic cell line represents a valuable model to be integrated in a future in vitro test platform.

  3. State of the art in non-animal approaches for skin sensitization testing: from individual test methods towards testing strategies.

    Science.gov (United States)

    Ezendam, Janine; Braakhuis, Hedwig M; Vandebriel, Rob J

    2016-12-01

    estimate of the potency sub-category of a skin sensitizer as well, but these approaches need further independent evaluation with a new dataset of chemicals. To conclude, this update shows that the field of non-animal approaches for skin sensitization has evolved greatly in recent years and that it is possible to predict skin sensitization hazard without animal testing.

  4. Filling the concept with data: integrating data from different in vitro and in silico assays on skin sensitizers to explore the battery approach for animal-free skin sensitization testing.

    Science.gov (United States)

    Natsch, Andreas; Emter, Roger; Ellis, Graham

    2009-01-01

    Tests for skin sensitization are required prior to the market launch of new cosmetic ingredients. Significant efforts are made to replace the current animal tests. It is widely recognized that this cannot be accomplished with a single in vitro test, but that rather the integration of results from different in vitro and in silico assays will be needed for the prediction of the skin sensitization potential of chemicals. This has been proposed as a theoretical scheme so far, but no attempts have been made to use experimental data to prove the validity of this concept. Here we thus try for the first time to fill this widely cited concept with data. To this aim, we integrate and report both novel and literature data on 116 chemicals of known skin sensitization potential on the following parameters: (1) peptide reactivity as a surrogate for protein binding, (2) induction of antioxidant/electrophile responsive element dependent luciferase activity as a cell-based assay; (3) Tissue Metabolism Simulator skin sensitization model in silico prediction; and (4) calculated octanol-water partition coefficient. The results of the in vitro assays were scaled into five classes from 0 to 4 to give an in vitro score and compared to the local lymph node assay (LLNA) data, which were also scaled from 0 to 4 (nonsensitizer/weak/moderate/strong/extreme). Different ways of evaluating these data have been assessed to rate the hazard of chemicals (Cooper statistics) and to also scale their potency. With the optimized model an overall accuracy for predicting sensitizers of 87.9% was obtained. There is a linear correlation between the LLNA score and the in vitro score. However, the correlation needs further improvement as there is still a relatively high variation in the in vitro score between chemicals belonging to the same sensitization potency class.

  5. Skin Sensitive Difference of Human Body Sections under Clothing --Comparative Judging of Body Sections' Cold Sensitivity Sequence

    Institute of Scientific and Technical Information of China (English)

    LI Jun; WANG Yun-yi; WU Hai-yan

    2005-01-01

    Skin sensitive difference of human body sections under clothing is the theoretic foundation of thermal insulation clothing design. By a new psychological & physical researching method, the subjective psychological perception of human body sections affected by the same cold stimulus are studied, and with Thurstone comparative judgement the main human body sections' cold sensitivity sequences are obtained. Furthermore the physiological causes for skin sensitive difference of human body sections under clothing are suggested.

  6. Skin sensitization risk assessment model using artificial neural network analysis of data from multiple in vitro assays.

    Science.gov (United States)

    Tsujita-Inoue, Kyoko; Hirota, Morihiko; Ashikaga, Takao; Atobe, Tomomi; Kouzuki, Hirokazu; Aiba, Setsuya

    2014-06-01

    The sensitizing potential of chemicals is usually identified and characterized using in vivo methods such as the murine local lymph node assay (LLNA). Due to regulatory constraints and ethical concerns, alternatives to animal testing are needed to predict skin sensitization potential of chemicals. For this purpose, combined evaluation using multiple in vitro and in silico parameters that reflect different aspects of the sensitization process seems promising. We previously reported that LLNA thresholds could be well predicted by using an artificial neural network (ANN) model, designated iSENS ver.1 (integrating in vitro sensitization tests version 1), to analyze data obtained from two in vitro tests: the human Cell Line Activation Test (h-CLAT) and the SH test. Here, we present a more advanced ANN model, iSENS ver.2, which additionally utilizes the results of antioxidant response element (ARE) assay and the octanol-water partition coefficient (LogP, reflecting lipid solubility and skin absorption). We found a good correlation between predicted LLNA thresholds calculated by iSENS ver.2 and reported values. The predictive performance of iSENS ver.2 was superior to that of iSENS ver.1. We conclude that ANN analysis of data from multiple in vitro assays is a useful approach for risk assessment of chemicals for skin sensitization.

  7. Discrimination of skin sensitizers from non-sensitizers by interleukin-1α and interleukin-6 production on cultured human keratinocytes.

    Science.gov (United States)

    Jung, Daun; Che, Jeong-Hwan; Lim, Kyung-Min; Chun, Young-Jin; Heo, Yong; Seok, Seung Hyeok

    2016-09-01

    In vitro testing methods for classifying sensitizers could be valuable alternatives to in vivo sensitization testing using animal models, such as the murine local lymph node assay (LLNA) and the guinea pig maximization test (GMT), but there remains a need for in vitro methods that are more accurate and simpler to distinguish skin sensitizers from non-sensitizers. Thus, the aim of our study was to establish an in vitro assay as a screening tool for detecting skin sensitizers using the human keratinocyte cell line, HaCaT. HaCaT cells were exposed to 16 relevant skin sensitizers and 6 skin non-sensitizers. The highest dose used was the dose causing 75% cell viability (CV75) that we determined by an MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. The levels of extracellular production of interleukin-1α (IL-1α) and IL-6 were measured. The sensitivity of IL-1α was 63%, specificity was 83% and accuracy was 68%. In the case of IL-6, sensitivity: 69%, specificity: 83% and accuracy: 73%. Thus, this study suggests that measuring extracellular production of pro-inflammatory cytokines IL-1α and IL-6 by human HaCaT cells may potentially classify skin sensitizers from non-sensitizers. Copyright © 2015 John Wiley & Sons, Ltd.

  8. A genomic biomarker signature can predict skin sensitizers using a cell-based in vitro alternative to animal tests

    Directory of Open Access Journals (Sweden)

    Albrekt Ann-Sofie

    2011-08-01

    Full Text Available Abstract Background Allergic contact dermatitis is an inflammatory skin disease that affects a significant proportion of the population. This disease is caused by an adverse immune response towards chemical haptens, and leads to a substantial economic burden for society. Current test of sensitizing chemicals rely on animal experimentation. New legislations on the registration and use of chemicals within pharmaceutical and cosmetic industries have stimulated significant research efforts to develop alternative, human cell-based assays for the prediction of sensitization. The aim is to replace animal experiments with in vitro tests displaying a higher predictive power. Results We have developed a novel cell-based assay for the prediction of sensitizing chemicals. By analyzing the transcriptome of the human cell line MUTZ-3 after 24 h stimulation, using 20 different sensitizing chemicals, 20 non-sensitizing chemicals and vehicle controls, we have identified a biomarker signature of 200 genes with potent discriminatory ability. Using a Support Vector Machine for supervised classification, the prediction performance of the assay revealed an area under the ROC curve of 0.98. In addition, categorizing the chemicals according to the LLNA assay, this gene signature could also predict sensitizing potency. The identified markers are involved in biological pathways with immunological relevant functions, which can shed light on the process of human sensitization. Conclusions A gene signature predicting sensitization, using a human cell line in vitro, has been identified. This simple and robust cell-based assay has the potential to completely replace or drastically reduce the utilization of test systems based on experimental animals. Being based on human biology, the assay is proposed to be more accurate for predicting sensitization in humans, than the traditional animal-based tests.

  9. Brief analysis of causes of sensitive skin and advances in evaluation of anti-allergic activity of cosmetic products.

    Science.gov (United States)

    Fan, L; He, C; Jiang, L; Bi, Y; Dong, Y; Jia, Y

    2016-04-01

    This review focuses on the causes of sensitive skin and elaborates on the relationship between skin sensitivity and skin irritations and allergies, which has puzzled cosmetologists. Here, an overview is presented of the research on active ingredients in cosmetic products for sensitive skin (anti-sensitive ingredients), which is followed by a discussion of their experimental efficacy. Moreover, several evaluation methods for the efficacy of anti-sensitive ingredients are classified and summarized. Through this review, we aim to provide the cosmetic industry with a better understanding of sensitive skin, which could in turn provide some theoretical guidance to the research on targeted cosmetic products.

  10. Skin irritants and contact sensitizers induce Langerhans cell migration and maturation at irritant concentration

    NARCIS (Netherlands)

    Jacobs, J.J.L.; Lehé, C.L.; Hasegawa, H.; Elliott, G.R.; Das, P.K.

    2006-01-01

    Skin irritants and contact allergens reduce the number of Langerhans cells (LCs). It has been assumed that this reduction is due their migration to the draining lymph node (LN) for initiating immune sensitization in a host. Skin irritation, however, as opposed to contact allergy is not considered to

  11. Reactive skin decontamination lotion (RSDL) for the decontamination of chemical warfare agent (CWA) dermal exposure.

    Science.gov (United States)

    Schwartz, M D; Hurst, C G; Kirk, M A; Reedy, S J D; Braue, E H

    2012-08-01

    Rapid decontamination of the skin is the single most important action to prevent dermal absorption of chemical contaminants in persons exposed to chemical warfare agents (CWA) and toxic industrial chemicals (TICs) as a result of accidental or intentional release. Chemicals on the skin may be removed by mechanical means through the use of dry sorbents or water. Recent interest in decontamination systems which both partition contaminants away from the skin and actively neutralize the chemical has led to the development of several reactive decontamination solutions. This article will review the recently FDA-approved Reactive Skin Decontamination Lotion (RSDL) and will summarize the toxicity and efficacy studies conducted to date. Evidence of RSDL's superior performance against vesicant and organophosphorus chemical warfare agents compared to water, bleach, and dry sorbents, suggests that RSDL may have a role in mass human exposure chemical decontamination in both the military and civilian arenas.

  12. A skin sensitization risk assessment approach for evaluation of new ingredients and products.

    Science.gov (United States)

    Gerberick, G F; Robinson, M K

    2000-06-01

    Skin sensitization risk assessment of new ingredients or products is critical before their introduction into the marketplace. The risk assessment process described in this article involves evaluation of skin sensitization hazard, consideration of all potential human exposures, comparative ingredient/product benchmarking, and, when appropriate, the management of the risk. In this article, a risk assessment process is reviewed along with a description of the risk assessment tools that are employed for evaluating a new ingredient or product. The basic process we use for evaluating the skin sensitization risk of a new product or ingredient is considered a no effect/safety factor approach. The tools used for conducting a risk assessment include structure activity relationship analysis, exposure assessment, preclinical testing (e.g., local lymph node assay [LNNA]) and clinical testing (e.g., human repeat insult patch testing [HRIPT]). The skin sensitization risk assessment process described in this paper has been used successfully for many years for the safe introduction of new products into the marketplace. This process is dynamic--it can be applied to a diversity of product categories (e.g., shampoo, transdermal drug). In summary, the skin sensitization risk assessment process described in this article allows one to carefully assess the skin sensitization potential of a new ingredient or product so that it can be safely introduced into the marketplace.

  13. Chemical peels for melasma in dark-skinned patients

    Directory of Open Access Journals (Sweden)

    Rashmi Sarkar

    2012-01-01

    Full Text Available Melasma is a common disorder of hyperpigmentation, which has a severe impact on the quality of life. Inspite of tremendous research, the treatment remains frustrating both to the patient and the treating physician. Dark skin types (Fitzpatrick types IV to VI are especially difficult to treat owing to the increased risk of post-inflammatory hyperpigmentation (PIH. The treatment ranges from a variety of easily applied topical therapies to agents like lasers and chemical peels. Peels are a well-known modality of treatment for melasma, having shown promising results in many clinical trials. However, in darker races, the choice of the peeling agent becomes relatively limited; so, there is the need for priming agents and additional maintenance peels. Although a number of new agents have come up, there is little published evidence supporting their use in day-to -day practice. The traditional glycolic peels prove to be the best both in terms of safety as well as efficacy. Lactic acid peels being relatively inexpensive and having shown equally good results in a few studies, definitely need further experimentation. We also recommend the use of a new peeling agent, the easy phytic solution, which does not require neutralisation unlike the traditional alpha-hydroxy peels. The choice of peeling agent, the peel concentration as well as the frequency and duration of peels are all important to achieve optimum results.

  14. Chemical Peels for Melasma in Dark-Skinned Patients

    Science.gov (United States)

    Sarkar, Rashmi; Bansal, Shuchi; Garg, Vijay K

    2012-01-01

    Melasma is a common disorder of hyperpigmentation, which has a severe impact on the quality of life. Inspite of tremendous research, the treatment remains frustrating both to the patient and the treating physician. Dark skin types (Fitzpatrick types IV to VI) are especially difficult to treat owing to the increased risk of post-inflammatory hyperpigmentation (PIH). The treatment ranges from a variety of easily applied topical therapies to agents like lasers and chemical peels. Peels are a well-known modality of treatment for melasma, having shown promising results in many clinical trials. However, in darker races, the choice of the peeling agent becomes relatively limited; so, there is the need for priming agents and additional maintenance peels. Although a number of new agents have come up, there is little published evidence supporting their use in day-to -day practice. The traditional glycolic peels prove to be the best both in terms of safety as well as efficacy. Lactic acid peels being relatively inexpensive and having shown equally good results in a few studies, definitely need further experimentation. We also recommend the use of a new peeling agent, the easy phytic solution, which does not require neutralisation unlike the traditional alpha-hydroxy peels. The choice of peeling agent, the peel concentration as well as the frequency and duration of peels are all important to achieve optimum results. PMID:23378706

  15. Multiple chemical sensitivity, en veldefineret lidelse?

    DEFF Research Database (Denmark)

    Kolstad, Henrik A.; Silberschmidt, Martin; Nielsen, Jesper Bo

    2006-01-01

    , even though a number of theories have been proposed. The authors of this review conclude that this is a functional condition. These patients need information and treatment in accordance with this fact. Instead of being advised how to avoid exposure to chemicals, they should be properly trained...... in appropriate confrontation with the chemicals encountered in everyday life....

  16. Multiple chemical sensitivity, en veldefineret lidelse?

    DEFF Research Database (Denmark)

    Kolstad, Henrik A; Silberschmidt, Martin; Nielsen, Jesper Bo

    2006-01-01

    mechanisms, even though a number of theories have been proposed. The authors of this review conclude that this is a functional condition. These patients need information and treatment in accordance with this fact. Instead of being advised how to avoid exposure to chemicals, they should be properly trained...... in appropriate confrontation with the chemicals encountered in everyday life....

  17. Touch perceptions across skin sites: differences between sensitivity, direction discrimination and pleasantness

    Directory of Open Access Journals (Sweden)

    Rochelle eAckerley

    2014-02-01

    Full Text Available Human skin is innervated with different tactile afferents over the body, which are found at varying densities. We investigate how the relationships between tactile pleasantness, sensitivity and discrimination differ across the skin. Tactile pleasantness was assessed by stroking a soft brush over the skin, using five velocities (0.3, 1, 3, 10, 30 cm s-1, known to differentiate hedonic touch, and pleasantness ratings were gained. The ratings velocity-profile is known to correlate with firing in unmyelinated C-tactile afferents. Tactile sensitivity thresholds were determined using monofilament force detection and the tactile discrimination level was obtained in the direction discrimination of a moving probe; both tasks readily activate myelinated touch receptors. Perceptions were measured over five skin sites: forehead, arm, palm, thigh and shin. The assessment of tactile pleasantness over the skin resulted in a preference for the middle velocities (1-10 cm s-1, where higher ratings were gained compared to the slowest and fastest velocities. This preference in tactile pleasantness was found across all the skin sites, apart from at the palm, where no decrease in pleasantness for the faster stroking velocities was seen. We find that tactile sensitivity and discrimination vary across the skin, where the forehead and palm show increased acuity. Tactile sensitivity and discrimination levels also correlated significantly, although the tactile acuity did not relate to the perceived pleasantness of touch. Tactile pleasantness varied in a subtle way across skin sites, where the middle velocities were always rated as the most pleasant, but the ratings at hairy skin sites were more receptive to changes in stroking velocity. We postulate that although the mechanoreceptive afferent physiology may be different over the skin, the perception of pleasant touch can be interpreted using all of the available incoming somatosensory information in combination with

  18. Gene expression in the skin of dogs sensitized to the house dust mite Dermatophagoides farinae.

    Science.gov (United States)

    Schamber, Paz; Schwab-Richards, Rachel; Bauersachs, Stefan; Mueller, Ralf S

    2014-10-01

    Atopic dermatitis is a multifactorial allergic skin disease in humans and dogs. Genetic predisposition, immunologic hyperreactivity, a defective skin barrier, and environmental factors play a role in its pathogenesis. The aim of this study was to analyze gene expression in the skin of dogs sensitized to house dust mite antigens. Skin biopsy samples were collected from six sensitized and six nonsensitized Beagle dogs before and 6 hr and 24 hr after challenge using skin patches with allergen or saline as a negative control. Transcriptome analysis was performed by the use of DNA microarrays and expression of selected genes was validated by quantitative real-time RT-PCR. Expression data were compared between groups (unpaired design). After 24 hr, 597 differentially expressed genes were detected, 361 with higher and 226 with lower mRNA concentrations in allergen-treated skin of sensitized dogs compared with their saline-treated skin and compared with the control specimens. Functional annotation clustering and pathway- and co-citation analysis showed that the genes with increased expression were involved in inflammation, wound healing, and immune response. In contrast, genes with decreased expression in sensitized dogs were associated with differentiation and barrier function of the skin. Because the sensitized dogs did not show differences in the untreated skin compared with controls, inflammation after allergen patch test probably led to a decrease in the expression of genes important for barrier formation. Our results further confirm the similar pathophysiology of human and canine atopic dermatitis and revealed genes previously not known to be involved in canine atopic dermatitis.

  19. STUDIES ON THE SENSITIZATION OF ANIMALS WITH SIMPLE CHEMICAL COMPOUNDS

    Science.gov (United States)

    Landsteiner, K.; Di Somma, A. A.

    1940-01-01

    Sensitization of guinea pigs to picric acid was obtained by application of oil solutions to the skin, preferably on inflamed sites or by treatment with a compound of picric acid with n-butyl-p-aminobenzoate. The lesions obtained in sensitive animals on superficial administration bore resemblance to human eczema. It seems probable that picric acid sensitization is an instance where a substance does not sensitize directly but after conversion into a more reactive compound, a principle which should be of wider application to instances where the original substance does not readily form conjugates. PMID:19871030

  20. Sensitive Diagnostics for Chemically Reacting Flows

    KAUST Repository

    Farooq, Aamir

    2015-11-02

    This talk will feature latest diagnostic developments for sensitive detection of gas temperature and important combustion species. Advanced optical strategies, such as intrapulse chirping, wavelength modulation, and cavity ringdown are employed.

  1. Bragg grating chemical sensor with hydrogel as sensitive element

    Institute of Scientific and Technical Information of China (English)

    Xiaomei Liu(刘小梅); Shilie Zheng(郑史烈); Xianmin Zhang(章献民); Jun Cong(丛军); Kangsheng Chen(陈抗生); Jian Xu(徐坚)

    2004-01-01

    A novel fiber Bragg grating (FBG) based chemical sensor using hydrogel, a swellable polymer, as sensitive element is demonstrated. The sensing mechanism relies on the shift of Bragg wavelength due to the stress resulted from volume change of sensitive swellable hydrogel responding to the change of external environment. A polyacrylamide hydrogel fiber grating chemical sensor is made, and the experiments on its sensitivity to the salinity are performed. The sensitivity is low due to the less stress from the shrinking or swelling of hydrogels. Reducing the cross diameter of the grating through etching with hydrofluoric acid can greatly improve the sensitivity of the sensor.

  2. Intense pain influences the cortical processing of visual stimuli projected onto the sensitized skin

    Science.gov (United States)

    Torta, DM; Van Den Broeke, EN; Filbrich, L; Jacob, B; Lambert, J; Mouraux, A

    2017-01-01

    Sensitization is a form of implicit learning produced by the exposure to a harmful stimulus. In humans and other mammals, sensitization following skin injury increases the responsiveness of peripheral nociceptors, and enhances the synaptic transmission of nociceptive input in the central nervous system (CNS). Here, we show that sensitization-related changes in the CNS are not restricted to nociceptive pathways and, instead, also affect other sensory modalities, especially if that modality conveys information relevant for the sensitized body part. Specifically, we show that after sensitizing the forearm using high-frequency electrical stimulation of the skin (HFS), visual stimuli projected onto the sensitized forearm elicit significantly enhanced brain responses. Whereas mechanical hyperalgesia was present both 20 and 45 minutes after HFS, the enhanced responsiveness to visual stimuli was present only 20 minutes after HFS. Taken together, our results indicate that sensitization involves both nociceptive-specific and multimodal mechanisms, having distinct time courses. PMID:28030473

  3. Skin exposure promotes a Th2 - dependent sensitization to peanut allergens

    Science.gov (United States)

    Sensitization to foods often occurs in infancy without known prior oral exposure, which suggests that alternative routes of exposure contribute to food allergy. We hypothesized that peanut activates innate immune pathways in the skin that promote sensitization. We tested this hypothesis by topical...

  4. Water decontamination of chemical skin/eye splashes: a critical review.

    Science.gov (United States)

    Hall, Alan H; Maibach, Howard I

    2006-01-01

    Skin/eye chemical splashes are a significant workplace problem. Initial water decontamination is usually recommended, but there are few well-conducted experimental animal and human studies of efficacy. An extensive review of the literature and other available information sources was performed to define the scope of the problem and critically review the evidence for water decontamination efficacy. Although water decontamination can decrease the severity of chemical skin/eye burns, it cannot completely prevent them. An ideal replacement decontamination solution would be sterile, nontoxic, chelating, polyvalent, amphoteric, and slightly hypertonic to retard skin or corneal penetration of the chemical.

  5. SKIN SENSITIZATION AND ALLERGIC CONTACT DERMATITIS (BASIC COURSE): THE GLOBAL REGULATORY ENVIRONMENT - CONTINUING EDUCATION COURSE; 1 OF 4 SPEAKERS FOR AN SOT BASIC COURSE

    Science.gov (United States)

    New regulations have emerged in recent years giving guidance on how best to conduct skin sensitization testing on new chemical entities. For example, recently The Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM) in the U.S. and the European Ce...

  6. Selective skin sensitivity changes and sensory reweighting following short-duration space flight.

    Science.gov (United States)

    Lowrey, Catherine R; Perry, Stephen D; Strzalkowski, Nicholas D J; Williams, David R; Wood, Scott J; Bent, Leah R

    2014-03-15

    Skin sensory input from the foot soles is coupled with vestibular input to facilitate body orientation in a gravitational environment. Anecdotal observations suggest that foot sole skin becomes hypersensitive following space flight. The veritable level of skin sensitivity and its impact on postural disequilibrium observed post space flight have not been documented. Skin sensitivity of astronauts (n = 11) was measured as vibration perception at the great toe, fifth metatarsal and heel. Frequencies targeted four classes of receptors: 3 and 25 Hz for slow-adapting (SA) receptors and 60 and 250 Hz for fast-adapting (FA) receptors. Data were collected pre- and post-space flight. We hypothesized that skin sensitivity would increase post-space flight and correlate to balance measures. Decreased skin sensitivity was found on landing day at 3 and 25 Hz on the great toe. Hypersensitivity was found for a subset of astronauts (n = 6) with significantly increased sensitivity to 250 Hz at the heel. This subset displayed a greater reduction in computerized dynamic posturography (CDP) equilibrium (EQ) scores (-54%) on landing vs. non-hypersensitive participants (-11%). Observed hyposensitivity of SA (pressure) receptors may indicate a strategy to reduce pressure input during periods of unloading. Hypersensitivity of FAs coupled with reduced EQ scores may reflect targeted sensory reweighting. Altered gravito-inertial environments reduce vestibular function in balance control which may trigger increased weighting of FAs (that signal foot contact, slips). Understanding modulations to skin sensitivity has translational implications for mitigating postural disequilibrium following space flight and for on-Earth preventative strategies for imbalance in older adults.

  7. A magneto-sensitive skin for robots in space

    Science.gov (United States)

    Chauhan, D. S.; Dehoff, P. H.

    1991-01-01

    The development of a robot arm proximity sensing skin that can sense intruding objects is described. The purpose of the sensor would be to prevent the robot from colliding with objects in space including human beings. Eventually a tri-mode system in envisioned including proximity, tactile, and thermal. To date the primary emphasis was on the proximity sensor which evolved from one based on magneto-inductive principles to the current design which is based on a capacitive-reflector system. The capacitive sensing element, backed by a reflector driven at the same voltage and in phase with the sensor, is used to reflect field lines away from the grounded robot toward the intruding object. This results in an increased sensing range of up to 12 in. with the reflector on compared with only 1 in. with it off. It is believed that this design advances the state-of-the-art in capacitive sensor performance.

  8. Three-dimensional conformal graphene microstructure for flexible and highly sensitive electronic skin

    Science.gov (United States)

    Yang, Jun; Ran, Qincui; Wei, Dapeng; Sun, Tai; Yu, Leyong; Song, Xuefen; Pu, Lichun; Shi, Haofei; Du, Chunlei

    2017-03-01

    We demonstrate a highly stretchable electronic skin (E-skin) based on the facile combination of microstructured graphene nanowalls (GNWs) and a polydimethylsiloxane (PDMS) substrate. The microstructure of the GNWs was endowed by conformally growing them on the unpolished silicon wafer without the aid of nanofabrication technology. Then a stamping transfer method was used to replicate the micropattern of the unpolished silicon wafer. Due to the large contact interface between the 3D graphene network and the PDMS, this type of E-skin worked under a stretching ratio of nearly 100%, and showed excellent mechanical strength and high sensitivity, with a change in relative resistance of up to 6500% and a gauge factor of 65.9 at 99.64% strain. Furthermore, the E-skin exhibited an obvious highly sensitive response to joint movement, eye movement and sound vibration, demonstrating broad potential applications in healthcare, body monitoring and wearable devices.

  9. Further development of an in vitro model for studying the penetration of chemicals through compromised skin.

    Science.gov (United States)

    Davies, Diane J; Heylings, Jon R; Gayes, Heather; McCarthy, Timothy J; Mack, M Catherine

    2017-02-01

    A new in vitro model based on the electrical resistance properties of the skin barrier has been established in this laboratory. The model utilises a tape stripping procedure in dermatomed pig skin that removes a specific proportion of the stratum corneum, mimicking impaired barrier function observed in humans with damaged skin. The skin penetration and distribution of chemicals with differing physicochemical properties, namely; Benzoic acid, 3-Aminophenol, Caffeine and Sucrose has been assessed in this model. Although, skin penetration over 24h differed for each chemical, compromising the skin did not alter the shape of the time course profile, although absorption into receptor fluid was higher for each chemical. Systemic exposure (receptor fluid, epidermis and dermis), was marginally higher in compromised skin following exposure to the fast penetrant, Benzoic acid, and the slow penetrant Sucrose. The systemically available dose of 3-Aminophenol increased to a greater extent and the absorption of Caffeine was more than double in compromised skin, suggesting that Molecular Weight and Log Pow, are not the only determinants for assessing systemic exposure under these conditions. Although further investigations are required, this in vitro model may be useful for prediction of dermal route exposure under conditions where skin barrier is impaired.

  10. Studies on percutaneous penetration of chemicals - Impact of storage conditions for excised human skin.

    Science.gov (United States)

    Dennerlein, Kathrin; Schneider, Désirée; Göen, Thomas; Schaller, Karl Heinz; Drexler, Hans; Korinth, Gintautas

    2013-03-01

    According to international guidelines skin penetration experiments can be carried out using freshly excised or frozen stored skin. However, this recommendation refers to data obtained in experiments with human cadaver skin. In our study, the percutaneous penetration of the occupationally relevant chemicals anisole, cyclohexanone and 1,4-dioxane was investigated for freshly excised as well as for 4 and 30 days at -20°C stored human skin using the diffusion cell technique. As indicator for the impairment of skin barrier by freezing cholesterol dissolution was determined in the solvents in exposure chambers of diffusion cells. Considering the percutaneously penetrated amounts, the following ranking was determined: 1,4-dioxane>anisole>cyclohexanone (decline to a factor of 5.9). The differences of fluxes between freshly excised and frozen stored skin (4 and 30 days) were not significant (p>0.05). Cholesterol dissolved from the skin indicates no significant differences between freshly excised and frozen stored skin. This study shows that freezing of human skin for up to 30 days does not alter the skin barrier function and the permeability of chemicals.

  11. Carbon dioxide instantly sensitizes female yellow fever mosquitoes to human skin odours.

    Science.gov (United States)

    Dekker, Teun; Geier, Martin; Cardé, Ring T

    2005-08-01

    Female mosquitoes are noted for their ability to use odours to locate a host for a blood meal. Two sensory organs contribute to their sense of smell: the maxillary palps, which measure the level of CO2, and the antennae, which detect other host-released odours. To establish the relative importance and interactions of CO2 and other body emissions in freely flying mosquitoes, we presented female yellow fever mosquitoes Aedes aegypti L. with broad plumes of human skin odour and CO2 at natural concentrations and dilutions thereof in a wind tunnel. 3-D video-recorded flight tracks were reconstructed. Activation, flight velocity, upwind turning and source finding waned quickly as skin odours were diluted, whereas in the presence of CO2 these parameters remained unchanged over more than a 100-fold dilution from exhaled concentrations. Although mosquitoes were behaviourally less sensitive to skin odours than to CO2, their sensitivity to skin odours increased transiently by at least fivefold immediately following a brief encounter with a filament of CO2. This sensitization was reflected in flight velocity, track angle, turning rate upon entering and exiting the broad odour plume and, ultimately, in the source-finding rate. In Ae. aegypti, CO2 thus functions as a ;releaser' for a higher sensitivity and responsiveness to skin odours. The initially low responsiveness of mosquitoes to skin odours, their high sensitivity to CO2, and the sensitization of the olfactory circuitry by CO2 are ecologically relevant, because rapidly fluctuating CO2 levels reliably signal a potential host. Possible mechanisms of the instantaneous sensitization are considered.

  12. Assessment of the skin irritation potential of chemicals by using the SkinEthic reconstructed human epidermal model and the common skin irritation protocol evaluated in the ECVAM skin irritation validation study.

    Science.gov (United States)

    Kandárová, Helena; Liebsch, Manfred; Schmidt, Elisabeth; Genschow, Elke; Traue, Dieter; Spielmann, Horst; Meyer, Kirstin; Steinhoff, Claudia; Tornier, Carine; De Wever, Bart; Rosdy, Martin

    2006-08-01

    Currently, two reconstructed human skin models, EpiDerm and EPISKIN are being evaluated in an ECVAM skin irritation validation study. A common skin irritation protocol has been developed, differing only in minor technical details for the two models. A small-scale study, applying this common skin irritation protocol to the SkinEthic reconstructed human epidermis (RHE), was performed at ZEBET at the BfR, Berlin, Germany, to consider whether this protocol could be successfully transferred to another epidermal model. Twenty substances from Phase III of the ECVAM prevalidation study on skin irritation were tested with the SkinEthic RHE. After minor, model-specific adaptations for the SkinEthic RHE, almost identical results to those obtained with the EpiDerm and EPISKIN models were achieved. The overall accuracy of the method was more than 80%, indicating a reliable prediction of the skin irritation potential of the tested chemicals when compared to in vivo rabbit data. As a next step, inter laboratory reproducibility was assessed in a study conducted between ZEBET and the Department of Experimental Toxicology, Schering AG, Berlin, Germany. Six coded substances were tested in both laboratories, with three different batches of the SkinEthic model. The assay results showed good reproducibility and correct predictions of the skin irritation potential for all six test chemicals. The results obtained with the SkinEthic RHE and the common protocol were reproducible in both phases, and the overall outcome is very similar to that of earlier studies with the EPISKIN and EpiDerm models. Therefore, the SkinEthic skin irritation assay test protocol can now be evaluated in a formal "catch-up" validation study.

  13. Integrating non-animal test information into an adaptive testing strategy - skin sensitization proof of concept case.

    Science.gov (United States)

    Jaworska, Joanna; Harol, Artsiom; Kern, Petra S; Gerberick, G Frank

    2011-01-01

    There is an urgent need to develop data integration and testing strategy frameworks allowing interpretation of results from animal alternative test batteries. To this end, we developed a Bayesian Network Integrated Testing Strategy (BN ITS) with the goal to estimate skin sensitization hazard as a test case of previously developed concepts (Jaworska et al., 2010). The BN ITS combines in silico, in chemico, and in vitro data related to skin penetration, peptide reactivity, and dendritic cell activation, and guides testing strategy by Value of Information (VoI). The approach offers novel insights into testing strategies: there is no one best testing strategy, but the optimal sequence of tests depends on information at hand, and is chemical-specific. Thus, a single generic set of tests as a replacement strategy is unlikely to be most effective. BN ITS offers the possibility of evaluating the impact of generating additional data on the target information uncertainty reduction before testing is commenced.

  14. Enhanced sensitivity for hyperspectral infrared chemical detection

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, P. L. (Phillip L.); Petrin, R. R. (Roger R.); Koskelo, A. C. (Aaron C.); Quick, C. R. (Charles R.); Romero, J. J. (Jerry J.)

    2001-01-01

    The sensitivity of imaging, hyperspectral, passive remote sensors in the long-wavelength infrared (LWIR) spectral region is currently limited by the ability to achieve an accurate, time-invariant, pixel-to-pixel calibration of the elements composing the Focal Plane Array (FPA). Pursuing conventional techniques to improve the accuracy of the calibration will always be limited by the trade-off between the time required to collect calibration data of improved precision and the drift in the pixel response that occurs on a timescale comparable to the calibration time. This paper will present the results from a study of a method to circumvent these problems. Improvements in detection capability can be realized by applying a quick, repetitive dither of the field of view (FOV) of the imager (by a small angular amount), so that radiance/spectral differences between individual target areas can be measured by a single FPA pixel. By performing this difference measurement repetitively both residual differences in the pixel-to-pixel calibration and l/f detector drift noise can effectively be eliminated. In addition, variations in the atmosphere and target scene caused by the motion of the sensor platform will cause signal drifts that this technique would be able to remove. This method allows improvements in sensitivity that could potentially scale as the square root of the observation time.

  15. The pretreatment effect of chemical skin penetration enhancers in transdermal drug delivery using iontophoresis.

    Science.gov (United States)

    Choi, E H; Lee, S H; Ahn, S K; Hwang, S M

    1999-01-01

    The transdermal drug delivery (TDD) system has largely been divided into physical, biochemical and chemical methods. Recently, combinations of these methods were introduced for more effective delivery with less side effects. We performed this study to identify the effectiveness and mechanism of TDD using the physical method, 'iontophoresis', plus the chemical method, 'pretreatment with chemical enhancer'. The action sites of chemical enhancers in the stratum corneum (SC) were observed by electron microscope. We also studied whether this combined method synergistically impaired the skin barrier. To confirm the synergistic effect on skin penetration by this combined method, we measured the blood glucose level after insulin iontophoresis following a chemical enhancer pretreatment in rabbits. The results were that (1) dilatation of the intercellular lipid layers of the SC and lacunae was prominent in pretreatment with chemical enhancers inducing high transepidermal water loss (TEWL); (2) the skin barrier impairment, with repeated treatments showing an increased TEWL and also epidermal proliferation, was increased with the chemical enhancers that showed a high TEWL immediately after treatment; (3) the combination of chemical enhancer pretreatment and iontophoresis showed no synergistic impairment of the skin barrier, and (4) the chemical enhancer pretreatment with greater impairment of the skin barrier could increase the delivery of insulin by iontophoresis. The results showed that a combination of chemical enhancer pretreatment and iontophoresis could deliver drugs more effectively than iontophoresis alone. Our proposed theory is that iontophoretic drug delivery may be easier through the dilated intercellular spaces of the SC which have a lower electrical impedance following the chemical enhancer pretreatment. Because the effect and the side effects in the combination are decided by the chemical enhancer rather than iontophoresis, the development of proper chemical

  16. Multiple chemical sensitivity and idiopathic environmental intolerance (part two)

    OpenAIRE

    Watanabe, Mitsuyasu; Tonori, Hideki; Aizawa, Yoshiharu

    2003-01-01

    Multiple chemical sensitivity/idiopathic environmental intolerance (MCS/IEI) is a commonly used diagnostic term for a group of symptoms without apparent organic basis. The symptoms are characteristic of dysfunction in multiple organ systems. They wax and wane fluctuate according to exposure to low levels of chemical agents in the patient's environment, and sometimes begin after a distinct environmental change or injury such an industrial accident or chemical introduced after remodeling. Altho...

  17. Is skin penetration a determining factor in skin sensitization potential and potency? Refuting the notion of a LogKow threshold for Skin Sensitization

    Science.gov (United States)

    Summary:Background. It is widely accepted that substances that cannot penetrate through the skin will not be sensitisers. Thresholds based on relevant physicochemical parameters such as a LogKow > 1 and a MW < 500, are assumed and widely accepted as self-evident truths. Objective...

  18. A nanofiber based artificial electronic skin with high pressure sensitivity and 3D conformability.

    Science.gov (United States)

    Zhong, Weibin; Liu, Qiongzhen; Wu, Yongzhi; Wang, Yuedan; Qing, Xing; Li, Mufang; Liu, Ke; Wang, Wenwen; Wang, Dong

    2016-06-16

    Pressure sensors with 3D conformability are highly desirable components for artificial electronic skin or e-textiles that can mimic natural skin, especially for application in real-time monitoring of human physiological signals. Here, a nanofiber based electronic skin with ultra-high pressure sensitivity and 3D conformability is designed and built by interlocking two elastic patterned nanofibrous membranes. The patterned membrane is facilely prepared by casting conductive nanofiber ink into a silicon mould to form an array of semi-spheroid-like protuberances. The protuberances composed of intertwined elastic POE nanofibers and PPy@PVA-co-PE nanofibers afford a tunable effective elastic modulus that is capable of capturing varied strains and stresses, thereby contributing to a high sensitivity for pressure sensing. This electronic skin-like sensor demonstrates an ultra-high sensitivity (1.24 kPa(-1)) below 150 Pa with a detection limit as low as about 1.3 Pa. The pixelated sensor array and a RGB-LED light are then assembled into a circuit and show a feasibility for visual detection of spatial pressure. Furthermore, a nanofiber based proof-of-concept wireless pressure sensor with a bluetooth module as a signal transmitter is proposed and has demonstrated great promise for wireless monitoring of human physiological signals, indicating a potential for large scale wearable electronic devices or e-skin.

  19. An Animal Model of Trichloroethylene-Induced Skin Sensitization in BALB/c Mice.

    Science.gov (United States)

    Wang, Hui; Zhang, Jia-xiang; Li, Shu-long; Wang, Feng; Zha, Wan-sheng; Shen, Tong; Wu, Changhao; Zhu, Qi-xing

    2015-01-01

    Trichloroethylene (TCE) is a major occupational hazard and environmental contaminant that can cause multisystem disorders in the form of occupational medicamentosa-like dermatitis. Development of dermatitis involves several proinflammatory cytokines, but their role in TCE-mediated dermatitis has not been examined in a well-defined experimental model. In addition, few animal models of TCE sensitization are available, and the current guinea pig model has apparent limitations. This study aimed to establish a model of TCE-induced skin sensitization in BALB/c mice and to examine the role of several key inflammatory cytokines on TCE sensitization. The sensitization rate of dorsal painted group was 38.3%. Skin edema and erythema occurred in TCE-sensitized groups, as seen in 2,4-dinitrochlorobenzene (DNCB) positive control. Trichloroethylene sensitization-positive (dermatitis [+]) group exhibited increased thickness of epidermis, inflammatory cell infiltration, swelling, and necrosis in dermis and around hair follicle, but ear painted group did not show these histological changes. The concentrations of serum proinflammatory cytokines including tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and interleukin (IL)-2 were significantly increased in 24, 48, and 72 hours dermatitis [+] groups treated with TCE and peaked at 72 hours. Deposition of TNF-α, IFN-γ, and IL-2 into the skin tissue was also revealed by immunohistochemistry. We have established a new animal model of skin sensitization induced by repeated TCE stimulations, and we provide the first evidence that key proinflammatory cytokines including TNF-α, IFN-γ, and IL-2 play an important role in the process of TCE sensitization.

  20. What happens after the activation of ascaridole? Reactive compounds and their implications for skin sensitization

    Science.gov (United States)

    To replace animal testing and to improve the prediction of skin sensitization, significant attention has been directed to the use of alternative methods. Along with induction of Nrf2 target gene and upregulation of CD86 and C54 markers, the direct peptide reactivity assay (DPRA), the regulatory agen...

  1. Differential effects of chemical irritants in rabbit and human skin organ cultures

    NARCIS (Netherlands)

    Sandt, J.J.M. van de; Rutten, A.A.J.J.L.

    1995-01-01

    The toxicity of well known irritants was investigated in rabbit and human skin organ cultures. Test chemicals were selected from various categories of irritants and included both water-soluble and water-insoluble compounds. Using a highly standardized protocol, test chemicals were applied topically

  2. Polyvalent type IV sensitizations to multiple fragrances and a skin protection cream in a metal worker.

    Science.gov (United States)

    Tanko, Zita; Shab, Arna; Diepgen, Thomas Ludwig; Weisshaar, Elke

    2009-06-01

    Fragrances are very common in everyday products. A metalworker with chronic hand eczema and previously diagnosed type IV sensitizations to epoxy resin, balsam of Peru, fragrance mix and fragrance mix II was diagnosed with additional type IV sensitizations to geraniol, hydroxycitronellal, lilial, tree moss, oak moss absolute, citral, citronellol, farnesol, Lyral, fragrance mix II and fragrance mix (with sorbitan sesquioleate). In addition, a type IV sensitization to the skin protection cream containing geraniol and citronellol used at the workplace was detected, and deemed occupationally relevant in this case. The patient could have had contact to fragrances through private use of cosmetics and detergents. On the other hand, the fragrance-containing skin protection cream supports occupational exposure. This case report demonstrates that fragrance contact allergy has to be searched for and clarified individually, which requires a thorough history and a detailed analysis of the work place.

  3. Are basophil histamine release and high affinity IgE receptor expression involved in asymptomatic skin sensitization?

    DEFF Research Database (Denmark)

    Jensen, Bettina Margrethe; Assing, K; Jensen, Lone Hummelshøj;

    2006-01-01

    Immunoglobulin (Ig)E-sensitized persons with positive skin prick test, but no allergy symptoms, are classified as being asymptomatic skin sensitized (AS). The allergic type 1 disease is dependant on IgE binding to the high affinity IgE-receptor (FcepsilonRI) expressed on basophils and mast cells...

  4. Grass pollen symptoms interfere with the recollection of birch pollen symptoms - a prospective study of suspected, asymptomatic skin sensitization

    DEFF Research Database (Denmark)

    Assing, K; Bodtger, U; Poulsen, Lars K.

    2007-01-01

    Asymptomatic skin sensitization (AS) is a risk factor for the development of allergic symptoms. A meticulous definition of this condition requires a systematic assessment of clinical symptoms before inclusion.......Asymptomatic skin sensitization (AS) is a risk factor for the development of allergic symptoms. A meticulous definition of this condition requires a systematic assessment of clinical symptoms before inclusion....

  5. Cooling-sensitive TRPM8 is thermostat of skin temperature against cooling.

    Directory of Open Access Journals (Sweden)

    Koji Tajino

    Full Text Available We have shown that cutaneous cooling-sensitive receptors can work as thermostats of skin temperature against cooling. However, molecule of the thermostat is not known. Here, we studied whether cooling-sensitive TRPM8 channels act as thermostats. TRPM8 in HEK293 cells generated output (y when temperature (T was below threshold of 28.4°C. Output (y is given by two equations: At T >28.4°C, y = 0; At T <28.4°C, y  =  -k(T - 28.4°C. These equations show that TRPM8 is directional comparator to elicits output (y depending on negative value of thermal difference (ΔT  =  T - 28.4°C. If negative ΔT-dependent output of TRPM8 in the skin induces responses to warm the skin for minimizing ΔT recursively, TRPM8 acts as thermostats against cooling. With TRPM8-deficient mice, we explored whether TRPM8 induces responses to warm the skin against cooling. In behavioral regulation, when room temperature was 10°C, TRPM8 induced behavior to move to heated floor (35°C for warming the sole skin. In autonomic regulation, TRPM8 induced activities of thermogenic brown adipose tissue (BAT against cooling. When menthol was applied to the whole trunk skin at neutral room temperature (27°C, TRPM8 induced a rise in core temperature, which warmed the trunk skin slightly. In contrast, when room was cooled from 27 to 10°C, TRPM8 induced a small rise in core temperature, but skin temperature was severely reduced in both TRPM8-deficient and wild-type mice by a large heat leak to the surroundings. This shows that TRPM8-driven endothermic system is less effective for maintenance of skin temperature against cooling. In conclusion, we found that TRPM8 is molecule of thermostat of skin temperature against cooling.

  6. Genetic susceptibility factors for multiple chemical sensitivity revisited

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Berg; Linneberg, Allan; Andersen, Charlotte Brasch;

    2010-01-01

    Multiple chemical sensitivity (MCS) is characterised by adverse effects due to exposure to low levels of chemical substances. Various genes, especially genes of importance to the metabolism of xenobiotic compounds, have been associated with MCS, but findings are inconsistent. The purpose of this ...... examined are of less importance to MCS than previously reported or that gene-environment interactions or significant degrees of genetic heterogeneity in MCS underlie inconsistent findings in the literature....... of this study was to investigate genetic susceptibility factors for MCS and self-reported chemical sensitivity in a population sample. Ninety six MCS patients and 1,207 controls from a general population divided into four severity groups of chemical sensitivity were genotyped for variants in the genes encoding...... compared in post hoc analyses with all individuals from the population sample (p=0.02). Genetic variants in paraoxonase 1 and methylene tetrahydrofolate reductase were not associated with MSC or with self-reported chemical sensitivity in the population sample. Our results suggest that variants in the genes...

  7. Multiple chemical sensitivity and idiopathic environmental intolerance (part one)

    OpenAIRE

    Watanabe, Mitsuyasu; Tonori, Hideki; Aizawa, Yoshiharu

    2003-01-01

    Multiple chemical sensitivity/idiopathic environmental intolerance (MCS/IEI) is a commonly used diagnostic term for a group of symptoms. These symptoms have been described and commented on for more than 15 years in the USA. Recently, it has also been observed in Japan. The main features of this syndrome are multiple symptoms involving in multiple organ systems that are precipitated by a variety of chemical substances with relapses and exacerbation under certain conditions when exposed to very...

  8. Influence of drying temperature on the chemical constituents of jaboticaba (Plinia Jaboticaba (Vell. Berg skin

    Directory of Open Access Journals (Sweden)

    Ana Paula de C. Alves

    2014-09-01

    Full Text Available Jaboticaba is a fruit native to Brazil. Its skin represents up to 43% of the fruit and contains high levels of fiber, minerals and phenolic compounds. The use of the skin waste adds value to the fruit. However, one of the drawbacks of skin storage is the high water content, which requires drying processes to preserve the skin without leading to the loss of nutrients and antioxidants. The influence of different drying temperatures on the levels of nutrients and antioxidants was investigated. Jaboticaba (Plinia jaboticaba (Vell. Berg, genotype Sabará skins were lyophilized or dried at three temperatures (30, 45, and 60ºC, using food dryers. The skins were then ground, stored (protected from light and subjected to analysis of proximate composition, vitamin C, phytate, polyphenols, anthocyanins and antioxidant activity. The drying process had little effect on the proximate composition of the flour, presenting significant difference only for crude protein, fiber and non-nitrogenous extract. The greatest preservation of chemical constituents occurs in the lyophilized jaboticaba skins. Among the drying temperatures tested, however, the skins dried at 45 and60°C had more highly preserved nutritional substances and antioxidants.

  9. Influence of chemical structure on skin reactions induced by antiepileptic drugs--the role of the aromatic ring.

    Science.gov (United States)

    Wang, Xiang-Qing; Shi, Xiao-Bing; Au, Ran; Chen, Fu-Shun; Wang, Fang; Lang, Sen-Yang

    2011-05-01

    Here we assessed whether the presence of an aromatic ring as a commonality in chemical structures of AEDs can explain skin reaction. We found that 164 cases of skin reactions associated with the use of AEDs were reported. Aromatic AEDs were suspected in 88.41% (145/164) of patients with skin reactions versus 59.80% (2316/3873) of patients without skin reactions. The presence of an aromatic ring in the chemical structure was associated with a significant increased risk of skin reactions (adjusted ROR 3.50; 95% CI 2.29, 5.35). Among the aromatic AEDs, skin reactions were significantly associated with carbamazepine, lamotrigine, and oxarbazepine. These results confirm that the presence of an aromatic ring as a common feature in chemical structures of AEDs partly explains AED-skin reactions. Skin reactions were reported triple as frequently with aromatic AEDs than with non-aromatic AEDs.

  10. A study of skin sensitivity to various allergens by skin prick test in patients of nasobronchial allergy

    Directory of Open Access Journals (Sweden)

    Prasad R

    2009-01-01

    Full Text Available Objective: To study skin sensitivity to various allergens in patients of nasobronchial allergy. Materials and Methods: 2880 skin prick tests with 60 allergens were performed in 48 patients of nasobronchial allergy. Results: Most common offending allergens were insects (21.2%, followed by dusts (12.0%, pollens (7.8%, animal dander (3.1%, and fungi (1.3%. The common insect antigen were locust female (33.3% followed by locust male (25%, grasshopper (20.8%, cricket (16.7%, cockroach female (16.7% and cockroach male (14.6%. Common dust allergens were house dust, wheat dust, cotton mill and paper dust. Among pollens, Amaranthus spinosus, Argemone mexicana, Adhatoda vasica, Ailanthus and Cannabis were found to be common allergens. In animal danders common offending allergens were cow dander and dog dander. Among fungi Aspergillus fumigatus, Aspergillus flavus, Alternaria teneis and Fusarium sodani were common allergens. Patients of bronchial asthma had associated allergic rhinitis in 80% cases. Conclusion: Common allergens in patients of nasobronchial allergy were identified. The data may prove useful in of allergen avoidance and immunotherapy in these patients.

  11. A nanofiber based artificial electronic skin with high pressure sensitivity and 3D conformability

    Science.gov (United States)

    Zhong, Weibin; Liu, Qiongzhen; Wu, Yongzhi; Wang, Yuedan; Qing, Xing; Li, Mufang; Liu, Ke; Wang, Wenwen; Wang, Dong

    2016-06-01

    Pressure sensors with 3D conformability are highly desirable components for artificial electronic skin or e-textiles that can mimic natural skin, especially for application in real-time monitoring of human physiological signals. Here, a nanofiber based electronic skin with ultra-high pressure sensitivity and 3D conformability is designed and built by interlocking two elastic patterned nanofibrous membranes. The patterned membrane is facilely prepared by casting conductive nanofiber ink into a silicon mould to form an array of semi-spheroid-like protuberances. The protuberances composed of intertwined elastic POE nanofibers and PPy@PVA-co-PE nanofibers afford a tunable effective elastic modulus that is capable of capturing varied strains and stresses, thereby contributing to a high sensitivity for pressure sensing. This electronic skin-like sensor demonstrates an ultra-high sensitivity (1.24 kPa-1) below 150 Pa with a detection limit as low as about 1.3 Pa. The pixelated sensor array and a RGB-LED light are then assembled into a circuit and show a feasibility for visual detection of spatial pressure. Furthermore, a nanofiber based proof-of-concept wireless pressure sensor with a bluetooth module as a signal transmitter is proposed and has demonstrated great promise for wireless monitoring of human physiological signals, indicating a potential for large scale wearable electronic devices or e-skin.Pressure sensors with 3D conformability are highly desirable components for artificial electronic skin or e-textiles that can mimic natural skin, especially for application in real-time monitoring of human physiological signals. Here, a nanofiber based electronic skin with ultra-high pressure sensitivity and 3D conformability is designed and built by interlocking two elastic patterned nanofibrous membranes. The patterned membrane is facilely prepared by casting conductive nanofiber ink into a silicon mould to form an array of semi-spheroid-like protuberances. The

  12. A histamine release assay to identify sensitization to Culicoides allergens in horses with skin hypersensitivity.

    Science.gov (United States)

    Wagner, Bettina; Childs, Bronwen A; Erb, Hollis N

    2008-12-15

    Skin hypersensitivity is an allergic disease induced in horses by allergens of Culicoides midges. The condition is typically diagnosed by clinical signs and in some horses in combination with allergy testing such as intradermal skin testing or serological allergen-specific IgE determination. Here, we describe an alternative method for allergy testing: a histamine release assay (HRA) that combines the functional aspects of skin testing with the convenience of submitting a blood sample. The assay is based on the principle that crosslinking of allergen-specific IgE bound via high-affinity IgE receptors to the surfaces of mast cells and basophils induces the release of inflammatory mediators. One of these mediators is histamine. The histamine was then detected by a colorimetric enzyme-linked immunosorbent assay. The histamine assay was used to test 33 horses with skin hypersensitivity and 20 clinically healthy control animals for histamine release from their peripheral blood basophils after stimulation with Culicoides allergen extract or monoclonal anti-IgE antibody. An increased histamine release was observed in the horses with skin hypersensitivity compared to the control group after allergen-specific stimulation with Culicoides extract (p=0.023). In contrast, stimulation with anti-IgE induced similar amounts of released histamine in both groups (p=0.46). For further evaluation of the HRA, we prepared a receiver operating-characteristic (ROC) curve and performed a likelihood-ratio analysis for assay interpretation. Our results suggested that the assay is a valuable diagnostic tool to identify sensitization to Culicoides allergens in horses. Because some of the clinically healthy horses also showed sensitization to Culicoides extract, the assay cannot be used to distinguish allergic from non-allergic animals. The observation that sensitization is sometimes detectable in non-affected animals suggested that clinically healthy horses use immune mechanisms to control the

  13. Chlorine Dioxide Induced Multiple Chemical Sensitivity: MMPI Validity Problems.

    Science.gov (United States)

    Tentoni, Stuart C.

    This paper discusses Minnesota Multiphasic Personality Inventory (MMPI) data obtained from individuals exposed to chlorine dioxide in the workplace who developed Multiple Chemical Sensitivity Syndrome. The paper explores current research on chlorine dioxide exposed persons who were misdiagnosed on the basis of MMPI interpretations. Difficulties…

  14. Evaluation of a topical treatment for the relief of sensitive skin

    Directory of Open Access Journals (Sweden)

    Heinicke IR

    2015-07-01

    Full Text Available Ingrid R Heinicke,1 Damian H Adams,2 Tanya M Barnes,1 Kerryn A Greive1 1Ego Pharmaceuticals, Braeside, VIC, Australia; 2Mawson Institute, University of South Australia, Mawson Lakes, SA, Australia Background: Approximately, 50% of the population claim to have sensitive skin, which has created an important challenge for dermatologists and the cosmetic industry. This study evaluates the properties of QV Face Rescue Gel (Rescue Gel that contains a combination of moisturizing and anti-irritant ingredients, and which is used to relieve the symptoms of sensitive facial skin. Methods: The ability of Rescue Gel to induce collagen types I and III in cultured neonatal human foreskin fibroblasts compared to transforming growth factor beta 1, a known potent inducer of collagen types I and III, was measured using immunofluorescence staining. Furthermore, healthy volunteers were recruited to measure the potential for Rescue Gel to reduce erythema induced by solar-simulated ultraviolet radiation on the skin compared to 0.5% hydrocortisone cream (positive control as well as it's ability to decrease transepidermal water loss compared to baseline levels. In addition, the formulation was tested for its potential to be 1 nonstinging using a facial sting/discomfort assay performed on volunteers who reacted positively to lactic acid, 2 nonirritating as determined by repeat insult patch tests, and 3 noncomedogenic. Results: Rescue Gel significantly induced collagen types I and III in cultured human foreskin fibroblasts similarly to transforming growth factor beta 1. In volunteers, Rescue Gel was shown to significantly reduce erythema induced by solar-simulated ultraviolet radiation similarly to 0.5% hydrocortisone, and to significantly reduce transepidermal water loss compared to baseline levels. Further, the formulation was found to be nonstinging, nonirritating, and noncomedogenic. No adverse events were observed. Conclusion: In this study, Rescue Gel has been shown

  15. Chemosensory perception, symptoms and autonomic responses during chemical exposure in multiple chemical sensitivity

    DEFF Research Database (Denmark)

    Andersson, Linus; Claeson, Anna Sara; Dantoft, Thomas Meinertz;

    2016-01-01

    Purpose: Multiple chemical sensitivity (MCS) is a prevalent medically unexplained symptom characterized by symptom reactions to everyday chemical exposure below hygienic thresholds. The aim of this study was to investigate the expressions of hyper-reactivity in MCS during whole-body exposure to l...

  16. Differential modulation of CXCR4 and CD40 protein levels by skin sensitizers and irritants in the FSDC cell line

    OpenAIRE

    Neves, Bruno Miguel; Cruz, Maria Teresa; Francisco, Vera; Gonçalo, Margarida; Figueiredo, Américo; Duarte, Carlos B.; Lopes, Maria Celeste

    2008-01-01

    The development of non-animal methods for skin sensitization testing is an urgent challenge. Some of the most promising in vitro approaches are based on the analysis of phenotypical and functional modifications induced by sensitizers in dendritic cell models. In this work, we evaluated, for the first time, a fetal skin-derived dendritic cell line (FSDC) as a model to discriminate between sensitizers and irritants, through analysis of their effects on CD40 and CXCR4 protein expression. The che...

  17. A theoretical justification for the study of skin sensitivity in patients with bell's palsy

    OpenAIRE

    Cárdenas Palacios, Carlos Andrés; Universidad de la Sabana-Bogotá,Colombia

    2015-01-01

    The purpose of this review is to highlight the importance of conducting studies to estimate the level of association between measures of skin sensitivity, facial region, facial paralysis level, and time of evolution, in patients with Bells palsy; the above stems from the theoretical review of various studies that have found differences in measures of pressure threshold, two-point discrimination and appreciation of the vibration between different facial regions, both in patients with this kind...

  18. [The experimental application of chitosan membrane for treating chemical burns of the skin].

    Science.gov (United States)

    Pogorielov, M; Kalinkevich, O; Gortinskaya, E; Moskalenko, R; Tkachenko, Yu

    2014-01-01

    The basic method for skin damage treatment, including chemical wounds, is a topical application of different agents. Their objective is to repair structure of the skin and its functions. All dressings for treating wounds are classified as biological, artificial and composites containing both synthetic and natural materials. There are many studies concerning application of chitosan, which is a derivate of natural polymer chitin, as a basis for topical materials to treat burns. However, data are rather limited about application of chitosan for treating acid burns. Thus, the aim of research is to study the morphological futures of skin regeneration after the chemical burn applying chitosan membranes. We performed the experiment on 60 young rats (3 months old) with the chemical burns of third-degree (IIIA degree) to study the morphofunctional features of skin regeneration. Later we applied the chitosan membranes on the burns. We carried out a histologic investigation on the biopsy specimens of wound to determine the morphological features of wound regeneration. The results confirmed that earlier granulation and epithelialization of the skin surface happened as the chitosan membrane was applied on the acid effected surface. The final result of the application of chitosan film is to achieve full epithelialization, preserve the structure of tissues beneath the burn and prevent getting scars.

  19. LSENS - GENERAL CHEMICAL KINETICS AND SENSITIVITY ANALYSIS CODE

    Science.gov (United States)

    Bittker, D. A.

    1994-01-01

    LSENS has been developed for solving complex, homogeneous, gas-phase, chemical kinetics problems. The motivation for the development of this program is the continuing interest in developing detailed chemical reaction mechanisms for complex reactions such as the combustion of fuels and pollutant formation and destruction. A reaction mechanism is the set of all elementary chemical reactions that are required to describe the process of interest. Mathematical descriptions of chemical kinetics problems constitute sets of coupled, nonlinear, first-order ordinary differential equations (ODEs). The number of ODEs can be very large because of the numerous chemical species involved in the reaction mechanism. Further complicating the situation are the many simultaneous reactions needed to describe the chemical kinetics of practical fuels. For example, the mechanism describing the oxidation of the simplest hydrocarbon fuel, methane, involves over 25 species participating in nearly 100 elementary reaction steps. Validating a chemical reaction mechanism requires repetitive solutions of the governing ODEs for a variety of reaction conditions. Analytical solutions to the systems of ODEs describing chemistry are not possible, except for the simplest cases, which are of little or no practical value. Consequently, there is a need for fast and reliable numerical solution techniques for chemical kinetics problems. In addition to solving the ODEs describing chemical kinetics, it is often necessary to know what effects variations in either initial condition values or chemical reaction mechanism parameters have on the solution. Such a need arises in the development of reaction mechanisms from experimental data. The rate coefficients are often not known with great precision and in general, the experimental data are not sufficiently detailed to accurately estimate the rate coefficient parameters. The development of a reaction mechanism is facilitated by a systematic sensitivity analysis

  20. Flexible polymer transistors with high pressure sensitivity for application in electronic skin and health monitoring

    Science.gov (United States)

    Schwartz, Gregor; Tee, Benjamin C.-K.; Mei, Jianguo; Appleton, Anthony L.; Kim, Do Hwan; Wang, Huiliang; Bao, Zhenan

    2013-05-01

    Flexible pressure sensors are essential parts of an electronic skin to allow future biomedical prostheses and robots to naturally interact with humans and the environment. Mobile biomonitoring in long-term medical diagnostics is another attractive application for these sensors. Here we report the fabrication of flexible pressure-sensitive organic thin film transistors with a maximum sensitivity of 8.4 kPa-1, a fast response time of 15,000 cycles and a low power consumption of health monitoring and remote diagnostics in cardiovascular medicine.

  1. Large-area semi-transparent light-sensitive nanocrystal skins.

    Science.gov (United States)

    Akhavan, Shahab; Guzelturk, Burak; Sharma, Vijay Kumar; Demir, Hilmi Volkan

    2012-11-05

    We report a large-area, semi-transparent, light-sensitive nanocrystal skin (LS-NS) platform consisting of single monolayer colloidal nanocrystals. LS-NS devices, which were fabricated over areas up to 48 cm(2) using spray-coating and several cm-squares using dip-coating, are operated on the principle of photogenerated potential buildup, unlike the conventional charge collection. Implementing proof-of-concept devices using CdTe nanocrystals with ligand removal, we observed a substantial sensitivity enhancement factor of ~73%, accompanied with a 3-fold faster response time (smart buildings.

  2. Tracking thermal fronts with temperature-sensitive, chemically reactive tracers

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, B.A.; Birdsell, S.A.

    1987-01-01

    Los Alamos is developing tracer techniques using reactive chemicals to track thermal fronts in fractured geothermal reservoirs. If a nonadsorbing tracer flowing from the injection to production well chemically reacts, its reaction rate will be a strong function of temperature. Thus the extent of chemical reaction will be greatest early in the lifetime of the system, and less as the thermal front progresses from the injection to production well. Early laboratory experiments identified tracers with chemical kinetics suitable for reservoirs in the temperature range of 75 to 100/sup 0/C. Recent kinetics studies have focused on the kinetics of hydrolysis of derivatives of bromobenzene. This class of reactions can be used in reservoirs ranging in temperature from 150 to 275/sup 0/C, which is of greater interest to the geothermal industry. Future studies will include laboratory adsorption experiments to identify possibly unwanted adsorption on granite, development of sensitive analytical techniques, and a field demonstration of the reactive tracer concept.

  3. Quantum-chemical calculations of dye-sensitized semiconductor nanocrystals

    Science.gov (United States)

    Persson, P.; Lundqvist, M. J.; Nilsing, M.; van Duin, A. C. T.; Goddard, W. A., III

    2006-08-01

    Quantum chemical calculations providing detailed information of dye-sensitized semiconductor nanocrystals are presented. The calculations are used to elucidate both structural and electronic properties of photoelectrochemical devices, such as environmentally friendly Dye-Sensitized Solar Cells (DSSCs), at the molecular level. Quantum chemical calculations have recently been performed on both organic and organometallic dye molecules attached to titanium dioxide (TiO II) nanocrystals via different anchor and spacer groups. Strategies to make accurate quantum chemical calculations, e.g. at the DFT level of theory, on increasingly realistic models of such dye-sensitized semiconductor interfaces are presented. The ability of different anchor and spacer groups to act as mediators of ultrafast photo-induced electron injection from the dye molecules into the semiconductor nanocrystals is, in particular, discussed in terms of calculated electronic coupling strengths, and direct comparisons with experimental information are made whenever possible. Progress in the development of multi-scale simulation techniques using so called reactive force fields is illustrated for dye-sensitized solar cell systems.

  4. Self-reported occupational exposure to chemical and physical factors and risk of skin problems

    DEFF Research Database (Denmark)

    Alfonso, Jose Hernan; Thyssen, Jacob P; Tynes, Tore;

    2015-01-01

    Prospective studies on occupational dermatoses in the general working population are sparse. This study investigated prospectively the impact of self-reported occupational exposure to chemicals and physical factors on the risk of skin problems. The cohort comprised respondents drawn randomly from...

  5. [Combination of a universal antidote and temporary skin substitute for chemical burns: Extended case report].

    Science.gov (United States)

    Liodaki, E; Schopp, B E; Lindert, J; Krämer, R; Kisch, T; Mailänder, P; Stang, F

    2015-09-01

    In this article we describe our experiences in the treatment of chemical burns with Diphoterine(®) solution and Suprathel(®) as a temporary skin substitute material, a treatment which in the past was not commonly used for this pattern of injuries. In the study period from October 2012 to December 2013 we treated five patients (four male and one female including two children and three adults) with chemical burns by decontamination with Diphoterine(®) and wound covering with Suprathel(®). The control group included five patients with similar injury patterns who were treated with Diphoterine(®) and occlusive wound dressings. No wound infections occurred in any of the five cases and no interactions were observed between Suprathel(®) and the chemical substance involved. In four cases the skin areas with IIa-IIb degree damage showed good wound healing and only slight scarring in the follow-up after 3 months and one of the five patients had to be treated surgically. Suprathel(®) can be used as a temporary skin substitute for the treatment of skin burns and is also available for the treatment of chemical burns.

  6. The role of chemical peeling in the treatment of photodamaged skin.

    Science.gov (United States)

    Matarasso, S L; Salman, S M; Glogau, R G; Rogers, G S

    1990-10-01

    Management of the aging face involves evaluation of the degree of solar elastosis, rhytidosis, and the structural changes associated with senescent skin. Chemical facial exfoliation is divided into deep, medium, and superficial based upon depth of penetration of the caustic agent used. Knowledge of the appropriate indications and technique are essential in obtaining optimal clinical results.

  7. Role of the Slug Transcription Factor in Chemically-Induced Skin Cancer

    Directory of Open Access Journals (Sweden)

    Kristine von Maltzan

    2016-02-01

    Full Text Available The Slug transcription factor plays an important role in ultraviolet radiation (UVR-induced skin carcinogenesis, particularly in the epithelial-mesenchymal transition (EMT occurring during tumor progression. In the present studies, we investigated the role of Slug in two-stage chemical skin carcinogenesis. Slug and the related transcription factor Snail were expressed at high levels in skin tumors induced by 7,12-dimethylbenz[α]anthracene application followed by 12-O-tetradecanoylphorbol-13-acetate (TPA treatment. TPA-induced transient elevation of Slug and Snail proteins in normal mouse epidermis and studies in Slug transgenic mice indicated that Slug modulates TPA-induced epidermal hyperplasia and cutaneous inflammation. Although Snail family factors have been linked to inflammation via interactions with the cyclooxygenase-2 (COX-2 pathway, a pathway that also plays an important role in skin carcinogenesis, transient TPA induction of Slug and Snail appeared unrelated to COX-2 expression. In cultured human keratinocytes, TPA induced Snail mRNA expression while suppressing Slug expression, and this differential regulation was due specifically to activation of the TPA receptor. These studies show that Slug and Snail exhibit similar patterns of expression during both UVR and chemical skin carcinogenesis, that Slug and Snail can be differentially regulated under some conditions and that in vitro findings may not recapitulate in vivo results.

  8. Singular vector decomposition for sensitivity analyses of tropospheric chemical scenarios

    Directory of Open Access Journals (Sweden)

    N. Goris

    2011-06-01

    Full Text Available Observations of the chemical state of the atmosphere typically provide only sparse snapshots of the state of the system due to their insufficient temporal and spatial density. Therefore the measurement configurations need to be optimised to get a best possible state estimate. One possibility to optimise the state estimate is provided by observation targeting of sensitive system states, to identify measurement configurations of best value for forecast improvements. In recent years, numerical weather prediction adapted singular vector analysis with respect to initial values as a novel method to identify sensitive states. In the present work, this technique is transferred from meteorological to chemical forecast. Besides initial values, emissions are investigated as controlling variables. More precisely uncertainties in the amplitude of the diurnal profile of emissions are analysed, yielding emission factors as target variables. Singular vector analysis is extended to allow for projected target variables not only at final time but also at initial time. Further, special operators are introduced, which consider the combined influence of groups of chemical species.

    As a preparation for targeted observation calculations, the concept of adaptive observations is studied with a chemistry box model. For a set of six different scenarios, the VOC versus NOx limitation of the ozone formation is investigated. Results reveal, that the singular vectors are strongly dependent on start time and length of the simulation. As expected, singular vectors with initial values as target variables tend to be more sensitive to initial values, while emission factors as target variables are more sensitive to simulation length. Further, the particular importance of chemical compounds differs strongly between absolute and relative error growth.

  9. Physical and chemical analyzis of chardonnay wine with different periods of skin contact

    Directory of Open Access Journals (Sweden)

    Giriboni Pedro Pohlmann

    2016-01-01

    Full Text Available Aromatic precursors are precisely in the skin of grapes and nearby cells, and therefore there is a greater expression of the varietal aromas and aromatic precursors when the wine passes through this skin contact, as well as changes in product color. The aim of this study was to evaluate the physical and chemical characteristics of Chardonnay wine that has gone through different periods of skin contact. Chardonnay grapes, grown in vineyards located in the town of Bagé, in Campanha Gaúcha, were de-stemmed, crushed and a sulfur dioxide (50 mg/L−1 was addeded. The experimental design was a 4 × 3 factorial of 4 treatments with 3 repetitions: T1, the wine obtained directly from pressing machine; T2, skin contact for 2 days; T3, skin contact for 4 days and T4, skin contact for 6 days. After the end of malolactic fermentation wines went under − 2∘C for the tartaric stabilization. There were analyzed the variables alcohol, total acidity, volatile acidity, total polyphenols, glycerol, gluconic acid and 420, 520 and 620 colors by infrared spectroscopy method by Fourier transform and the means were compared by 5% Tukey test. There was a significant differencein variables alcohol, volatile acidit, glucanic acid and color index of 420 nm (yellow.

  10. Food Sensitivity in Children with Acute Urticaria in Skin Prick Test: Single Center Experience

    Directory of Open Access Journals (Sweden)

    Hatice Eke Gungor

    2015-11-01

    Full Text Available Aim: Families of children with acute urticaria often think that there is food allergy in children with urticaria and insist for skin tests. In this study, it was aimed to determine whether skin prick tests are necessary in cases presented with acute urticaria, in whom other causes of acute urticaria are excluded. Material and Method: A test panel involving cow milk, egg white, wheat, hazelnut, peanut, soybean, walnut, sesame, and tuna fish antigens was applied to the children presented with acute urticaria between 1 August 2013 and 1 August 2014, in whom other causes of acute urticaria were excluded and suspected food allergy was reported by parents. Results: Overall, 574 children aged 1-14 years were included to the study. Of the patients, sensitization against at least one food antigen was detected in 22.3% (128/574 of the patients. This rate was found to be 31.9% among those younger than 3 years, while 19.3% in those older than 3 years. Overall, sensitization rates against food allergen in panel were as follows: egg white, 7.3%; wheat, 3.3%; cow milk, 2.7%,; sesame, 2.8%; hazelnut, 2.4%; soybean, 2.3%; peanut, 1.9%, walnut, 1.6%; tuna fish, 1.6%. In general, the history of patients wasn%u2019t compatible with food sensitization detected. Discussion: Sensitization to food allergens is infrequent in children presented with acute urticaria, particularly among those older than 3 years despite expressions of parent and skin prick tests seems to be unnecessary unless strongly suggestive history is present.

  11. Flash Mob Project Creates Awareness of Environmental Sensitivities: Making "Multiple Chemical Sensitivity" a Household Name

    Science.gov (United States)

    Smith, Melva Gail

    2011-01-01

    Having severe Asthma and trying to maintain a social life isn't easy, but when one adds the disability of Multiple Chemical Sensitivity (MCS) to the combination, the challenges become even tougher. As a dancer with both Asthma and MCS, the author was forced to give up the sport for 15 years before finding a group of line dancers that were…

  12. Predicting rare events in chemical reactions: Application to skin cell proliferation.

    Science.gov (United States)

    Lee, Chiu Fan

    2010-08-01

    In a well-stirred system undergoing chemical reactions, fluctuations in the reaction propensities are approximately captured by the corresponding chemical Langevin equation. Within this context, we discuss in this work how the Kramers escape theory can be used to predict rare events in chemical reactions. As an example, we apply our approach to a recently proposed model on cell proliferation with relevance to skin cancer [P. B. Warren, Phys. Rev. E 80, 030903 (2009)]. In particular, we provide an analytical explanation for the form of the exponential exponent observed in the onset rate of uncontrolled cell proliferation.

  13. Multiple chemical sensitivity and idiopathic environmental intolerance (part two).

    Science.gov (United States)

    Watanabe, Mitsuyasu; Tonori, Hideki; Aizawa, Yoshiharu

    2003-01-01

    Multiple chemical sensitivity/idiopathic environmental intolerance (MCS/IEI) is a commonly used diagnostic term for a group of symptoms without apparent organic basis. The symptoms are characteristic of dysfunction in multiple organ systems. They wax and wane fluctuate according to exposure to low levels of chemical agents in the patient's environment, and sometimes begin after a distinct environmental change or injury such an industrial accident or chemical introduced after remodeling. Although traditional medical organizations have not agreed on a definition for this syndrome, it is being increasingly recognized and makes up an increasing percentage of the caseload at occupational/environmental medical clinics.Part two of this review article discusses diagnosis, clinical examination, long-term follow up of MCS/IEI, and the role of physicians, research on odor and treatment, diseases with similar symptoms, and further research regarding MCS/IEI patients.

  14. Overview of the status of predictive computer models for skin sensitization (JRC Expert meeting on pre- and pro-haptens )

    Science.gov (United States)

    No abstract was prepared or requested. This is a short presentation aiming to present a status of what in silico models and approaches exists in the prediction of skin sensitization potential and/or potency.

  15. Quantitative study of stratum corneum ceramides contents in patients with sensitive skin.

    Science.gov (United States)

    Cho, Hee Jin; Chung, Bo Young; Lee, Hee Bong; Kim, Hye One; Park, Chun Wook; Lee, Cheol Heon

    2012-03-01

    People with sensitive skin (SS) are those who state their skin is more sensitive than that of average persons. The stratum corneum is responsible for maintaining skin barrier function. Ceramides, major constituents of stratum corneum lipids, have been shown to predominantly contribute to the role. It has been suggested that barrier function in SS is decreased. However, we could find very few reports about stratum corneum ceramides in SS. This study was done to find out differences in stratum corneum ceramides between SS and non-SS groups. Fifty individuals (20 with SS and 30 with non-SS) were recruited. Lactic acid sting test (LAST) was performed on the left cheek. On six sites including the right cheek, arm, thigh, leg, back and palm, transepidermal water loss (TEWL) and erythema index (EI) were measured. On the above six sites, stratum corneum sheets were obtained by stripping with cyanoacrylate resin and stratum corneum lipids were extracted, then, analyzed by high-performance liquid chromatography electrospray ionization mass spectrometry. LAST scores were higher in the SS group, but not statistically significant. There were no differences in TEWL and EI values between the two groups. The mean value of the quantity of stratum corneum ceramides on the face was significantly lower in the SS group. On other sites, mean values were also lower in the SS group, but not statistically significant. The quantity of ceramides was significantly decreased in the face of the SS group compared to that of the non-SS group. These results suggest that the decrease in stratum corneum ceramides on facial skin could be related to SS development.

  16. Is Cytox 3522 (10% methylene-bis-thiocyanate) a human skin sensitizer?

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Hamann, K

    1983-01-01

    Methylene-bis-thiocyanate is an antimicrobial agent in Cytox 3522 (American Cyanamid Corporation) and Nalco 206 (Nalco Chemical Company). Both are wide-spectrum industrial biocides. Cytox 3522 showed a strong sensitization potential in guineau pigs using the Guinea Pig Maximization Test and the O......Methylene-bis-thiocyanate is an antimicrobial agent in Cytox 3522 (American Cyanamid Corporation) and Nalco 206 (Nalco Chemical Company). Both are wide-spectrum industrial biocides. Cytox 3522 showed a strong sensitization potential in guineau pigs using the Guinea Pig Maximization Test...

  17. Utilization of reconstructed cultured human skin models as an alternative skin for permeation studies of chemical compounds

    OpenAIRE

    Kano, Satoshi; 藤堂, 浩明; 杉江, 謙一; 藤本, 英哲; 中田, 圭一; 徳留, 嘉寛; 橋本, フミ惠; 杉林, 堅次

    2010-01-01

    Two reconstructed human skin models, EpiskinSM and EpiDermTM, have been approved as alternative membranes for skin corrosive/irritation experiments due to their close correlation with animal skin. Such reconstructed human skin models were evaluated as alternative membranes for skin permeation experiments. Seven drugs with different lipophilicities and almost the same molecular weight were used as test penetrants. Relationships were investigated between permeability coefficients (P values) of ...

  18. Sub-categorisation of skin corrosive chemicals by the EpiSkin™ reconstructed human epidermis skin corrosion test method according to UN GHS: revision of OECD Test Guideline 431.

    Science.gov (United States)

    Alépée, N; Grandidier, M H; Cotovio, J

    2014-03-01

    The EpiSkin™ skin corrosion test method was formally validated and adopted within the context of OECD TG 431 for identifying corrosive and non-corrosive chemicals. The EU Classification, Labelling and Packaging Regulation (EU CLP) system requires the sub-categorisation of corrosive chemicals into the three UN GHS optional subcategories 1A, 1B and 1C. The present study was undertaken to investigate the usefulness of the validated EpiSkin™ test method to identify skin corrosive UN GHS Categories 1A, 1B and 1C using the original and validated prediction model and adapted controls for direct MTT reduction. In total, 85 chemicals selected by the OECD expert group on skin corrosion were tested in three independent runs. The results obtained were highly reproducible both within (>80%) and between (>78%) laboratories when compared with historical data. Moreover the results obtained showed that the EpiSkin™ test method is highly sensitive (99%) and specific (80%) in discriminating corrosive from non-corrosive chemicals and allows reliable and relevant identification of the different skin corrosive UN GHS subcategories, with high accuracies being obtained for both UN GHS Categories 1A (83%) and 1B/1C (76%) chemicals. The overall accuracy of the test method to subcategorise corrosive chemicals into three or two UN GHS subcategories ranged from 75% to 79%. Considering those results, the revised OECD Test Guideline 431 permit the use of EpiSkin™ for subcategorising corrosive chemicals into at least two classes (Category 1A and Category 1B/1C).

  19. Altered thermal sensitivity in facial skin in chronic whiplash-associated disorders

    Institute of Scientific and Technical Information of China (English)

    Birgitta Haggman-Henrikson; Ewa Lampa; Erik Nordh

    2013-01-01

    There is a close functional relationship between the jaw and neck regions and it has been suggested that trigeminal sensory impairment can follow whiplash injury. Inclusion of manageable routines for valid assessment of the facial sensory capacity is thus needed for comprehensive evaluations of patients exposed to such trauma. The present study investigated facial thermal thresholds in patients with chronic whiplash-associated disorders (WADs) with both a qualitative method and quantitative sensory testing (QST). Ten women with pain and dysfunction following a whiplash injury were compared to 10 healthy age-matched women. Thermal detection thresholds were assessed by qualitative chair-side testing and by QST according to the method-of-limits. Seven test sites in the facial skin (overlying each trigeminal branch bilaterally, and the midpoint of the chin) were examined. The detection warm and cold thresholds were defined as the mean values of 10 individual thresholds. For the WAD patients, the qualitative assessment demonstrated both reduced and increased sensitivity compared to the healthy, whereas QST systematically showed significantly higher detection thresholds (i.e., decreased sensitivity) for both cold and warm stimuli. For the individuals who were assessed as having increased sensitivity in the qualitative assessment, the QST displayed either normal or higher thresholds, i.e., decreased sensitivity. The results suggest that QST is more sensitive for detecting thermal sensory disturbances in the face than a qualitative method. The impaired thermal sensitivity among the patients corroborates the notion of altered thermal detection capacity induced by WAD-related pain.

  20. Niacin Skin Sensitivity Is Increased in Adolescents at Ultra-High Risk for Psychosis.

    Directory of Open Access Journals (Sweden)

    Gregor E Berger

    Full Text Available Most studies provide evidence that the skin flush response to nicotinic acid (niacin stimulation is impaired in schizophrenia. However, only little is known about niacin sensitivity in the ultra-high risk (UHR phase of psychotic disorders.We compared visual ratings of niacin sensitivity between adolescents at UHR for psychosis according to the one year transition outcome (UHR-T n = 11; UHR-NT n = 55 with healthy controls (HC n = 25 and first episode schizophrenia patients (FEP n = 25 treated with atypical antipsychotics.Contrary to our hypothesis niacin sensitivity of the entire UHR group was not attenuated, but significantly increased compared to the HC group, whereas no difference could be found between the UHR-T and UHR-NT groups. As expected, niacin sensitivity of FEP was attenuated compared to HC group. In UHR individuals niacin sensitivity was inversely correlated with omega-6 and -9 fatty acids (FA, but positively correlated with phospholipase A2 (inPLA2 activity, a marker of membrane lipid repair/remodelling.Increased niacin sensitivity in UHR states likely indicates an impaired balance of eicosanoids and omega-6/-9 FA at a membrane level. Our findings suggest that the emergence of psychosis is associated with an increased mobilisation of eicosanoids prior to the transition to psychosis possibly reflecting a "pro-inflammatory state", whereas thereafter eicosanoid mobilisation seems to be attenuated. Potential treatment implications for the UHR state should be further investigated.

  1. Sensitivity of different areas of the flexor aspect of the human forearm to corticosteroid-induced skin blanching.

    Science.gov (United States)

    Meyer, E; Smith, E W; Haigh, J M

    1992-10-01

    The intensity of corticosteroid-induced blanching has been found to vary at different areas of the flexor aspect of the human forearm. A retrospective analysis of 38,880 observations of skin blanching in 56 volunteers was conducted to assess the sensitivity of forearm skin to betamethasone 17-valerate. The mid-forearm appears to be more sensitive to the blanching response than do the areas close to the wrist or elbow. These results indicate that each preparation under evaluation should be applied to several sites along the forearm when using the human skin blanching assay in order to obtain an accurate comparative assessment of corticosteroid release from topical delivery vehicles.

  2. Reproducibility of the heat/capsaicin skin sensitization model in healthy volunteers

    Directory of Open Access Journals (Sweden)

    Cavallone LF

    2013-11-01

    Full Text Available Laura F Cavallone,1 Karen Frey,1 Michael C Montana,1 Jeremy Joyal,1 Karen J Regina,1 Karin L Petersen,2 Robert W Gereau IV11Department of Anesthesiology, Washington University in St Louis, School of Medicine, St Louis, MO, USA; 2California Pacific Medical Center Research Institute, San Francisco, CA, USAIntroduction: Heat/capsaicin skin sensitization is a well-characterized human experimental model to induce hyperalgesia and allodynia. Using this model, gabapentin, among other drugs, was shown to significantly reduce cutaneous hyperalgesia compared to placebo. Since the larger thermal probes used in the original studies to produce heat sensitization are now commercially unavailable, we decided to assess whether previous findings could be replicated with a currently available smaller probe (heated area 9 cm2 versus 12.5–15.7 cm2.Study design and methods: After Institutional Review Board approval, 15 adult healthy volunteers participated in two study sessions, scheduled 1 week apart (Part A. In both sessions, subjects were exposed to the heat/capsaicin cutaneous sensitization model. Areas of hypersensitivity to brush stroke and von Frey (VF filament stimulation were measured at baseline and after rekindling of skin sensitization. Another group of 15 volunteers was exposed to an identical schedule and set of sensitization procedures, but, in each session, received either gabapentin or placebo (Part B.Results: Unlike previous reports, a similar reduction of areas of hyperalgesia was observed in all groups/sessions. Fading of areas of hyperalgesia over time was observed in Part A. In Part B, there was no difference in area reduction after gabapentin compared to placebo.Conclusion: When using smaller thermal probes than originally proposed, modifications of other parameters of sensitization and/or rekindling process may be needed to allow the heat/capsaicin sensitization protocol to be used as initially intended. Standardization and validation of

  3. Skin Sensitive Difference of Human Body Sections under Clothing--Multiple Analysis of Skin Surface Temperature Changes

    Institute of Scientific and Technical Information of China (English)

    李俊; 吴海燕; 张渭源

    2003-01-01

    A new researching method on clothing comfort perception is developed.By it the skin surface temperature changes and subjective psychological perception of human body sections stimulated by the same cold stimulation are studied.With the multiple comparison analysis method the changing laws of skin temperature of main human body sections is obtained.

  4. SA-I Mechanoreceptor Position in Fingertip Skin May Impact Sensitivity to Edge Stimuli

    Directory of Open Access Journals (Sweden)

    Gregory J. Gerling

    2010-01-01

    Full Text Available Background: The skin plays a role in conditioning mechanical indentation into distributions of stress/strain that mechanoreceptors convert into neural signals. Solid mechanics methods have modelled the skin to predict the in vivo neural response from mechanoreceptors. Despite their promise, current models cannot explain the role that anatomical positioning and receptor organ morphology play in producing differences in neural response. This work hypothesises that the skin's intermediate ridges may help explain, in part, the sensitivity of slowly adapting type I (SA-I mechanoreceptors to edge stimuli. Method: Two finite-element models of the fingertip were built, validated and used to analyse the functionality of the intermediate ridges. One of the two-dimensional, cross-sectional models included intermediate ridges, while the other did not. The analysis sought to determine if intermediate ridges (1 increase the magnitude of strain energy density (SED near the SA-I location and (2 help differentiate one 2.0-mm indenter from two 0.5-mm wide indenters with a 1.0-mm gap. Results: Higher concentrations of SED were found near the tips of the intermediate ridges, the anatomical location that coincides with the SA-I receptors. This first result suggested that the location of the SA-Is in the stiffer epidermal tissue helps magnify their response to edge stimuli. The second result was that both models were equally capable of predicting the spatial structure within the in vivo neural responses, and therefore the addition of intermediate ridges did not help in differentiating the indenters. Conclusion: The finding, a 15%–35% increase in response when the sampling point lies within the stiffer tissue at the same depth, seeks to inform the positioning of force sensors in robotic skin substrates.

  5. Sensitivity and entanglement in the avian chemical compass

    Science.gov (United States)

    Zhang, Yiteng; Berman, Gennady P.; Kais, Sabre

    2014-10-01

    The radical pair mechanism can help to explain avian orientation and navigation. Some evidence indicates that the intensity of external magnetic fields plays an important role in avian navigation. In this paper, using a two-stage model, we demonstrate that birds could reasonably detect the directions of geomagnetic fields and gradients of these fields using a yield-based chemical compass that is sensitive enough for navigation. Also, we find that the lifetime of entanglement in this proposed compass is angle dependent and long enough to allow adequate electron transfer between molecules.

  6. Sensitivity and Entanglement in the Avian Chemical Compass

    CERN Document Server

    Zhang, Yiteng; Kais, Sabre

    2014-01-01

    The Radical Pair Mechanism can help to explain avian orientation and navigation. Some evidence indicates that the intensity of external magnetic fields plays an important role in avian navigation. In this paper, based on a two-stage strategy, we demonstrate that birds could reasonably detect the directions of geomagnetic fields and gradients of these fields using a yield-based chemical compass that is sensitive enough for navigation. Also, we find that the lifetime of entanglement in this proposed compass is angle-dependent and long enough to allow adequate electron transfer between molecules.

  7. Multiple chemical sensitivity (MCS) : Idiopathic environmental intolerances (IEI).

    Science.gov (United States)

    Wolf, C

    1996-09-01

    Multiple Chemical Sensitivity (MCS) is a systemic disorder causing central nervous, irritative and gastrointestinal symptoms, and can be included in the category of "idiopathic environmental intolerance" (IEI). This term describes phenomena with multiple, recurrent symptoms associated with various environmental factors that are tolerated by most people without problems. Those advocating these concepts attribute the symptoms to exogenous substances. Those opposing them explain the phenomena by classical conditioning or other psychopathological processes. To the extent that controlled studies are available, they have not furnished any hard evidence for toxic or immunological causes. In addition to psychopathological origins, neurobiological processes are also implicated.

  8. Use of silicon for skin and hair care: an approach of chemical forms available and efficacy*

    Science.gov (United States)

    de Araújo, Lidiane Advincula; Addor, Flavia; Campos, Patrícia Maria Berardo Gonçalves Maia

    2016-01-01

    Silicon is the second most abundant element on Earth, and the third most abundant trace element in human body. It is present in water, plant and animal sources. On the skin, it is suggested that silicon is important for optimal collagen synthesis and activation of hydroxylating enzymes, improving skin strength and elasticity. Regarding hair benefits, it was suggested that a higher silicon content in the hair results in a lower rate of hair loss and increased brightness. For these beneficial effects, there is growing interest in scientific studies evaluating the efficacy and safety of using dietary supplements containing silicon. Its use aims at increasing blood levels of this element and improving the skin and its annexes appearance. There are different forms of silicon supplements available and the most important consideration to be made in order to select the best option is related to safety and bioavailability. Silicon supplements are widely used, though there is wide variation in silicon bioavailability, ranging from values below 1% up to values close to 50%, depending on the chemical form. Therefore, the aim of this study was to evaluate the scientific literature related to the different chemical forms of silicon supplements available and the limitations and recent progress in this field. According to reported studies, among the different chemical forms available, the orthosilicic acid (OSA) presents the higher bioavailability, whereas the others forms have absorption inversely proportional to the degree of polymerization. However, clinical studies evaluating safety and efficacy are still lacking. PMID:27438201

  9. Synergistic effects of ethosomes and chemical enhancers on enhancement of naloxone permeation through human skin.

    Science.gov (United States)

    Xu, D H; Zhang, Q; Feng, X; Xu, X; Liang, W Q

    2007-04-01

    The purpose of this study was to investigate the effects of ethosomes, chemical enhancers and their binary combination on the in vitro permeability enhancement of naloxone through human skin. Franz diffusion cells were used for the percutaneous absorption studies. Propylene glycol (PG), N,N-dimethyl formamide (N,N-DMF), N,N-dimethyl acetamide (N,N-DMA), dimethyl sulfoxide (DMSO), Azone and polyethylene glycol 400 (PEG400), were chosen as the chemical enhancers. Naloxone ethosomes showed 11.68 times increase in steady-state flux compared to phosphate buffered solution (PBS). Ethosomes in combination with chemical enhancers synergistically increased (p ethosomal form dramatically enhanced the skin permeation of naloxone in vitro compared with ethosomes (steady-state flux: 96.75 +/- 5.70 microg x cm(-2) x h(-1) vs 20.56 +/- 1.67 microg x cm(-2) x h(-1)). Ethosomal carrier and enhancers accumulated in the skin after 24 h were greater than that of PBS.

  10. Slit2 promotes tumor growth and invasion in chemically induced skin carcinogenesis.

    Science.gov (United States)

    Qi, Cuiling; Lan, Haimei; Ye, Jie; Li, Weidong; Wei, Ping; Yang, Yang; Guo, Simei; Lan, Tian; Li, Jiangchao; Zhang, Qianqian; He, Xiaodong; Wang, Lijing

    2014-07-01

    Slit, a neuronal guidance cue, binds to Roundabout (Robo) receptors to modulate neuronal, leukocytic, and endothelial migration. Slit has been reported to have an important effect on tumor growth and metastasis. In the current study, we evaluated the role of Slit2 in skin tumor growth and invasion in mice using a two-step chemical carcinogenesis protocol. We found that Slit2 expression correlated with the loss of basement membrane in the samples of human skin squamous cell carcinoma at different stages of disease progression. Slit2-Tg mice developed significantly more skin tumors than wild-type mice. Furthermore, the skin tumors that occurred in Slit2-Tg mice were significantly larger than those in the wild-type mice 10 weeks after 7,12-dimethylbenz[a]anthracene initiation until the end of the experiment. We also found that pathological development of the wild-type mice was delayed compared with that of Slit2-Tg mice. To further investigate the mechanism of increasing tumors in Slit2-Tg mice, we analyzed the expression of 5-bromo-2'-deoxyuridine (BrdU) in mouse skin lesions and found that the number of BrdU-positive cells and microvessel density in skin lesions were significantly higher in Slit2-Tg mice than in wild-type mice. Histological staining of PAS and type IV collagen and the colocalization of Slit2 and type IV collagen demonstrated varying degrees of loss of the basement membrane in the skin lesions from Slit2-Tg mice that were at the stage of carcinoma in situ. However, the basement membrane was well defined in the wild-type mice. In addition, MMP2, but not MMP9, was upregulated in the skin tissue of Slit2-Tg mice. Interruption of Slit2-Robo1 signaling by the antibody R5 significantly repressed the invasive capability of the squamous cell carcinoma cell line A431. Taken together, our findings reveal that Slit2 promotes DMBA/TPA-induced skin tumorigenesis by increasing cell proliferation, microvessel density, and invasive behavior of cutaneous squamous

  11. Allergic Diseases and Multiple Chemical Sensitivity in Korean Adults

    Science.gov (United States)

    Jeong, Inchul; Kim, Inah; Park, Hye Jung; Roh, Jaehoon; Park, Jung-Won

    2014-01-01

    Purpose Multiple chemical sensitivity (MCS) is a clinical syndrome representing multi-organ and psychological symptoms caused by chronic exposure to various chemicals in low concentrations. We evaluated the prevalence and related factors of MCS targeting Korean adults using the Quick Environmental Exposure and Sensitivity Inventory (QEESI©). Methods A total of 446 participants were recruited from Severance Hospital. Participants underwent a questionnaire interview including questions on sociodemographic factors, occupational and environmental factors, allergic diseases, and the QEESI©. Among them, 379 participants completed the questionnaire and the QEESI©. According to the QEESI© interpretation results, participants were divided into very suggestive (VS) group and less suggestive (LS) group. Results The estimated prevalence of MCS was higher in allergic patients than non-allergic participants (19.7% and 11.3%, respectively, P=0.04). In the multivariate logistic regression analysis, ages of 30-39 (OR, 2.94; 95% CI, 1.25-6.95) and those of 40-49 (OR, 2.51; 95% CI, 1.02-6.21) were significantly related to MCS compared to those aged less than 30 years. Female sex (OR, 2.16; 95% CI, 1.11-4.18), experience of dwelling in a new house (OR, 2.05; 95% CI, 1.04-4.03), and atopic dermatitis (OR, 1.95; 95% CI, 1.04-3.69) were also significantly related to MCS. However, only age of 30-39 in the allergic group was significant in the stratified analysis. Conclusions The estimated prevalence of MCS was higher among allergic patients than non-allergic participants. People with experience of dwelling in a new house and atopic dermatitis were more at risk of being intolerant to chemicals. Further studies to provide the nationally representative prevalence data and clarify risk factors and mechanisms of MCS are required. PMID:25228997

  12. Rat epidermal keratinocyte organotypic culture (ROC) as a model for chemically induced skin irritation testing.

    Science.gov (United States)

    Pappinen, Sari; Pasonen-Seppänen, Sanna; Suhonen, Marjukka; Tammi, Raija; Urtti, Arto

    2005-11-01

    The potential of rat epidermal keratinocyte (REK) organotypic culture (ROC) with proper stratum corneum barrier as a model for screening skin irritants was evaluated. The test chemicals were selected from ECETOC database (1995) and the observed in vitro irritation potential was compared to ECETOC in vivo primary irritation index (PII), to EU risk phrases, and to the harmonized OECD criteria. Chemicals were applied onto the stratum corneum surface of ROC for 30 min and samples were taken from the underlying medium at 4 and 8 h after exposure. Cell membrane integrity (determined by LDH assay) and pro-inflammatory effect (determined by IL-1alpha release) were verified at both time points and correlated to PII values. The best correlation (R(2) = 0.831) was seen with LDH leakage test. Based on obtained data, chemicals were classified according to criteria defined by EU and OECD. From 12 chemicals, only two were incorrectly classified according to OECD criteria when using LDH leakage and IL-1alpha release as irritation markers. At the end of experiment, chemical-treated ROC cultures were fixed and histological changes were assessed. Typical signs for irritation were lightly stained cytoplasm, condensed nuclei, cellular vacuolization, eosinophilic cytoplasms, and blebbing. These irritation effects of chemicals were graded visually into four classes (A-D). The extent of morphological perturbations of the cultures mostly correlated with PII. The present results indicate the validity of the ROC model in predicting skin irritation potential of chemicals and show that the use of set of irritation markers with different mechanistic responses gives more information on irritation than if only one marker was used.

  13. Physicochemical properties of pH-sensitive hydrogels based on hydroxyethyl cellulose-hyaluronic acid and for applications as transdermal delivery systems for skin lesions.

    Science.gov (United States)

    Kwon, Soon Sik; Kong, Bong Ju; Park, Soo Nam

    2015-05-01

    We investigated the physicochemical properties of pH-sensitive hydroxyethyl cellulose (HEC)/hyaluronic acid (HA) complex hydrogels containing isoliquiritigenin (ILTG), and discussed potential applications as transdermal delivery systems for the treatment of skin lesions caused by pH imbalance. HA has skin compatibility and pH functional groups and HEC serves as scaffold to build hydrogels with varied HCE:HA mass ratio. Hydrogels were synthesized via chemical cross-linking, and three-dimensional network structures were characterized via scanning electron microscopy (SEM). The swelling properties and polymer ratios of the hydrogels were investigated at pH values in the range 1-13. HECHA13 (i.e., an HEC:HA mass ratio of 1:3) was found to have optimal rheological and adhesive properties, and was used to investigate the drug release efficiency as a function of pH; the efficiency was greater than 70% at pH 7. Antimicrobial activity assays against Propionibacterium acnes were conducted to take advantage of the pH-sensitive properties of HECHA13. At pH 7, we found that HECHA13, which contained ILTG, inhibited the growth of P. acnes. Furthermore, HECHA13 was found to exhibit excellent permeability into the skin, which penetrated mostly via the hair follicle. These results indicate that this pH-sensitive hydrogel is effective as a transdermal delivery system for antimicrobial therapeutics, with potential applications in the treatment of acne.

  14. Assessing the sensitivity of human skin hyperspectral responses to increasing anemia severity levels

    Science.gov (United States)

    Baranoski, Gladimir V. G.; Dey, Ankita; Chen, Tenn F.

    2015-09-01

    Anemia is a prevalent medical condition that seriously affects millions of people all over the world. In many regions, not only its initial detection but also its monitoring are hindered by limited access to laboratory facilities. This situation has motivated the development of a wide range of optical devices and procedures to assist physicians in these tasks. Although noticeable progress has been achieved in this area, the search for reliable, low-cost, and risk-free solutions still continues, and the strengthening of the knowledge base about this disorder and its effects is essential for the success of these initiatives. We contribute to these efforts by closely examining the sensitivity of human skin hyperspectral responses (within and outside the visible region of the light spectrum) to reduced hemoglobin concentrations associated with increasing anemia severity levels. This investigation, which involves skin specimens with distinct biophysical and morphological characteristics, is supported by controlled in silico experiments performed using a predictive light transport model and measured data reported in the biomedical literature. We also propose a noninvasive procedure to be employed in the monitoring of this condition at the point-of-care.

  15. Assessment of skin barrier function and biochemical changes of ex vivo human skin in response to physical and chemical barrier disruption.

    Science.gov (United States)

    Döge, Nadine; Avetisyan, Araks; Hadam, Sabrina; Pfannes, Eva Katharina Barbosa; Rancan, Fiorenza; Blume-Peytavi, Ulrike; Vogt, Annika

    2016-12-21

    Topical dermatotherapy is intended to be used on diseased skin. Novel drug delivery systems even address differences between intact and diseased skin underlining the need for pre-clinical assessment of different states of barrier disruption. Herein, we studied how short-term incubation in culture media compared to incubation in humidified chambers affects human skin barrier function and viability. On both models we assessed different types and intensities of physical and chemical barrier disruption methods with regard to structural integrity, biophysical parameters and cytokine levels. Tissue degeneration and proliferative activity limited the use of tissue cultures to 48h. Viability is better preserved in cultured tissue. Tape-stripping (50×TS) and 4h sodium lauryl sulfate (SLS) pre-treatment were identified as highly reproducible and effective procedures for barrier disruption. Transepidermal water loss (TEWL) values reproducibly increased with the intensity of disruption while sebum content and skin surface pH were of limited value. Interleukin (IL)-6/8 and various chemokines and proteases were increased in tape-stripped skin which was more pronounced in SLS-treated skin tissue extracts. Thus, albeit limited to 48h, cultured full-thickness skin maintained several barrier characteristics and responded to different intensities of barrier disruption. Potentially, these models can be used to assess pre-clinically the efficacy and penetration of anti-inflammatory compounds.

  16. Sensitization to Aeroallergens in Patients with Respiratory Allergies Based on Skin-Prick Test Results

    Directory of Open Access Journals (Sweden)

    G Bejtullahu

    2012-10-01

    Full Text Available Background: The aim of this study was to identify the most common aeroallergens in patients with asthma and rhinitis.Methods: The study enrolled 102 participants including 64 patients with respiratory allergies (among them 15 were clinically diagnosed as asthma patients, 41 with rhinitis, 8 were both and 38 healthy controls. All of participants were subject of skin prick tests (SPT with series of common allergenic extracts. Sera from all participants were tested for total IgE and eosinophil count. To measure airflow limitation and reversibility in asthma patients the pulmonary function testing were carried out.Results: M/F ratio was 1:1.6 in patients and 1:0.7 in control group with mean age 28.88 year (SD 13.16; range 6 – 55year and 20.47 respectively (SD 1.16; range 19-23 year. The most common risk factors in these patients were total IgE more than 100 IU/ml, eosinophils above 4% and positive family history of atopy. Skin prick testing results showed prevalence rates for allergen groups in this manner: house dust mites 81.3 %, pollens 57.8 %, animal dandruff12.5% and moulds 4.9%. Polysensitization was common in 51.6% of all sensitized patients being positive to more than one group of allergens.Conclusion: House dust mites are the main sensitizing allergens among our allergic patients as well as healthy controls. Next in importance, in all participants, are grasses. This pattern of prevalence was expected based on herbal geography, climate and specially lifestyle. It was also compatible with the results from studies carried out in places with the same habitat.

  17. Classification of skin sensitizing substances: a comparison between approaches used by the DFG-MAK Commission and the European Union legislation.

    Science.gov (United States)

    Lessmann, H; Uter, W; Diepgen, T L; Drexler, H; Fartasch, M; Greim, H; Hartwig, A; Kreis, P; Löser, E; Merget, R; Merk, H; Nowak, D; Rothe, A; Stropp, G; Schnuch, A

    2011-10-01

    A systematic classification of substances (or mixtures of substances) with regard to various toxicological endpoints is a prerequisite for the implementation of occupational safety strategies. As its principal task the "Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area" of the "Deutsche Forschungsgemeinschaft" (DFG-MAK Commission) derives and recommends maximum workplace concentrations and biological tolerance values (MAK and BAT values) based exclusively on scientific arguments. Several endpoints are evaluated separately in detail, e.g. carcinogenicity, risks during pregnancy, germ cell mutagenicity or contribution to systemic toxicity after cutaneous absorption. Skin- and airway sensitization is also considered; the present paper focuses on these two endpoints.

  18. Efficacy of the combined use of a facial cleanser and moisturizers for the care of mild acne patients with sensitive skin.

    Science.gov (United States)

    Isoda, Kenichi; Seki, Tsuyoshi; Inoue, Yosuke; Umeda, Koji; Nishizaka, Takahiro; Tanabe, Hisateru; Takagi, Yutaka; Ishida, Koichi; Mizutani, Hitoshi

    2015-02-01

    Acne is a common skin disease that involves the seborrheic area of the face and results from the obstruction of hair follicles followed by inflammation. Careful face washing helps to improve and prevent acne; however, intensive washing has a risk of inducing skin barrier impairment and dry skin, especially in sensitive skin. We hypothesized that skin care combining mild skin cleansing and intensive moisturizing ("combination skin care") may be effective in the care of acne in subjects with dry skin and/or sensitive skin. We developed a combination skin care with a weakly acidic foaming facial skin cleanser based on a mild detergent, an aqueous lotion with eucalyptus extract and a moisturizing gel containing pseudo-ceramide and eucalyptus extract. To optimize an ideal facial skin care system for mild acne on sensitive skin, we performed a 4-week clinical trial with 29 post-adolescent Japanese women with mild acne with dry and sensitive skin. The acne significantly decreased after this trial accompanied by the improvement of dry skin, a significantly increased endogenous ceramide level in the stratum corneum and an elongated alkyl chain length of the non-hydroxy acyl sphingosine type ceramide. No adverse events due to the test samples were observed. Based on diagnosis by a dermatologist, 97% of the subjects found the combination skin care to be "useful" or "slightly useful". Based on these findings, the combined use of a facial skin cleanser and moisturizers is safe and effective for the care of acne in post-adolescent Japanese women with sensitive skin.

  19. Influence of heredity on human sensitivity to environmental chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Weber, W.W. [Univ. of Michigan, Ann Arbor, MI (United States)

    1995-12-31

    Hereditary peculiarities in individual responses to environmental chemicals are a common occurrence in human populations. Genetic variation in glutathione S-transferase, CYP1A2, N-acetyltransferase, and paraoxonase exemplify the relationship of metabolic variation to individual susceptibility to cancer and other toxicants of environmental origin. Heritable receptor protein variants, a subset of proteins of enormous pharmacogenetic, potential that have not thus far been extensively explored form the pharmacogenetic standpoint, and also considered. Examples of interest that are considered include receptor variants associated with retinoic acid resistance in acute promyelocytic leukemia, with paradoxical responses to antiandrogens in prostate cancer, and with retinitis pigmentosa. Additional heritable protein variants of pharmacogenetic interest that result in antibiotic-induced deafness, glucocorticoid-remediable aldosteronism and hypertension, the long-QT syndrome, and beryllium-induced lung disease are also discussed. These traits demonstrate how knowledge of the molecular basis and mechanism of the variant response may contribute to its prevention in sensitive persons as well as to improved therapy for genetically conditioned disorders that arise form environmental chemicals. 99 refs.

  20. Multiple chemical sensitivity and idiopathic environmental intolerance (part one).

    Science.gov (United States)

    Watanabe, Mitsuyasu; Tonori, Hideki; Aizawa, Yoshiharu

    2003-01-01

    Multiple chemical sensitivity/idiopathic environmental intolerance (MCS/IEI) is a commonly used diagnostic term for a group of symptoms. These symptoms have been described and commented on for more than 15 years in the USA. Recently, it has also been observed in Japan. The main features of this syndrome are multiple symptoms involving in multiple organ systems that are precipitated by a variety of chemical substances with relapses and exacerbation under certain conditions when exposed to very low levels which do not affect the population at large. There are no laboratory markers or specific investigative findings. Although traditional medical organizations have not agreed on a definition for this syndrome due to the lack of obvious evidence to demonstrate the existence of these symptoms, it is being increasingly recognized. It constitutes an increasing percentage of the caseload at occupational/environmental medical clinics.Part one of this review article discusses pathophysiological theories, substances which cause symptoms, prevalence in the general and specific populations, past history and family history, and clinical symptoms of MCS/IEI patients.

  1. Sensitivity study of SMILES-2 for chemical species

    Science.gov (United States)

    Suzuki, Makoto; Manago, Naohiro; Ozeki, Hiroyuki; Ochiai, Satoshi; Baron, Philippe

    2015-10-01

    Sensitivity studies of temperature and chemical species (Observed by ISS/JEM/SMILES: O3, HCl, ClO, HO2, BrO, HNO3, CH3CN, and Not observed by SMILES: Temperature, H2O, N2O, NO2, NO, CH3Cl, CO, H2CO, OH and O-atom) was carried out for the SMILES-2 proposal, a sub-mm and THz observation of limb emission from space over the spectral region from 400 GHz to 2.5 THz. Tentative but optimal candidate of frequency bands to cover these species was selected with 3 SIS (Superconductor-Insulator-Superconductor) mixers; SIS-1 (485-489 GHz + 523-527 GHz), SIS-2 (623-627 GHz + 648-652 GHz), SIS-3 (557 GHz + 576.3 GHz) and 2 HEB (Hot Electron Bolometer); HEB-1 (1.8 THz OH) and HEB-2 (2.06 THz O-atom). Temperature can be retrieved with 1 K precision and 1 km vertical resolution from 15 to 120 km. Other chemical species also showed very high single scan precision (random error) comparable to statistical standard error of previous satellite measurements.

  2. Optimization of a chemical method for skinning of sardines (Sardina pilchardus during canning processing

    Directory of Open Access Journals (Sweden)

    Manuela Vaz Velho

    2014-06-01

    Full Text Available Most of sardine (Sardina pilchardus catches is used for canning purposes. The most common product presentation is a beheaded sardine with skin and bones packed in a tin can. Canned sardines can also be presented skinless and boneless. For this last type of product, after beheading and evisceration, sardines are placed in trays, cooked and then skinned by hand, one by one, and placed in the tins, a process involving high labour costs. The aim of this work was to develop a chemical process for peeling raw sardines and its subsequent application in a canning industry processing line just after the beheading and evisceration step and before cooking. Potassium hydroxide treatments (pellets a.r. 85% KOH were applied at concentrations of 2, 3 and 4% (v/v, distilled water. Frozen sardines were beheaded and eviscerated after thawing and immersed in the different potassium hydroxide solutions at 93ºC (pH respectively 13, 13 and 13.02 for 3 min and further washed with distilled water at 100°C. In this first set of experiments, fat sardines were used (average of 9.86% of fat, w/w. The best performance, with respect to skin removal, was achieved with the 2% potassium hydroxide immersion (pH 13. With this treatment the skin was totally removed after immersion. With the other tested concentrations portions of skin were always visible and in some cases changes in texture with breakdown of muscle structure and changes of colour occurred. It was decided to perform a second set of experiments using the 2% KOH treatment, but this time applied to low fat sardines (average of 4.77% of fat, w/w, following the same subsequent procedures. The results showed that the lower fat sardines are more prone to surface changes of colour and major muscle breaks than fat sardines after the potassium hydroxide treatment. In the canning industry for this type of product (skinless and boneless only fat sardines are used to assure the total removal of skin. This treatment of 2% KOH

  3. Skin irritation: prevalence, variability, and regulatory classification of existing in vivo data from industrial chemicals.

    Science.gov (United States)

    Hoffmann, Sebastian; Cole, Thomas; Hartung, Thomas

    2005-04-01

    In vivo rabbit data for skin irritation registered in the European New Chemicals Database (NCD) and an ECETOC Database were evaluated to characterise the distribution of irritation potential among chemicals and to assess the variability of the animal test. These databases could be used to determine experimental and rudimentarily within-laboratory variability, but not between-laboratory variability. Our evaluation suggests that experimental variability is small. Using two classification systems--the system currently used in Europe and the Globally Harmonised System (GHS)--the prevalence of skin irritation data obtained from NCD was analysed. This analysis revealed that out of 3121 chemicals tested, less than 10% showed an irritation potential in rabbits which would require an appropriate hazard label and 64% did not cause any irritation. Furthermore, it appears that in practical use the European classification system introduces bias towards overclassification. Based on these findings, we conclude, that the classification systems should be refined taking prevalence into account. Additionally, prevalence should be incorporated into the design and analysis of validation studies for in vitro test methods and in the definition of testing strategies.

  4. Chemical kinetics of multiphase reactions between ozone and human skin lipids: Implications for indoor air quality and health effects.

    Science.gov (United States)

    Lakey, P S J; Wisthaler, A; Berkemeier, T; Mikoviny, T; Pöschl, U; Shiraiwa, M

    2016-12-10

    Ozone reacts with skin lipids such as squalene, generating an array of organic compounds, some of which can act as respiratory or skin irritants. Thus, it is important to quantify and predict the formation of these products under different conditions in indoor environments. We developed the kinetic multilayer model that explicitly resolves mass transport and chemical reactions at the skin and in the gas phase (KM-SUB-Skin). It can reproduce the concentrations of ozone and organic compounds in previous measurements and new experiments. This enabled the spatial and temporal concentration profiles in the skin oil and underlying skin layers to be resolved. Upon exposure to ~30 ppb ozone, the concentrations of squalene ozonolysis products in the gas phase and in the skin reach up to several ppb and on the order of ~10 mmol m(-3) . Depending on various factors including the number of people, room size, and air exchange rates, concentrations of ozone can decrease substantially due to reactions with skin lipids. Ozone and dicarbonyls quickly react away in the upper layers of the skin, preventing them from penetrating deeply into the skin and hence reaching the blood.

  5. What Happens after Activation of Ascaridole? Reactive Compounds and Their Implications for Skin Sensitization.

    Science.gov (United States)

    Chittiboyina, Amar G; Avonto, Cristina; Khan, Ikhlas A

    2016-09-19

    To replace animal testing and improve the prediction of skin sensitization, significant attention has been directed to the use of alternative methods. The direct peptide reactivity assay (DPRA), the regulatory agencies' approved alternative in chemico method, has been applied for understanding the sensitization capacity of activated ascaridole. Ascaridole, the oxidative metabolite of α-terpinene, is considered to be one of the components responsible for the contact allergy associated with essential oils derived from Chenopodium and Melaleuca species. The recently developed high-throughput screening based on the dansyl cysteamine (HTS-DCYA) method was applied to understand the reported enhanced reactivity of activated ascaridole and possibly to identify the resulting elusive radical or other reactive species. For the first time, a substituted cyclohexenone was identified as a potential electrophilic intermediate resulting in higher depletion of nucleophilic DCYA, along with several nonreactive byproducts of ascaridole via a radical degradation mechanism. Formation of electrophilic species via radical degradation is one of the possible pathways should be considered for the peptide reactivity of in aged tea tree oil or oils rich in terpinenes along with commonly believed reactants, allylic-epoxides and allylic-peroxides.

  6. Development, fabrication, and modeling of highly sensitive conjugated polymer based piezoresistive sensors in electronic skin applications

    Science.gov (United States)

    Khalili, Nazanin; Naguib, Hani E.; Kwon, Roy H.

    2016-04-01

    Human intervention can be replaced through development of tools resulted from utilizing sensing devices possessing a wide range of applications including humanoid robots or remote and minimally invasive surgeries. Similar to the five human senses, sensors interface with their surroundings to stimulate a suitable response or action. The sense of touch which arises in human skin is among the most challenging senses to emulate due to its ultra high sensitivity. This has brought forth novel challenging issues to consider in the field of biomimetic robotics. In this work, using a multiphase reaction, a polypyrrole (PPy) based hydrogel is developed as a resistive type pressure sensor with an intrinsically elastic microstructure stemming from three dimensional hollow spheres. Furthermore, a semi-analytical constriction resistance model accounting for the real contact area between the PPy hydrogel sensors and the electrode along with the dependency of the contact resistance change on the applied load is developed. The model is then solved using a Monte Carlo technique and the sensitivity of the sensor is obtained. The experimental results showed the good tracking ability of the proposed model.

  7. KCNQ Potassium Channels Modulate Sensitivity of Skin Down-hair (D-hair) Mechanoreceptors.

    Science.gov (United States)

    Schütze, Sebastian; Orozco, Ian J; Jentsch, Thomas J

    2016-03-11

    M-current-mediating KCNQ (Kv7) channels play an important role in regulating the excitability of neuronal cells, as highlighted by mutations in Kcnq2 and Kcnq3 that underlie certain forms of epilepsy. In addition to their expression in brain, KCNQ2 and -3 are also found in the somatosensory system. We have now detected both KCNQ2 and KCNQ3 in a subset of dorsal root ganglia neurons that correspond to D-hair Aδ-fibers and demonstrate KCNQ3 expression in peripheral nerve endings of cutaneous D-hair follicles. Electrophysiological recordings from single D-hair afferents from Kcnq3(-/-) mice showed increased firing frequencies in response to mechanical ramp-and-hold stimuli. This effect was particularly pronounced at slow indentation velocities. Additional reduction of KCNQ2 expression further increased D-hair sensitivity. Together with previous work on the specific role of KCNQ4 in rapidly adapting skin mechanoreceptors, our results show that different KCNQ isoforms are specifically expressed in particular subsets of mechanosensory neurons and modulate their sensitivity directly in sensory nerve endings.

  8. Thresholds of skin sensitivity are partially influenced by mechanical properties of the skin on the foot sole

    OpenAIRE

    Strzalkowski, Nicholas D J; Triano, John J; Lam, Chris K; Templeton, Cale A; Bent, Leah R

    2015-01-01

    Across the foot sole, there are vibration and monofilament sensory differences despite an alleged even distribution of cutaneous afferents. Mechanical property differences across foot sole sites have been proposed to account for these differences. Vibration (VPT; 3 Hz, 40 Hz, 250 Hz), and monofilament (MF) perception threshold measurements were compared with skin hardness, epidermal thickness, and stretch response across five foot sole locations in young healthy adults (n = 22). Perceptual th...

  9. Comprehensive Monte-Carlo simulator for optimization of imaging parameters for high sensitivity detection of skin cancer at the THz

    Science.gov (United States)

    Ney, Michael; Abdulhalim, Ibrahim

    2016-03-01

    Skin cancer detection at its early stages has been the focus of a large number of experimental and theoretical studies during the past decades. Among these studies two prominent approaches presenting high potential are reflectometric sensing at the THz wavelengths region and polarimetric imaging techniques in the visible wavelengths. While THz radiation contrast agent and source of sensitivity to cancer related tissue alterations was considered to be mainly the elevated water content in the cancerous tissue, the polarimetric approach has been verified to enable cancerous tissue differentiation based on cancer induced structural alterations to the tissue. Combining THz with the polarimetric approach, which is considered in this study, is examined in order to enable higher detection sensitivity than previously pure reflectometric THz measurements. For this, a comprehensive MC simulation of radiative transfer in a complex skin tissue model fitted for the THz domain that considers the skin`s stratified structure, tissue material optical dispersion modeling, surface roughness, scatterers, and substructure organelles has been developed. Additionally, a narrow beam Mueller matrix differential analysis technique is suggested for assessing skin cancer induced changes in the polarimetric image, enabling the tissue model and MC simulation to be utilized for determining the imaging parameters resulting in maximal detection sensitivity.

  10. Sensitization to Food Additives in Patients with Allergy: A Study Based on Skin Test and Open Oral Challenge.

    Science.gov (United States)

    Moghtaderi, Mozhgan; Hejrati, Zinatosadat; Dehghani, Zahra; Dehghani, Faranak; Kolahi, Niloofar

    2016-06-01

    There has been a great increase in the consumption of various food additives in recent years. The purpose of this study was to identify the incidence of sensitization to food additives by using skin prick test in patients with allergy and to determine the concordance rate between positive skin tests and oral challenge in hypersensitivity to additives. This cross-sectional study included 125 (female 71, male 54) patients aged 2-76 years with allergy and 100 healthy individuals. Skin tests were performed in both patient and control groups with 25 fresh food additives. Among patients with allergy, 22.4% showed positive skin test at least to one of the applied materials. Skin test was negative to all tested food additives in control group. Oral food challenge was done in 28 patients with positive skin test, in whom 9 patients showed reaction to culprit (Concordance rate=32.1%). The present study suggested that about one-third of allergic patients with positive reaction to food additives showed positive oral challenge; it may be considered the potential utility of skin test to identify the role of food additives in patients with allergy.

  11. Assessment of a new questionnaire for self-reported sun sensitivity in an occupational skin cancer screening program

    Directory of Open Access Journals (Sweden)

    Steinebrunner Beatrix

    2008-10-01

    Full Text Available Abstract Background Sun sensitivity of the skin is a risk factor for the development of cutaneous melanoma and other skin cancers. Epidemiological studies on causal factors for the development of melanoma must control for sun sensitivity as a confounder. A standardized instrument for measuring sun sensitivity has not been established yet. It is assumed that many studies show a high potential of residual confounding for sun sensitivity. In the present study, a new questionnaire for the assessment of self-reported sun sensitivity is administered and examined. Methods Prior to an occupational skin cancer screening program, the 745 participating employees were asked to fill in a questionnaire for self-assessment of sun sensitivity. The questionnaire was developed by experts of the working group "Round Table Sunbeds" (RTS to limit the health hazards of sunbed use in Germany. A sun sensitivity score (RTS-score was calculated using 10 indicators. The internal consistency of the questionnaire and the agreement with other methods (convergent validity were examined. Results The RTS-score was calculated for 655 study participants who were 18 to 65 years of age. The correlation of the items among each other was between 0.12 and 0.62. The items and the RTS-score correlated between 0.46 and 0.77. The internal consistency showed a reliability coefficient with 0.82 (Cronbach's alpha. The comparison with the Fitzpatrick classification, the prevailing standard, was possible in 617 cases with a rank correlation of rs = 0.65. The categorization of the RTS-score in four risk groups showed correct classification to the four skin types of Fitzpatrick in 75% of the cases. Other methods for the assessment of sun sensitivity displayed varying agreements with the RTS-score. Conclusion The RTS questionnaire showed a sufficient internal consistency. There is a good convergent validity between the RTS-score and the Fritzpatrick classification avoiding shortcomings of the

  12. [Multiple chemical sensitivity: a diagnosis not to be missed].

    Science.gov (United States)

    Dupas, D; Dagorne, M-A

    2013-02-01

    Multiple chemical sensitivity (MCS) is a chronic condition, which belongs to the group of medically unexplained syndromes. Patients (men as well as women) complain of many subjective symptoms such as nose and mouth irritation, sore throat, dyspnea, tiredness, dizziness, headache and concentration difficulties. Patient typically report at least four or five symptoms occurring when they are exposed to particular substances, at a very low concentration that usually does not cause symptoms or harm in normal individuals. The common feature of products that appear to be responsible (either occupational or domestic) is that they have a strong smell and include: solvent, paint, glue, tar, oil, pesticides, perfume, cosmetics and spray products. MCS is nowadays considered to be one aspect of idiopathic environmental intolerance (IEI) whose other main aspect is hypersensitivity to electromagnetic fields. If the diagnosis is suspected clinically it can be confirmed using the Quick Environmental Exposure and Sensitivity Inventory (QEESI(©)) self-questionnaire. MCS is often misdiagnosed as asthma or an allergic conditions which means that patients are frequently referred to respiratory and allergy specialists. Misdiagnosis can lead to many futile medical investigations. Psychotherapy can improve quality of life in some cases. Preventive measures are often ineffective and do not stop the condition worsening: hypersensitivity can spread to common environmental odors so that a few people become severely disabled and limited in their workplace as well as in private life. In France, 435 cases were registered in the university hospital occupational disease departments network (RNV3P) during the period 2007-2010. It is therefore important that every clinician be able to recognize the condition and ensure that their patients could get compensation when unable to go on working.

  13. Open source software implementation of an integrated testing strategy for skin sensitization potency based on a Bayesian network.

    Science.gov (United States)

    Pirone, Jason R; Smith, Marjolein; Kleinstreuer, Nicole C; Burns, Thomas A; Strickland, Judy; Dancik, Yuri; Morris, Richard; Rinckel, Lori A; Casey, Warren; Jaworska, Joanna S

    2014-01-01

    An open-source implementation of a previously published integrated testing strategy (ITS) for skin sensitization using a Bayesian network has been developed using R, a free and open-source statistical computing language. The ITS model provides probabilistic predictions of skin sensitization potency based on in silico and in vitro information as well as skin penetration characteristics from a published bioavailability model (Kasting et al., 2008). The structure of the Bayesian network was designed to be consistent with the adverse outcome pathway published by the OECD (Jaworska et al., 2011, 2013). In this paper, the previously published data set (Jaworska et al., 2013) is improved by two data corrections and a modified application of the Kasting model. The new data set implemented in the original commercial software package and the new R version produced consistent results. The data and a fully documented version of the code are publicly available (http://ntp.niehs.nih.gov/go/its).

  14. Long-term repeatability of the skin prick test is high when supported by history or allergen-sensitivity tests

    DEFF Research Database (Denmark)

    Bødtger, Uffe; Jacobsen, C R; Poulsen, L K;

    2003-01-01

    BACKGROUND: Long-term reproducibility of the skin-prick test (SPT) has been questioned. The aim of the study was to investigate the clinical relevance of SPT changes. METHODS: SPT to 10 common inhalation allergens was performed annually from 1999 to 2001 in 25 nonsensitized and 21 sensitized...

  15. Relationships between Irritable Bowel Syndrome Pain, Skin Temperature Indices of Autonomic Dysregulation, and Sensitivity to Thermal Cutaneous Stimulation

    Directory of Open Access Journals (Sweden)

    Fong Wong

    2010-01-01

    Full Text Available This study evaluated relationships between irritable bowel syndrome (IBS pain, sympathetic dysregulation, and thermal pain sensitivity. Eight female patients with diarrhea-predominant IBS and ten healthy female controls were tested for sensitivity to thermal stimulation of the left palm. A new method of response-dependent thermal stimulation was used to maintain pain intensity at a predetermined level (35% by adjusting thermal stimulus intensity as a function of pain ratings. Clinical pain levels were assessed prior to each testing session. Skin temperatures were recorded before and after pain sensitivity testing. The temperature of palmar skin dropped (1.5∘C when the corresponding location on the opposite hand of control subjects was subjected to prolonged thermal stimulation, but this response was absent for IBS pain patients. The patients also required significantly lower stimulus temperatures than controls to maintain a 35% pain rating. Baseline skin temperatures of patients were significantly correlated with thermode temperatures required to maintain 35% pain ratings. IBS pain intensity was not significantly correlated with skin temperature or pain sensitivity. The method of response-dependent stimulation revealed thermal hyperalgesia and increased sympathetic tone for chronic pain patients, relative to controls. Similarly, a significant correlation between resting skin temperatures and thermal pain sensitivity for IBS but not control subjects indicates that tonic sympathetic activation and a thermal hyperalgesia were generated by the chronic presence of visceral pain. However, lack of a significant relationship between sympathetic tone and ratings of IBS pain casts doubt on propositions that the magnitude of IBS pain is determined by psychological stress.

  16. Two-tiered keratinocyte assay: IL-18 production by NCTC2544 cells to determine the skin sensitizing capacity and an epidermal equivalent assay to determine sensitizer potency

    DEFF Research Database (Denmark)

    Teunis, Marc; Corsini, Emanuela; Smits, Mieke;

    2012-01-01

    At present, the identification of potentially sensitizing chemicals is carried out using animal models. However, it should be very important, both from ethical and economic point of view, to discriminate allergy and irritation events, and to classify sensitizers according to their potency, without......2544 IL-18 assay can be used to identify the sensitizing capacity of a chemical (NCTC assay, tier 1) while the Epidermal Equivalent potency assay is used to quantify the potency of the sensitizing agent (EE assay, tier 2). These assays combined, may offer an unique opportunity to provide an alternative...

  17. Optimization of spectral sensitivities of mosaic five-band camera for estimating chromophore densities from skin images including shading and surface reflections

    Science.gov (United States)

    Hirose, Misa; Akaho, Rina; Maita, Chikashi; Sugawara, Mai; Tsumura, Norimichi

    2016-06-01

    In this paper, the spectral sensitivities of a mosaic five-band camera were optimized using a numerical skin phantom to perform the separation of chromophore densities, shading and surface reflection. To simulate the numerical skin phantom, the spectral reflectance of skin was first calculated by Monte Carlo simulation of photon migration for different concentrations of melanin, blood and oxygen saturation levels. The melanin and hemoglobin concentration distributions used in the numerical skin phantom were obtained from actual skin images by independent component analysis. The calculated components were assigned as concentration distributions. The spectral sensitivities of the camera were then optimized using a nonlinear technique to estimate the spectral reflectance for skin separation. In this optimization, the spectral sensitivities were assumed to be normally distributed, and the sensor arrangement was identical to that of a conventional mosaic five-band camera. Our findings demonstrated that spectral estimation could be significantly improved by optimizing the spectral sensitivities.

  18. The Iowa follow-up of chemically sensitive persons.

    Science.gov (United States)

    Black, D W; Okiishi, C; Schlosser, S

    2001-03-01

    Clinical symptoms and self-reported health status in persons reporting multiple chemical sensitivities (MCS) are presented from a 9-year follow-up study. Eighteen (69%) subjects from a sample of 26 persons originally interviewed in 1988 were followed up in 1997 and given structured interviews and self-report questionnaires. In terms of psychiatric diagnosis, 15 (83%) met DSM-IV criteria for a lifetime mood disorder, 10 (56%) for a lifetime anxiety disorder, and 10 (56%) for a lifetime somatoform disorder. Seven (39%) of subjects met criteria for a personality disorder using the Personality Diagnostic Questionnaire-IV. Self-report data from the Illness Behavior Questionnaire and Symptom Checklist-90-Revised show little change from 1988. The 10 most frequent complaints attributed to MCS were headache, memory loss, forgetfulness, sore throat, joint aches, trouble thinking, shortness of breath, back pain, muscle aches, and nausea. Global assessment showed that 2 (11%) had "remitted", 8 (45%) were "much" or "very much" improved, 6 (33%) were "improved", and 2 (11%) were "unchanged/worse". Mean scores on the SF-36 health survey showed that, compared to U.S. population means, subjects reported worse physical functioning, more bodily pain, worse general health, worse social functioning, and more emotional-role impairment; self-reported mental health was better than the U.S. population mean. All subjects maintained a belief that they had MCS; 16 (89%) acknowledged that the diagnosis was controversial. It is concluded that the subjects remain strongly committed to their diagnosis of MCS. Most have improved since their original interview, but many remain symptomatic and continue to report ongoing lifestyle changes.

  19. Allergological and Toxicological Aspects in a Multiple Chemical Sensitivity Cohort

    Directory of Open Access Journals (Sweden)

    Paolo D. Pigatto

    2013-01-01

    Full Text Available Background. Multiple chemical sensitivity (MCS is a chronic condition characterized by an exaggerated response to toxicants. We ascertained the prevalence of allergy to metals and toxicological aspects in MCS patients. Methods. We conducted a retrospective review of medical records of 41 patients with MCS. We performed patch testing (n=21 for dental series and did lymphocyte transformation test (n=18 for metals. We measured mercury in samples of blood (n=19, urine (n=19, saliva (n=20, and scalp hair (n=17 to investigate the association between mercury levels and cases of MCS. Results. The prevalence of metal immune hypersensitivity in a subset of 26 patients was 92.3 percent. Elevations of mercury occurred in 81.2 percent (26 of 32. The mean (±SD in blood concentrations of mercury was 7.6±13.6 μg/L; mean in urine was 1.9±2.5 μg/L; mean in scalp hair was 2.2±2.5 μg/g; mean in saliva was 38.1±52.1 μg/L. Subgroup analyses showed that elevation of mercury levels in biological matrices were associated with mercury amalgams in patients with MCS (22 patients, compared with controls (8 patients (odds ratio 11 : 95 percent confidence interval 1.5 to 81.6; P=0.023. Conclusions. Our data show an increased prevalence of metal allergy and elevation of mercury levels in bioindicators among patients with MCS.

  20. Non-allergic cutaneous reactions in airborne chemical sensitivity--a population based study.

    Science.gov (United States)

    Berg, Nikolaj Drimer; Linneberg, Allan; Thyssen, Jacob Pontoppidan; Dirksen, Asger; Elberling, Jesper

    2011-06-01

    Multiple chemical sensitivity (MCS) is characterised by adverse effects due to exposure to low levels of chemical substances. The aetiology is unknown, but chemical related respiratory symptoms have been found associated with positive patch test. The purpose of this study was to investigate the relationship between cutaneous reactions from patch testing and self-reported severity of chemical sensitivity to common airborne chemicals. A total of 3460 individuals participating in a general health examination, Health 2006, were patch tested with allergens from the European standard series and screened for chemical sensitivity with a standardised questionnaire dividing the participants into four severity groups of chemical sensitivity. Both allergic and non-allergic cutaneous reactions--defined as irritative, follicular, or doubtful allergic reactions--were analysed in relationship with severity of chemical sensitivity. Associations were controlled for the possible confounding effects of sex, age, asthma, eczema, atopic dermatitis, psychological and social factors, and smoking habits. In unadjusted analyses we found associations between allergic and non-allergic cutaneous reactions on patch testing and the two most severe groups of self-reported sensitivity to airborne chemicals. When adjusting for confounding, associations were weakened, and only non-allergic cutaneous reactions were significantly associated with individuals most severely affected by inhalation of airborne chemicals (odds ratio = 2.5, p = 0.006). Our results suggest that individuals with self-reported chemical sensitivity show increased non-allergic cutaneous reactions based on day 2 readings of patch tests.

  1. Transfer of a two-tiered keratinocyte assay: IL-18 production by NCTC2544 to determine the skin sensitizing capacity and epidermal equivalent assay to determine sensitizer potency

    DEFF Research Database (Denmark)

    Teunis, Marc; Corsini, Emanuela; Smits, Mieke;

    2013-01-01

    At present, the identification of potentially sensitizing chemicals is carried out using animal models. However, it is very important from ethical, safety and economic point of view to have biological markers to discriminate allergy and irritation events, and to be able to classify sensitizers...

  2. Non-allergic cutaneous reactions in airborne chemical sensitivity--a population based study

    DEFF Research Database (Denmark)

    Linneberg, Allan; Thyssen, Jacob Pontoppidan; Dirksen, Asger

    2011-01-01

    the relationship between cutaneous reactions from patch testing and self-reported severity of chemical sensitivity to common airborne chemicals. A total of 3460 individuals participating in a general health examination, Health 2006, were patch tested with allergens from the European standard series and screened...... for chemical sensitivity with a standardised questionnaire dividing the participants into four severity groups of chemical sensitivity. Both allergic and non-allergic cutaneous reactions--defined as irritative, follicular, or doubtful allergic reactions--were analysed in relationship with severity of chemical...... most severe groups of self-reported sensitivity to airborne chemicals. When adjusting for confounding, associations were weakened, and only non-allergic cutaneous reactions were significantly associated with individuals most severely affected by inhalation of airborne chemicals (odds ratio = 2.5, p = 0...

  3. Imaging of skin birefringence for human scar assessment using polarization-sensitive optical coherence tomography aided by vascular masking

    Science.gov (United States)

    Gong, Peijun; Chin, Lixin; Es'haghian, Shaghayegh; Liew, Yih Miin; Wood, Fiona M.; Sampson, David D.; McLaughlin, Robert A.

    2014-12-01

    We demonstrate the in vivo assessment of human scars by parametric imaging of birefringence using polarization-sensitive optical coherence tomography (PS-OCT). Such in vivo assessment is subject to artifacts in the detected birefringence caused by scattering from blood vessels. To reduce these artifacts, we preprocessed the PS-OCT data using a vascular masking technique. The birefringence of the remaining tissue regions was then automatically quantified. Results from the scars and contralateral or adjacent normal skin of 13 patients show a correspondence of birefringence with scar type: the ratio of birefringence of hypertrophic scars to corresponding normal skin is 2.2±0.2 (mean±standard deviation), while the ratio of birefringence of normotrophic scars to normal skin is 1.1±0.4. This method represents a new clinically applicable means for objective, quantitative human scar assessment.

  4. Knockdown of Filaggrin Impairs Diffusion Barrier Function and Increases UV Sensitivity in a Human Skin Model

    NARCIS (Netherlands)

    M. Mildner; J. Jin; L. Eckhart; S. Kezic; F. Gruber; C. Barresi; C. Stremnitzer; M. Buchberger; V. Mlitz; C. Ballaun; B. Sterniczky; D. Födinger; E. Tschachler

    2010-01-01

    Loss-of-function mutations in the filaggrin gene are associated with ichthyosis vulgaris and atopic dermatitis. To investigate the impact of filaggrin deficiency on the skin barrier, filaggrin expression was knocked down by small interfering RNA (siRNA) technology in an organotypic skin model in vit

  5. The ECVAM international validation study on in vitro tests for acute skin irritation: selection of test chemicals.

    Science.gov (United States)

    Eskes, Chantra; Cole, Thomas; Hoffmann, Sebastian; Worth, Andrew; Cockshott, Amanda; Gerner, Ingrid; Zuang, Valérie

    2007-12-01

    The ECVAM-funded skin irritation validation study (SIVS) was initiated in 2003, with the aim to evaluate whether the EpiDerm, EPISKIN and the SIFT alternative methods were able to reliably identify skin irritant and non-irritant chemicals, and could therefore be candidates for replacing the rabbit Draize test for skin irritation. The primary goal of the study was to evaluate the predictive capacity of the assays with regard to the EU classification system, which employs the risk phrases, "R38", for skin irritants, and "no label" for non-irritants. A secondary objective was the retrospective analysis of the data, to assess whether the in vitro tests would be able to discriminate between strong irritants (category 2), mild irritants (category 3) and non-irritants (no category), as defined by the OECD and United Nations proposal for a Globally Harmonised System (GHS) for the classification and labelling of dermal irritancy. A Chemicals Selection Sub-Committee (CSSC) was appointed to identify test chemicals to be used in the SIVS, for which existing, high quality in vivo data were available, with which to correlate the in vitro measurements. Since chemicals from the European Centre for the Ecotoxicology and Toxicology of Chemicals (ECETOC) database of reference chemicals for skin irritation/skin corrosion had been extensively used in preceding studies, the CSSC made use of novel sources for potential test chemicals. The first source of chemicals screened was the New Chemicals Database (NCD), which is the central archive within the EU notification scheme for 'new' commercial chemicals. Data registered in the NCD originate from standard assays, submitted in compliance with the legislation which regulates the marketing of industrial chemicals, and are subject to quality assurance by the competent authorities of the EU Member States. In addition, to obtain 'existing' chemicals which were readily available from major manufacturing and/or distribution sources, additional

  6. GA(2)LEN skin test study II: clinical relevance of inhalant allergen sensitizations in Europe

    DEFF Research Database (Denmark)

    Burbach, G J; Heinzerling, L M; Edenharter, G

    2009-01-01

    the clinical relevance of positive skin prick test reactions against inhalant allergens considering the predominating type of symptoms in a pan-European population of patients presenting with suspected allergic disease. METHODS: Clinical relevance of skin prick tests was recorded with regard to patient history...... the clinical relevance of positive skin prick tests and calls for further studies, which may, ultimately, help increase the positive predictive value of allergy testing.......BACKGROUND: Skin prick testing is the standard for diagnosing IgE-mediated allergies. A positive skin prick reaction, however, does not always correlate with clinical symptoms. A large database from a Global Asthma and Allergy European Network (GA(2)LEN) study with data on clinical relevance...

  7. Murine bone marrow-derived dendritic cells as a potential in vitro model for predictive identification of chemical sensitizers.

    Science.gov (United States)

    Pépin, Elsa; Goutet, Michèle; Ban, Masarin

    2007-12-10

    The identification of potential sensitizing chemicals is a key step in the safety assessment process. To this end, predictive tests that require no or few animals and that are reliable, inexpensive and easy to perform are needed. The aim of this study was to evaluate the performance of murine bone marrow-derived dendritic cells (BMDCs) in an in vitro skin sensitization model. BMDCs were exposed to six well-known allergens (dinitrochlorobenzene, DNCB; dinitrofluorobenzene, DNFB; Bandrowski's base, BB; paraphenylenediamine, PPD; nickel sulfate, NiSO(4); cinnamaldehyde, Cinn). Surface expression of MHC class II, CD40, CD54, and CD86 was measured by flow cytometry after 48h exposure to these chemicals. All the allergens tested induced a significant increase in marker expression, with an augmentation in the percentage of mature cells ranging from 2.3- to 10.5-fold change over control. The level of up-regulation was dependent on the concentration and the strength of the allergens. In contrast, the irritants (sodium dodecyl sulfate, SDS and 4-aminobenzoic acid, pABA) and the negative control (zinc sulfate, ZnSO(4)) tested induced either no modification or a down-regulation of membrane marker expression. Taken together, our data suggest that murine BMDCs may represent a new and valuable in vitro model to predict the sensitizing properties of chemicals.

  8. An electrically and mechanically self-healing composite with pressure- and flexion-sensitive properties for electronic skin applications

    Science.gov (United States)

    Tee, Benjamin C.-K.; Wang, Chao; Allen, Ranulfo; Bao, Zhenan

    2012-12-01

    Pressure sensitivity and mechanical self-healing are two vital functions of the human skin. A flexible and electrically conducting material that can sense mechanical forces and yet be able to self-heal repeatably can be of use in emerging fields such as soft robotics and biomimetic prostheses, but combining all these properties together remains a challenging task. Here, we describe a composite material composed of a supramolecular organic polymer with embedded nickel nanostructured microparticles, which shows mechanical and electrical self-healing properties at ambient conditions. We also show that our material is pressure- and flexion-sensitive, and therefore suitable for electronic skin applications. The electrical conductivity can be tuned by varying the amount of nickel particles and can reach values as high as 40 S cm-1. On rupture, the initial conductivity is repeatably restored with ~90% efficiency after 15 s healing time, and the mechanical properties are completely restored after ~10 min. The composite resistance varies inversely with applied flexion and tactile forces. These results demonstrate that natural skin's repeatable self-healing capability can be mimicked in conductive and piezoresistive materials, thus potentially expanding the scope of applications of current electronic skin systems.

  9. Proposal of abolition of the skin sensitivity test before equine rabies immune globulin application

    Directory of Open Access Journals (Sweden)

    CUPO Palmira

    2001-01-01

    Full Text Available An epizootic outbreak of rabies occurred in 1995 in Ribeirão Preto, SP, with 58 cases of animal rabies (54 dogs, 3 cats and 1 bat confirmed by the Pasteur Institute of São Paulo, and one human death. The need to provide care to a large number of people for the application of equine rabies immune globulin (ERIG prevented the execution of the skin sensitivity test (SST and often also the execution of desensitization, procedures routinely used up to that time at the Emergency Unit of the University Hospital of the Faculty of Medicine of Ribeirão Preto, University of São Paulo (EU-UHFMRP-USP, a reference hospital for the application of heterologous sera. In view of our positive experience of several years with the abolition of SST and of the use of premedication before the application of antivenom sera, we used a similar schedule for ERIG application. Of the 1489 victims of animal bites, 1054 (71% received ERIG; no patient was submitted to SST and all received intravenously anti-histamines (anti-H1 + anti-H2 and corticosteroids before the procedure. The patients were kept under observation for 60 to 180 minutes and no adverse reaction was observed. On the basis of these results, since December 1995 ERIG application has been decentralized in Ribeirão Preto and has become the responsibility of the Emergency Unit of the University Hospital and the Central Basic Health Unit, where the same routine is used. Since then, 4216 patients have received ERIG (1818 at the Basic Health Unit and 2398 at the EU-UHFMRP, with no problems. The ideal would be the routine use of human rabies immune globulin (HRIG in public health programs, but this is problematic, because of their high cost. However, while this does not occur, the use of SST is no longer justified at the time of application of ERIG, in view of the clinical evidence of low predictive value and low sensitivity of SST involving the application of heterologous sera. It is very important to point out

  10. Use of lanthanum to detect changes in the permeability barrier of rat skin after dermal exposure to organic chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Mattie, D.R.; McDougal, J.N.; Chase, M.R.; Hixson, C.J.

    1987-01-01

    Occupational dermal exposures to organic solvents are of importance due to local effects in the skin and systematic toxicity if penetration occurs through the skin. Repeated or prolonged contact with organic solvents have been shown to penetrate the skin; little information is available however, concerning effects on the barrier properties of skin after dermal exposure to solvents. This investigation examines the ultrastructural changes in rat skin after exposure of 3 organic chemicals and to correlate changes with the location of an electron-dense tracer, lanthanum, which is normally excluded by the permeability barrier in the stratum corneum. Male rats were exposed for 24 h to sterile saline, trichloroethylene (TCE), perchloroethylene (PERC), or toluene using dermal-exposure cells developed in this laboratory. Rat skin exposed to saline for 24 h appeared normal. Rat skin exposed to neat TCE, PERC or toluene for 24 h caused acute, coagulative necrosis of the epidermis and upper 1/2 to 1/3 of the dermis.

  11. Identification of Lilial as a fragrance sensitizer in a perfume by bioassay-guided chemical fractionation and structure-activity relationships.

    Science.gov (United States)

    Arnau, E G; Andersen, K E; Bruze, M; Frosch, P J; Johansen, J D; Menné, T; Rastogi, S C; White, I R; Lepoittevin, J P

    2000-12-01

    Fragrance materials are among the most common causes of allergic contact dermatitis. The aim of this study was to identify in a perfume fragrance allergens not included in the fragrance mix, by use of bioassay-guided chemical fractionation and chemical analysis/structure-activity relationships (SARs). The basis for the investigation was a 45-year-old woman allergic to her own perfume. She had a negative patch test to the fragrance mix and agreed to participate in the study. Chemical fractionation of the perfume concentrate was used for repeated patch testing and/or repeated open application test on the pre-sensitized patient. The chemical composition of the fractions giving a positive patch-test response and repeated open application test reactions was obtained by gas chromatography-mass spectrometry. From the compounds identified, those that contained a "structural alert" in their chemical structure, indicating an ability to modify skin proteins and thus behave as a skin sensitizer, were tested on the patient. The patient reacted positively to the synthetic fragrance p-t-butyl-alpha-methylhydrocinnamic aldehyde (Lilial), a widely used fragrance compound not present in the fragrance mix. The combination of bioassay-guided chemical fractionation and chemical analysis/structure-activity relationships seems to be a valuable tool for the investigation of contact allergy to fragrance materials.

  12. Polarization-Sensitive Hyperspectral Imaging in vivo: A Multimode Dermoscope for Skin Analysis

    Science.gov (United States)

    Vasefi, Fartash; MacKinnon, Nicholas; Saager, Rolf B.; Durkin, Anthony J.; Chave, Robert; Lindsley, Erik H.; Farkas, Daniel L.

    2014-05-01

    Attempts to understand the changes in the structure and physiology of human skin abnormalities by non-invasive optical imaging are aided by spectroscopic methods that quantify, at the molecular level, variations in tissue oxygenation and melanin distribution. However, current commercial and research systems to map hemoglobin and melanin do not correlate well with pathology for pigmented lesions or darker skin. We developed a multimode dermoscope that combines polarization and hyperspectral imaging with an efficient analytical model to map the distribution of specific skin bio-molecules. This corrects for the melanin-hemoglobin misestimation common to other systems, without resorting to complex and computationally intensive tissue optical models. For this system's proof of concept, human skin measurements on melanocytic nevus, vitiligo, and venous occlusion conditions were performed in volunteers. The resulting molecular distribution maps matched physiological and anatomical expectations, confirming a technologic approach that can be applied to next generation dermoscopes and having biological plausibility that is likely to appeal to dermatologists.

  13. Increased capsaicin-induced secondary hyperalgesia in patients with multiple chemical sensitivity

    DEFF Research Database (Denmark)

    Holst, Helle; Arendt-Nielsen, Lars; Mosbech, Holger;

    2011-01-01

    in experimental pain models to provoke peripheral and central sensitization. In patients with symptoms elicited by odorous chemicals capsaicin-induced secondary hyperalgesia and temporal summation were assessed as markers for abnormal central nociceptive processing together with neurogenic inflammation (flare).......the underlying cause of pathophysiological mechanisms triggering multiple chemical sensitivity (MCS) remains disputed.Recently, alterations in the central nervous system, for example,central sensitization, similar to various chronic pain disorders, have been suggested. Capsaicin is used...

  14. Keratinocyte gene expression profiles discriminate sensitizing and irritating compounds

    NARCIS (Netherlands)

    Briel, R.J. van de; Pennings, J.L.A.; Baken, K.A.; Pronk, T.E.; Boorsma, A.; Gottschalk, R.; Loveren, H. van

    2010-01-01

    Many chemicals can induce allergic contact dermatitis. Because evaluation of skin sensitizing potential by animal testing is prohibited for cosmetics, and screening of many chemicals is required within Registration, Evaluation, Authorisation and Restriction of Chemicals, urgent need exists for predi

  15. Assessment of the sensitizing potency of preservatives with chance of skin contact by the loose-fit coculture-based sensitization assay (LCSA).

    Science.gov (United States)

    Sonnenburg, Anna; Schreiner, Maximilian; Stahlmann, Ralf

    2015-12-01

    Parabens, methylisothiazolinone (MI) and its derivative methylchloroisothiazolinone (MCI), are commonly used as preservatives in personal care products. They can cause hypersensitivity reactions of the human skin. We have tested a set of nine parabens, MI alone and in combination with MCI in the loose-fit coculture-based sensitization assay (LCSA). The coculture of primary human keratinocytes and allogenic dendritic cell-related cells (DC-rc) in this assay emulates the in vivo situation of the human skin. Sensitization potency of the test substances was assessed by flow cytometric analysis of the DC-rc maturation marker CD86. Determination of the concentration required to cause a half-maximal increase in CD86-expression (EC50sens) allowed a quantitative evaluation. The cytotoxicity of test substances as indicator for irritative potency was measured by 7-AAD (7-amino-actinomycin D) staining. Parabens exhibited weak (methyl-, ethyl-, propyl- and isopropylparaben) or strong (butyl-, isobutyl-, pentyl- and benzylparaben) effects, whereas phenylparaben was found to be a moderate sensitizer. Sensitization potencies of parabens correlated with side chain length. Due to a pronounced cytotoxicity, we could not estimate an EC50sens value for MI, whereas MI/MCI was classified as sensitizer and also showed cytotoxic effects. Parabens showed no (methyl- and ethylparaben) or weak irritative potencies (propyl-, isopropyl-, butyl-, isobutyl-, phenyl- and benzylparaben), only pentylparaben was rated to be irritative. Overall, we were able to demonstrate and compare the sensitizing potencies of parabens in this in vitro test. Furthermore, we showed an irritative potency for most of the preservatives. The data further support the usefulness of the LCSA for comparison of the sensitizing potencies of xenobiotics.

  16. Probabilistic hazard assessment for skin sensitization potency by dose–response modeling using feature elimination instead of quantitative structure–activity relationships

    Science.gov (United States)

    McKim, James M.; Hartung, Thomas; Kleensang, Andre; Sá-Rocha, Vanessa

    2016-01-01

    Supervised learning methods promise to improve integrated testing strategies (ITS), but must be adjusted to handle high dimensionality and dose–response data. ITS approaches are currently fueled by the increasing mechanistic understanding of adverse outcome pathways (AOP) and the development of tests reflecting these mechanisms. Simple approaches to combine skin sensitization data sets, such as weight of evidence, fail due to problems in information redundancy and high dimension-ality. The problem is further amplified when potency information (dose/response) of hazards would be estimated. Skin sensitization currently serves as the foster child for AOP and ITS development, as legislative pressures combined with a very good mechanistic understanding of contact dermatitis have led to test development and relatively large high-quality data sets. We curated such a data set and combined a recursive variable selection algorithm to evaluate the information available through in silico, in chemico and in vitro assays. Chemical similarity alone could not cluster chemicals’ potency, and in vitro models consistently ranked high in recursive feature elimination. This allows reducing the number of tests included in an ITS. Next, we analyzed with a hidden Markov model that takes advantage of an intrinsic inter-relationship among the local lymph node assay classes, i.e. the monotonous connection between local lymph node assay and dose. The dose-informed random forest/hidden Markov model was superior to the dose-naive random forest model on all data sets. Although balanced accuracy improvement may seem small, this obscures the actual improvement in misclassifications as the dose-informed hidden Markov model strongly reduced "false-negatives" (i.e. extreme sensitizers as non-sensitizer) on all data sets. PMID:26046447

  17. Chemical dispersants used in the Gulf of Mexico oil crisis are cytotoxic and genotoxic to sperm whale skin cells.

    Science.gov (United States)

    Wise, Catherine F; Wise, James T F; Wise, Sandra S; Thompson, W Douglas; Wise, John Pierce; Wise, John Pierce

    2014-07-01

    The 2010 Deepwater Horizon oil rig explosion in the Gulf of Mexico drew attention to the need for toxicological studies of chemical dispersants. We are still learning the effects these spills had on wildlife. Little is known about the toxicity of these substances in marine mammals. The objective of this study was to determine the toxicity of the two dispersants (Corexit 9500 and 9527). Corexit 9500 and 9527 were both cytotoxic to sperm whale skin fibroblasts. Corexit 9527 was less cytotoxic than 9500. S9 mediated metabolism did not alter cytotoxicity of either dispersant. Both dispersants were genotoxic to sperm whale skin fibroblasts; S9 mediated metabolism increased Corexit 9527 genotoxicity.

  18. Quantum limit for avian magnetoreception: How sensitive can a chemical compass be?

    CERN Document Server

    Cai, Jianming; Plenio, Martin B

    2011-01-01

    The chemical compass model, based on radical pair reactions, is a fascinating idea to explain avian magnetoreception. At present, questions concerning the key ingredients responsible for the high sensitivity of a chemical compass and the possible role of quantum coherence and decoherence remain unsolved. Here, we investigate the optimized hyperfine coupling for a chemical compass in order to achieve the best magnetic field sensitivity. We demonstrate that its magnetic sensitivity limit can be further extended by simple quantum control and may benefit from additional decoherence. The present results also provide routes towards the design a biomimetic weak magnetic field sensor.

  19. A Chemical-Medical Mystery: Gold Jewelry and Black Marks on Skin

    Science.gov (United States)

    Kebbekus, Barbara B.

    2000-10-01

    Gold jewelry at times makes a black mark or smudge on skin. This may be caused by abrasive powders on the skin (e.g. zinc oxide) but the phenomenon may also be caused by other skin conditions, possibly the presence of chloride ion, acidity, or sulfur-containing amino acids. Some anecdotal evidence is published, but properly designed studies to clarify the actual causes are not available.

  20. A link between skin and airways regarding sensitivity to fragrance products?

    DEFF Research Database (Denmark)

    Elberling, J; Linneberg, A; Mosbech, Holger Fausbøll;

    2004-01-01

    Exposure to volatile fragrances is commonplace and may be related to various eye and airway symptoms. Skin exposure to fragrances is known to cause perfume contact allergy and eczema, but it is unknown whether eye or airway symptoms elicited by fragrance products are associated with contact allergy...

  1. Aluminum sulfate significantly reduces the skin test response to common allergens in sensitized patients

    Directory of Open Access Journals (Sweden)

    Grier Thomas J

    2006-02-01

    Full Text Available Abstract Background Avoidance of allergens is still recommended as the first and best way to prevent allergic illnesses and their comorbid diseases. Despite a variety of attempts there has been very limited success in the area of environmental control of allergic disease. Our objective was to identify a non-invasive, non-pharmacological method to reduce indoor allergen loads in atopic persons' homes and public environments. We employed a novel in vivo approach to examine the possibility of using aluminum sulfate to control environmental allergens. Methods Fifty skin test reactive patients were simultaneously skin tested with conventional test materials and the actions of the protein/glycoprotein modifier, aluminum sulfate. Common allergens, dog, cat, dust mite, Alternaria, and cockroach were used in the study. Results Skin test reactivity was significantly reduced by the modifier aluminum sulfate. Our studies demonstrate that the effects of histamine were not affected by the presence of aluminum sulfate. In fact, skin test reactivity was reduced independent of whether aluminum sulfate was present in the allergen test material or removed prior to testing, indicating that the allergens had in some way been inactivated. Conclusion Aluminum sulfate was found to reduce the in vivo allergic reaction cascade induced by skin testing with common allergens. The exact mechanism is not clear but appears to involve the alteration of IgE-binding epitopes on the allergen. Our results indicate that it may be possible to diminish the allergenicity of an environment by application of the active agent aluminum sulfate, thus producing environmental control without complete removal of the allergen.

  2. NOTE: Initial evaluation of acoustic reflectors for the preservation of sensitive abdominal skin areas during MRgFUS treatment

    Science.gov (United States)

    Gorny, Krzysztof R.; Chen, Shigao; Hangiandreou, Nicholas J.; Hesley, Gina K.; Woodrum, David A.; Brown, Douglas L.; Felmlee, Joel P.

    2009-04-01

    During MR-guided focused ultrasound (MRgFUS) treatments of uterine fibroids using ExAblate®2000 (InSightec, Haifa, Israel), individual tissue ablations are performed extracorporeally through the patient's abdomen using an annular array FUS transducer embedded within the MR table. Ultrasound intensities in the near field are below therapeutic levels and, under normal conditions, heating of the patient skin is minimal. However, increased absorption of ultrasound energy within sensitive skin areas or areas with differing acoustic properties, such as scars, may lead to skin burns and therefore these areas must be kept outside the near field of the FUS beam. Depending on their location and size the sensitive areas may either obstruct parts of the fibroid from being treated or prevent the entire MRgFUS treatment altogether. The purpose of this work is to evaluate acoustic reflector materials that can be applied to protect skin and the underlying sensitive areas. Reflection coefficients of cork (0.88) and foam (0.91) based materials were evaluated with a hydrophone. An ExAblate 2000 MRgFUS system was used to simulate clinical treatment with discs of reflector materials placed in a near field underneath a gel phantom. MR thermometry was used to monitor temperature elevations as well as the integrity of the focal spot. The phantom measurements showed acoustic shadow zones behind the reflectors with zone depths changing between 7 and 27 mm, for reflector disc diameters increasing from 10 to 30 mm (40 mm diameter discs completely blocked the FUS beam at the depth evaluated). The effects on thermal lesions due to the presence of the reflectors in the FUS beam were found to diminish with decreasing disc diameter and increasing sonication depth. For a 20 mm diameter disc and beyond 50 mm sonication depth, thermal lesions were minimally affected by the presence of the disc. No heating was observed on the skin side of the foam reflectors, as confirmed by measurements performed

  3. Cyclophosphamide-induced blood and tissue eosinophilia in contact sensitivity: mechanism of hapten-induced eosinophil recruitment into the skin.

    Science.gov (United States)

    Satoh, T; Chen, Q J; Sasaki, G; Yokozeki, H; Katayama, I; Nishioka, K

    1997-01-01

    The mechanism leading to selective production and accumulation of eosinophils in certain allergic skin diseases is unknown. Cyclophosphamide treatment (150 mg/kg) of BALB/c mice 48 h before sensitization with picryl chloride (PCl) resulted in striking blood and tissue eosinophilia, maximal at 13 days. Blood eosinophilia was not induced by the sensitization with oxazolone and 2,4-dinitrofluorobenzene. Challenge with 1 % PCl, but not croton oil caused preferential eosinophil accumulation into the dermis, which was associated with the enhanced expression of vascular cell adhesion molecule 1 (VCAM-1) on endothelial cells. Intravenous administration of anti-VCAM-1 monoclonal antibody abrogated eosinophil infiltration. In this murine model, we examined the role of several cytokines, including chemokines in inducing selective tissue eosinophilia in vivo. Local administration of antibodies against interleukin (IL)-1beta, IL-4, tumor necrosis factor (TNF)-alpha, and RANTES, but not against IL-5 before challenge inhibited hapten-induced eosinophil recruitment. Intradermal injection of recombinant (r)IL-1beta, rIL-4, rTNF-alpha, rRANTES, and rMIP-1alpha induced marked eosinophil accumulation. Nonetheless, intradermal rIL-5 was not a chemoattractant for eosinophils in vivo. Our findings suggest that IL-1beta, IL-4, TNF-alpha, and RANTES contribute to the selective accumulation of eosinophils in contact sensitivity reaction. Although circulating IL-5 can activate eosinophils and prolong their survival, locally secreted IL-5 is not crucial for inducing eosinophil recruitment into the skin.

  4. Non-allergic cutaneous reactions in airborne chemical sensitivity--a population based study

    DEFF Research Database (Denmark)

    Berg, Nikolaj Drimer; Linneberg, Allan; Thyssen, Jacob Pontoppidan;

    2011-01-01

    Multiple chemical sensitivity (MCS) is characterised by adverse effects due to exposure to low levels of chemical substances. The aetiology is unknown, but chemical related respiratory symptoms have been found associated with positive patch test. The purpose of this study was to investigate...... the relationship between cutaneous reactions from patch testing and self-reported severity of chemical sensitivity to common airborne chemicals. A total of 3460 individuals participating in a general health examination, Health 2006, were patch tested with allergens from the European standard series and screened...... sensitivity. Associations were controlled for the possible confounding effects of sex, age, asthma, eczema, atopic dermatitis, psychological and social factors, and smoking habits. In unadjusted analyses we found associations between allergic and non-allergic cutaneous reactions on patch testing and the two...

  5. Sensitivity of juvenile striped bass to chemicals used in aquaculture

    Energy Technology Data Exchange (ETDEWEB)

    Bills, T.D.; Marking, L.L.; Howe, G.E.

    1993-01-01

    Efforts to restore anadromous striped bass (Morone saxatilis) populations by the U.S. Fish and Wildlife Service and other agencies over the past 20 years have concentrated on hatchery culture to supplement dwindling natural reproduction. Adult fish captured for artificial spawning are stressed by handling and crowding in rearing ponds and are often exposed to therapeutants, anesthetics, disinfectants, and herbicides used in fish culture. The authors determined the toxicity of 17 fishery chemicals (chloramine-T, erythromycin, formalin, Hyamine 3500, Roccal, malachite green, sulfamerazine, benzocaine, etomidate, Finquel (MS-222), metomidate, quinaldine sulfate, chlorine, potassium permanganate, Aquazine, copper sulfate, and Rodeo) to striped bass fry (average weight = 1 g) in reconstituted water (total hardness 40 mg/L) at 12 degrees C. The 96-h LC50's (concentration calculated to produce 50% mortality in a population) ranged from 0.129 mg/L for malachite green to 340 mg/L for erythromycin.

  6. An elevated pro-inflammatory cytokine profile in multiple chemical sensitivity

    DEFF Research Database (Denmark)

    Dantoft, Thomas Meinertz; Elberling, J.; Brix, Susanne

    2014-01-01

    BackgroundMultiple chemical sensitivity (MCS) is a medically unexplained condition characterized by reports of recurrent unspecific symptoms attributed to exposure to low levels of common volatile chemicals. The etiology of MCS is poorly understood, but dysregulation of the immune system has been...

  7. Highly sensitive surface plasmon resonance chemical sensor based on Goos-Hanchen effects

    Science.gov (United States)

    Yin, Xiaobo; Hesselink, Lambertus

    2006-08-01

    The resonance enhanced Goos-Hanchen shifts at attenuated total internal reflection enables the possibility for highly sensitive surface plasmon resonance sensor. The observed giant displacements result from the singular phase retardation at the resonance where the phase is continuous but changes dramatically. The phenomenon is proposed for chemical sensing and the superior sensitivity is demonstrated.

  8. A Chemically Synthesized Capture Agent Enables the Selective, Sensitive, and Robust Electrochemical Detection of Anthrax Protective Antigen

    Science.gov (United States)

    2014-08-01

    A Chemically Synthesized Capture Agent Enables the Selective, Sensitive, and Robust Electrochemical Detection of Anthrax Protective Antigen...A Chemically Synthesized Capture Agent Enables the Selective, Sensitive, and Robust Electrochemical Detection of Anthrax Protective Antigen...AND SUBTITLE A Chemically Synthesized Capture Agent Enables the Selective, Sensitive, and Robust Electrochemical Detection of Anthrax Protective

  9. IgE Sensitization Patterns to Commonly Consumed Foods Determined by Skin Prick Test in Korean Adults

    Science.gov (United States)

    2016-01-01

    Offending food allergens can vary with regional preferences in food consumption. In this study, we analysed sensitization rates to commonly consumed foods in Korean adults suspected of having food allergy. One hundred and thirty four subjects underwent a skin prick test (SPT) with 55 food allergens, of which 13 were made by our laboratory and the rest were commercially purchased. Of the 134 patients, 73 (54.5%) were sensitized to one or more food allergens. Sensitization to chrysalis was detected most frequently, at a rate of 25.4%. Sensitization rates to other food allergens were as follows: maize grain (13.4%), shrimp (11.9%), almond (11.1%), wheat flour (8.2%), lobster (8.2%), buckwheat (8.2%), mackerel (5.2%), pollack (5.2%), halibut (4.5%), peanut (4.5%), anchovy (4.4%), squid (3.7%), saury (3.0%), common eel (3.0%), yellow corvina (3.0%), hairtail (2.2%), octopus (2.2%), and others. In addition to well-known food allergens, sensitivity to mackerel, chrysalis, pollack, and halibut, which are popular foods in Korea, was observed at high rates in Korean adults. We suggest that the SPT panel for food allergy in Korea should include these allergens. PMID:27478328

  10. Conducting polymer nanofibers for high sensitivity detection of chemical analytes.

    Science.gov (United States)

    Kumar, Abhishek; Leshchiner, Ignaty; Nagarajan, Subhalakshmi; Nagarajan, Ramaswamy; Kumar, Jayant

    2008-03-01

    Possessing large surface area materials is vital for high sensitivity detection of analyte. We report a novel, inexpensive and simple technique to make high surface area sensing interfaces using electrospinning. Conducting polymers (CP) nanotubes were made by electrospinning a solution of a catalyst (ferric tosylate) along with poly (lactic acid), which is an environment friendly biodegradable polymer. Further vapor deposition polymerization of the monomer ethylenedioxy thiophene (EDOT) on the nanofiber surface yielded poly (EDOT) covered fibers. X-ray photo electron spectroscopy (XPS) study reveals the presence of PEDOT predominantly on the surface of nanofibers. Conducting nanotubes had been received by dissolving the polymer in the fiber core. By a similar technique we had covalently incorporated fluorescent dyes on the nanofiber surface. The materials obtained show promise as efficient sensing elements. UV-Vis characterization confirms the formation of PEDOT nanotubes and incorporation of chromophores on the fiber surface. The morphological characterization was carried out using scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

  11. Evaluation of human skin tests for potential dermal irritant and contact sensitizing products: a position paper

    NARCIS (Netherlands)

    Loveren H van; Jong WH de; Garssen J; LPI

    1998-01-01

    Prediction of human cutaneous irritation and sensitization in view of hazard identification has primarily relied on the use of laboratory animals. Such studies in laboratory animals have been very instrumental in the detection of potential contact sensitizing agents. There are however many uncertain

  12. Delayed-type hypersensitivity, contact sensitivity, and phytohemagglutinin skin-test responses of heat- and cold-stressed calves.

    Science.gov (United States)

    Kelley, K W; Greenfield, R E; Evermann, J F; Parish, S M; Perryman, L E

    1982-05-01

    Three-week-old Holstein bull calves were used to investigate the effect of a 2-week chronic heat (35 C) or cold (-5 C) exposure on delayed-type hypersensitivity (DTH) reactions to purified protein derivative after sensitization with heat-killed Mycobacterium tuberculosis, contact sensitivity (CS) reactions to 1-fluoro-2,4-dinitrobenzene, and phytohemagglutinin (PHA) skin tests. Heat exposure reduced expression of DTH reactions by 42% and CS reactions by 38% at 24 hours after elicitation of the responses. The PHA-induced skin tests were not affected after 1 week of heat exposure, but this reaction was reduced by 20% after 2 weeks of heat exposure. The immune response of calves exposed to cold air temperatures was more complex. Cold exposure suppressed CS reactions by 39% at the end of both the 1st and 2nd weeks. The PHA response was reduced by 39% after 2 weeks of cold exposure. The DTH response depended on duration of cold exposure. The DTH reaction was increased by 42% after 1 week, but was reduced by 14% after 2 weeks. These data are consistent with the hypothesis that environmental stressors alter host resistance by affecting the immune system. Furthermore, these stress-induced changes in immune events depend on the type of immune response, the nature of the environmental stressor, and the length of time that calves are exposed to the stressor.

  13. [Indoor air and human health--sick house syndrome and multiple chemical sensitivity].

    Science.gov (United States)

    Ando, Masanori

    2002-01-01

    The number of complaints about the quality of indoor air has increased during the past two decades. These complaints have been frequent enough that the term "Sick House Syndrome or Sick Building Syndrome" and "Multiple Chemical Sensitivity" has been coined. Complaints are likely related to the increased use of synthetic organic materials in house, furnishing, and consumer products; and the buildings, furnishings, and consumer products; and the decreased ventilation for energy conservation in homes. Approximately thousand volatile chemicals have been identified in indoor air. The main sources of these chemicals are house materials, combustion fumes, cleaning compounds, and paints or stains. Exposure to high levels of these emissions and to others, coupled with the fact that most people spend more time indoors than outdoors, raises the possibility that the risk to human health from indoor air pollution may be potentially greater than the risk posed from outdoor pollutants. The complaints most frequently voiced with respect to Sick House Syndrome are irritations of the eye, nose, and throat; cough and hoarseness of voice; headache and mental fatigue. The syndrome of multiple chemical sensitivities is controversial subject with increasing impact on the field of indoor air quality. The controversy surrounding Multiple Chemical Sensitivity includes its definition, theories of etiology and pathogenesis, diagnostic, and life style. Multiple Chemical Sensitivity is considered the hypothesis that is a disease caused by exposure to many chemically distinct environmental substances at very low.

  14. Some sensitivity studies of chemical transport simulated in models of the soil-plant-litter system

    Energy Technology Data Exchange (ETDEWEB)

    Begovich, C.L.; Luxmoore, R.J.

    1979-09-01

    Fifteen parameters in a set of five coupled models describing carbon, water, and chemical dynamics in the soil-plant-litter system were varied in a sensitivity analysis of model response. Results are presented for chemical distribution in the components of soil, plants, and litter along with selected responses of biomass, internal chemical transport (xylem and phloem pathways), and chemical uptake. Response and sensitivity coefficients are presented for up to 102 model outputs in an appendix. Two soil properties (chemical distribution coefficient and chemical solubility) and three plant properties (leaf chemical permeability, cuticle thickness, and root chemical conductivity) had the greatest influence on chemical transport in the soil-plant-litter system under the conditions examined. Pollutant gas uptake (SO/sub 2/) increased with change in plant properties that increased plant growth. Heavy metal dynamics in litter responded to plant properties (phloem resistance, respiration characteristics) which induced changes in the chemical cycling to the litter system. Some of the SO/sub 2/ and heavy metal responses were not expected but became apparent through the modeling analysis.

  15. Some Sensitivity Studies of Chemical Transport Simulated in Models of the Soil-Plant-Litter System

    Energy Technology Data Exchange (ETDEWEB)

    Begovich, C.L.

    2002-10-28

    Fifteen parameters in a set of five coupled models describing carbon, water, and chemical dynamics in the soil-plant-litter system were varied in a sensitivity analysis of model response. Results are presented for chemical distribution in the components of soil, plants, and litter along with selected responses of biomass, internal chemical transport (xylem and phloem pathways), and chemical uptake. Response and sensitivity coefficients are presented for up to 102 model outputs in an appendix. Two soil properties (chemical distribution coefficient and chemical solubility) and three plant properties (leaf chemical permeability, cuticle thickness, and root chemical conductivity) had the greatest influence on chemical transport in the soil-plant-litter system under the conditions examined. Pollutant gas uptake (SO{sub 2}) increased with change in plant properties that increased plant growth. Heavy metal dynamics in litter responded to plant properties (phloem resistance, respiration characteristics) which induced changes in the chemical cycling to the litter system. Some of the SO{sub 2} and heavy metal responses were not expected but became apparent through the modeling analysis.

  16. Demonstration of tyrosinase in the vitiligo skin of human beings by a sensitive fluorometric method as well as by 14C(U)-L-tyrosine incorporation into melanin

    Energy Technology Data Exchange (ETDEWEB)

    Husain, I.; Vijayan, E.; Ramaiah, A.; Pasricha, J.S.; Madan, N.C.

    1982-03-01

    Tyrosinase activity (Monophenol, dihydroxyphenylalanine: oxygen oxidoreductase EC 1.14.18.1) in vitiligo and normal epidermal homogenates of skin from human beings was measured by estimating beta 3,4-dihydroxyphenylalanine (dopa) by a highly sensitive fluorometric method described in this paper. The tyrosine activity in the vitiligo skin was about 4 to 37% of corresponding normal skin. The activity of tyrosinase in normal human skin from different individuals and from different regions of the body was in the range of 4 to 140 picomoles of beta 3,4-dihydroxyphenylalanine formed per min/mg protein of epidermal homogenate. The enzyme from vitiligo and normal skin was severely inhibited by substance(s) of low molecular weight. The enzyme exhibits a lag of about 4 hr in the absence of added beta 3,4-dihydroxyphenylalanine and 1 hr in presence of 5 microM dopa. Tyrosinase from the normal and vitiligo skin was inhibited by excess concentration of tyrosine. The homogenates from vitiligo skin could synthesize melanin from C14(U)-L-Tyrosine. The rate of tyrosine incorporation into melanin by the epidermal homogenates is increased by 3,4-dihydroxyphenylalanine (dopa) disproportionate to its effect on tyrosinase activity. Based on the data presented in this paper it is concluded that melanocytes are present in the vitiligo skin. A tentative hypothesis is put forward to explain the lack of melanin synthesis by the vitiligo skin under in vivo conditions, although melanocytes are present.

  17. Sensitivity of chemical tracers to meteorological parameters in the MOZART-3 chemical transport model

    Science.gov (United States)

    Kinnison, D. E.; Brasseur, G. P.; Walters, S.; Garcia, R. R.; Marsh, D. R.; Sassi, F.; Harvey, V. L.; Randall, C. E.; Emmons, L.; Lamarque, J. F.; Hess, P.; Orlando, J. J.; Tie, X. X.; Randel, W.; Pan, L. L.; Gettelman, A.; Granier, C.; Diehl, T.; Niemeier, U.; Simmons, A. J.

    2007-10-01

    The Model for Ozone and Related Chemical Tracers, version 3 (MOZART-3), which represents the chemical and physical processes from the troposphere through the lower mesosphere, was used to evaluate the representation of long-lived tracers and ozone using three different meteorological fields. The meteorological fields are based on (1) the Whole Atmosphere Community Climate Model, version 1b (WACCM1b), (2) the European Centre for Medium-Range Weather Forecasts (ECMWF) operational analysis, and (3) a new reanalysis for year 2000 from ECMWF called EXP471. Model-derived tracers (methane, water vapor, and total inorganic nitrogen) and ozone are compared to data climatologies from satellites. Model mean age of air was also derived and compared to in situ CO2 and SF6 data. A detailed analysis of the chemical fields simulated by MOZART-3 shows that even though the general features characterizing the three dynamical sets are rather similar, slight differences in winds and temperature can produce substantial differences in the calculated distributions of chemical tracers. The MOZART-3 simulations that use meteorological fields from WACCM1b and ECMWF EXP471 represented best the distribution of long-lived tracers and mean age of air in the stratosphere. There was a significant improvement using the ECMWF EXP471 reanalysis data product over the ECMWF operational data product. The effect of the quasi-biennial oscillation circulation on long-lived tracers and ozone is examined.

  18. Analog sensitive chemical inhibition of the DEAD-box protein DDX3.

    Science.gov (United States)

    Floor, Stephen N; Barkovich, Krister J; Condon, Kendall J; Shokat, Kevan M; Doudna, Jennifer A

    2016-03-01

    Proper maintenance of RNA structure and dynamics is essential to maintain cellular health. Multiple families of RNA chaperones exist in cells to modulate RNA structure, RNA-protein complexes, and RNA granules. The largest of these families is the DEAD-box proteins, named after their catalytic Asp-Glu-Ala-Asp motif. The human DEAD-box protein DDX3 is implicated in diverse biological processes including translation initiation and is mutated in numerous cancers. Like many DEAD-box proteins, DDX3 is essential to cellular health and exhibits dosage sensitivity, such that both decreases and increases in protein levels can be lethal. Therefore, chemical inhibition would be an ideal tool to probe the function of DDX3. However, most DEAD-box protein active sites are extremely similar, complicating the design of specific inhibitors. Here, we show that a chemical genetic approach best characterized in protein kinases, known as analog-sensitive chemical inhibition, is viable for DDX3 and possibly other DEAD-box proteins. We present an expanded active-site mutant that is tolerated in vitro and in vivo, and is sensitive to chemical inhibition by a novel bulky inhibitor. Our results highlight a course towards analog sensitive chemical inhibition of DDX3 and potentially the entire DEAD-box protein family.

  19. Sensitivity of chemical reaction networks: a structural approach. 1. Examples and the carbon metabolic network.

    Science.gov (United States)

    Mochizuki, Atsushi; Fiedler, Bernold

    2015-02-21

    In biological cells, chemical reaction pathways lead to complex network systems like metabolic networks. One experimental approach to the dynamics of such systems examines their "sensitivity": each enzyme mediating a reaction in the system is increased/decreased or knocked out separately, and the responses in the concentrations of chemicals or their fluxes are observed. In this study, we present a mathematical method, named structural sensitivity analysis, to determine the sensitivity of reaction systems from information on the network alone. We investigate how the sensitivity responses of chemicals in a reaction network depend on the structure of the network, and on the position of the perturbed reaction in the network. We establish and prove some general rules which relate the sensitivity response to the structure of the underlying network. We describe a hierarchical pattern in the flux response which is governed by branchings in the network. We apply our method to several hypothetical and real life chemical reaction networks, including the metabolic network of the Escherichia coli TCA cycle.

  20. Quantification of Eosinophilic Granule Protein Deposition in Biopsies of Inflammatory Skin Diseases by Automated Image Analysis of Highly Sensitive Immunostaining

    Directory of Open Access Journals (Sweden)

    Peter Kiehl

    1999-01-01

    Full Text Available Eosinophilic granulocytes are major effector cells in inflammation. Extracellular deposition of toxic eosinophilic granule proteins (EGPs, but not the presence of intact eosinophils, is crucial for their functional effect in situ. As even recent morphometric approaches to quantify the involvement of eosinophils in inflammation have been only based on cell counting, we developed a new method for the cell‐independent quantification of EGPs by image analysis of immunostaining. Highly sensitive, automated immunohistochemistry was done on paraffin sections of inflammatory skin diseases with 4 different primary antibodies against EGPs. Image analysis of immunostaining was performed by colour translation, linear combination and automated thresholding. Using strictly standardized protocols, the assay was proven to be specific and accurate concerning segmentation in 8916 fields of 520 sections, well reproducible in repeated measurements and reliable over 16 weeks observation time. The method may be valuable for the cell‐independent segmentation of immunostaining in other applications as well.

  1. Association of 25-hydroxyvitamin D3)levels in adult New Zealanders with ethnicity, skin color and self-reported skin sensitivity to sun exposure.

    Science.gov (United States)

    Nessvi, Sofia; Johansson, Lisa; Jopson, Jan; Stewart, Alistair; Reeder, Anthony; McKenzie, Richard; Scragg, Robert K

    2011-01-01

    The study aim was to determine the contribution of ethnicity, objectively measured skin color and skin reaction-to-sun exposure to variations in 25-hydroxyvitamin D(3) [25(OH)D(3) ]. A multiethnic sample (European, Maori, Pacific and Asian) of 503 adult volunteers aged 18-85 years, recruited from Auckland and Dunedin in New Zealand, answered a questionnaire on sun exposure and self-defined ethnicity. Skin color was measured using a spectrophotometer and the Individual Typology Angle (ITA) calculated. A blood sample was collected 4 weeks later to measure 25(OH)D(3). 25(OH)D(3) was associated with ethnicity, but not self-reported skin reaction-to-sun exposure. Amongst the ethnic groups, Asians had the lowest mean 25(OH)D level (37.0 nmol L(-1)) and Europeans with lighter colored skin had the highest (57.9 nmol L(-1)). An association also was seen between 25(OH)D(3) and skin color, with an increase of 2-3 nmol L(-1) per 10° increase in ITA value, indicating higher 25(OH)D(3) with lighter skin color; but much of this association disappeared after adjusting for ethnicity. In contrast, ethnicity remained associated with 25(OH)D(3) after adjusting for ITA skin color and skin reaction-to-sun exposure. These results indicate that self-defined ethnicity was a major determinant of variations in serum 25(OH)D(3), while objective measures of skin color explained relatively little additional variation.

  2. Skin penetration and metabolism of topically applied chemicals in six mammalian species, including man: an in vitro study with benzo(a)pyrene and testosterone

    Energy Technology Data Exchange (ETDEWEB)

    Kao, J.; Patterson, F.K.; Hall, J.

    1985-12-01

    Because viable skin possesses enzyme activities, including those involved in the metabolism of xenobiotics, the extent to which cutaneous metabolism may influence the percutaneous fate of topically applied chemicals in the skin was examined in mammalian skin maintained as short-term organ cultures. Skin samples from mouse, rat, rabbit, guinea pig, marmoset, and man were examined. The results from studies with benzo(a)pyrene (BP) and testosterone showed that, in all species, metabolic viability was a major factor involved in the in vitro skin permeation of surface-applied chemicals. Permeation was accompanied by extensive cutaneous first pass metabolism; both parent compounds and a full spectrum of metabolites were found in the receptor fluid from viable skin preparations. However, in previously frozen nonviable skin preparations, essentially only unchanged parent compounds were detected in the receptor fluid. Permeation of BP and testosterone was highest in mouse skin, and significant species variations in the metabolite profiles were observed. Studies with mouse skin also demonstrated that induction of cutaneous drug-metabolizing enzymes can result in a two- to threefold increase in the in vitro permeation of topical BP, and a significant reduction in permeation was observed when KCN was added to the perfusion medium. These results indicate that diffusional and metabolic processes are intimately involved in the percutaneous fate of surface-applied chemicals. The relative importance of these processes is dependent upon the physicochemical properties of the compounds and the metabolic capabilities of the skin toward the compounds in question. Furthermore, these findings suggest that meaningful in vitro studies on skin absorption should consider both diffusion and cutaneous biotransformation of the applied compound.

  3. Tactile surface classification for limbed robots using a pressure sensitive robot skin.

    Science.gov (United States)

    Shill, Jacob J; Collins, Emmanuel G; Coyle, Eric; Clark, Jonathan

    2015-02-02

    This paper describes an approach to terrain identification based on pressure images generated through direct surface contact using a robot skin constructed around a high-resolution pressure sensing array. Terrain signatures for classification are formulated from the magnitude frequency responses of the pressure images. The initial experimental results for statically obtained images show that the approach yields classification accuracies [Formula: see text]. The methodology is extended to accommodate the dynamic pressure images anticipated when a robot is walking or running. Experiments with a one-legged hopping robot yield similar identification accuracies [Formula: see text]. In addition, the accuracies are independent with respect to changing robot dynamics (i.e., when using different leg gaits). The paper further shows that the high-resolution capabilities of the sensor enables similarly textured surfaces to be distinguished. A correcting filter is developed to accommodate for failures or faults that inevitably occur within the sensing array with continued use. Experimental results show using the correcting filter can extend the effective operational lifespan of a high-resolution sensing array over 6x in the presence of sensor damage. The results presented suggest this methodology can be extended to autonomous field robots, providing a robot with crucial information about the environment that can be used to aid stable and efficient mobility over rough and varying terrains.

  4. Reduction of Salmonella on chicken meat and chicken skin by combined or sequential application of lytic bacteriophage with chemical antimicrobials.

    Science.gov (United States)

    Sukumaran, Anuraj T; Nannapaneni, Rama; Kiess, Aaron; Sharma, Chander Shekhar

    2015-08-17

    The effectiveness of recently approved Salmonella lytic bacteriophage preparation (SalmoFresh™) in reducing Salmonella in vitro and on chicken breast fillets was examined in combination with lauric arginate (LAE) or cetylpyridinium chloride (CPC). In another experiment, a sequential spray application of this bacteriophage (phage) solution on Salmonella inoculated chicken skin after a 20s dip in chemical antimicrobials (LAE, CPC, peracetic acid, or chlorine) was also examined in reducing Salmonella counts on chicken skin. The application of phage in combination with CPC or LAE reduced S. Typhimurium, S. Heidelberg, and S. Enteritidis up to 5 log units in vitro at 4 °C. On chicken breast fillets, phage in combination with CPC or LAE resulted in significant (pSalmonella ranging from 0.5 to 1.3 log CFU/g as compared to control up to 7 days of refrigerated storage. When phage was applied sequentially with chemical antimicrobials, all the treatments resulted in significant reductions of Salmonella. The application of chlorine (30 ppm) and PAA (400 ppm) followed by phage spray (10(9)PFU/ml) resulted in highest Salmonella reductions of 1.6-1.7 and 2.2-2.5l og CFU/cm(2), respectively. In conclusion, the surface applications of phage in combination with LAE or CPC significantly reduced Salmonella counts on chicken breast fillets. However, higher reductions in Salmonella counts were achieved on chicken skin by the sequential application of chemical antimicrobials followed by phage spray. The sequential application of chlorine, PAA, and phage can provide additional hurdles to reduce Salmonella on fresh poultry carcasses or cut up parts.

  5. Detection of potentially skin sensitizing hydroperoxides of linalool in fragranced products.

    Science.gov (United States)

    Kern, Susanne; Dkhil, Hafida; Hendarsa, Prisca; Ellis, Graham; Natsch, Andreas

    2014-10-01

    On prolonged exposure to air, linalool can form sensitizing hydroperoxides. Positive hydroperoxide patch tests in dermatitis patients have frequently been reported, but their relevance has not been established. Owing to a lack of analytical methods and data, it is unclear from which sources the public might be exposed to sufficient quantities of hydroperoxides for induction of sensitization to occur. To address this knowledge gap, we developed analytical methods and performed stability studies for fine fragrances and deodorants/antiperspirants. In parallel, products recalled from consumers were analysed to investigate exposure to products used in everyday life. Liquid chromatography-mass spectrometry with high mass resolution was found to be optimal for the selective and sensitive detection of the organic hydroperoxide in the complex product matrix. Linalool hydroperoxide was detected in natural linalool, but the amount was not elevated by storage in a perfume formulation exposed to air. No indication of hydroperoxide formation in fine fragrances was found in stability studies. Aged fine fragrances recalled from consumers contained a geometric mean linalool concentration of 1,888 μg/g and, corrected for matrix effects, linalool hydroperoxide at a concentration of around 14 μg/g. In antiperspirants, we detected no oxidation products. In conclusion, very low levels of linalool hydroperoxide in fragranced products may originate from raw materials, but we found no evidence for oxidation during storage of products. The levels detected are orders of magnitude below the levels inducing sensitization in experimental animals, and these results therefore do not substantiate a causal link between potential hydroperoxide formation in cosmetics and positive results of patch tests.

  6. Protective effects of black rice bran against chemically-induced inflammation of mouse skin

    Science.gov (United States)

    We investigated the inhibitory effects of black rice (cv. LK1-3-6-12-1-1) bran against 12-O-tetradecanolylphorbol-13-acetate (TPA)-induced skin edema and 2,4-dinitroflurobenzene (DNFB)-induced allergic contact dermatitis (ACD) in inflammatory mouse models. We also determined the effects of the bran...

  7. Risk of sensitization in healthy adults following repeated administration of rdESAT-6 skin test reagent by the Mantoux injection technique

    DEFF Research Database (Denmark)

    Lillebaek, Troels; Bergstedt, Winnie; Tingskov, Pernille N;

    2009-01-01

    1 open clinical trial was to assess the sensitization risk and safety of repeated administration of rdESAT-6 reagent in 31 healthy adult volunteers. Three groups of volunteers received two fixed doses of 0.1 microg rdESAT-6 28, 56 or 112 days apart, respectively. After the second injection......Limited specificity of the tuberculin skin test incited the development of the intradermal Mycobacterium tuberculosis-specific rdESAT-6 skin test. Animal studies have shown, however, that there is a possible risk of sensitization when repeated injections of rdESAT-6 are given. The aim of this phase...

  8. A Fast and Robust UHPLC-MRM-MS Method to Characterize and Quantify Grape Skin Tannins after Chemical Depolymerization

    Directory of Open Access Journals (Sweden)

    Lucie Pinasseau

    2016-10-01

    Full Text Available A rapid, sensitive, and selective analysis method using ultra high performance liquid chromatography coupled with triple-quadrupole mass spectrometry (UHPLC-QqQ-MS has been developed for the characterization and quantification of grape skin flavan-3-ols after acid-catalysed depolymerization in the presence of phloroglucinol (phloroglucinolysis. The compound detection being based on specific MS transitions in Multiple Reaction Monitoring (MRM mode, this fast gradient robust method allows analysis of constitutive units of grape skin proanthocyanidins, including some present in trace amounts, in a single injection, with a throughput of 6 samples per hour. This method was applied to a set of 214 grape skin samples from 107 different red and white grape cultivars grown under two conditions in the vineyard, irrigated or non-irrigated. The results of triplicate analyses confirmed the robustness of the method, which was thus proven to be suitable for high-throughput and large-scale metabolomics studies. Moreover, these preliminary results suggest that analysis of tannin composition is relevant to investigate the genetic bases of grape response to drought.

  9. Inhibition of Neoplastic Transformation and Chemically-Induced Skin Hyperplasia in Mice by Traditional Chinese Medicinal Formula Si-Wu-Tang

    Science.gov (United States)

    Liu, Mandy M.; Huang, Kevin M.; Yeung, Steven; Chang, Andy; Zhang, Suhui; Mei, Nan; Parsa, Cyrus; Orlando, Robert; Huang, Ying

    2017-01-01

    Exploring traditional medicines may lead to the development of low-cost and non-toxic cancer preventive agents. Si-Wu-Tang (SWT), comprising the combination of four herbs, Rehmanniae, Angelica, Chuanxiong, and Paeoniae, is one of the most popular traditional Chinese medicines for women’s diseases. In our previous studies, the antioxidant Nrf2 pathways were strongly induced by SWT in vitro and in vivo. Since Nrf2 activation has been associated with anticarcinogenic effects, the purpose of this study is to evaluate SWT’s activity of cancer prevention. In the Ames test, SWT demonstrated an antimutagenic activity against mutagenicity induced by the chemical carcinogen 7,12-dimethylbenz(a)anthracene (DMBA). In JB6 P+ cells, a non-cancerous murine epidermal model for studying tumor promotion, SWT inhibited epidermal growth factor (EGF)-induced neoplastic transformation. The luciferase reporter gene assays demonstrated that SWT suppressed EGF-induced AP-1 and TNF-α-induced NF-κB activation, which are essential factors involved in skin carcinogenesis. In a DMBA-induced skin hyperplasia assay in ‘Sensitivity to Carcinogenesis’ (SENCAR) mice, both topical and oral SWT inhibited DMBA-induced epidermal hyperplasia, expression of the proliferation marker Proliferating cell nuclear antigen (PCNA), and H-ras mutations. These findings demonstrate, for the first time, that SWT prevents tumor promoter and chemical-induced carcinogenesis in vitro and in vivo, partly by inhibiting DNA damage and blocking the activation of AP-1 and NF-κB. PMID:28335476

  10. Evolution of metastasis revealed by mutational landscapes of chemically induced skin cancers | Office of Cancer Genomics

    Science.gov (United States)

    Human tumors show a high level of genetic heterogeneity, but the processes that influence the timing and route of metastatic dissemination of the subclones are unknown. Here we have used whole-exome sequencing of 103 matched benign, malignant and metastatic skin tumors from genetically heterogeneous mice to demonstrate that most metastases disseminate synchronously from the primary tumor, supporting parallel rather than linear evolution as the predominant model of metastasis.

  11. Chemopreventive potential of Annona muricata L leaves on chemically-induced skin papillomagenesis in mice.

    Science.gov (United States)

    Hamizah, Sulaiman; Roslida, A H; Fezah, O; Tan, K L; Tor, Y S; Tan, C I

    2012-01-01

    Annona muricata L (Annonaceae), commonly known as soursop has a long, rich history in herbal medicine with a lengthy recorded indigenous use. It had also been found to be a promising new anti-tumor agent in numerous in vitro studies. The present investigation concerns chemopreventive effects in a two-stage model of skin papillomagenesis. Chemopreventive effects of an ethanolic extract of A. muricata leaves (AMLE) was evaluated in 6-7 week old ICR mice given a single topical application of 7,12-dimethylbenza(α)anthracene (DMBA 100 μg/100 μl acetone) and promotion by repeated application of croton oil (1% in acetone/ twice a week) for 10 weeks. Morphological tumor incidence, burden and volume were measured, with histological evaluation of skin tissue. Topical application of AMLE at 30, 100 and 300 mg/kg significantly reduced DMBA/croton oil induced mice skin papillomagenesis in (i) peri-initiation protocol (AMLE from 7 days prior to 7 days after DMBA), (ii) promotion protocol (AMLE 30 minutes after croton oil), or (iii) both peri-initiation and promotion protocol (AMLE 7 days prior to 7 day after DMBA and AMLE 30 minutes after croton oil throughout the experimental period), in a dose dependent manner (pmuricata leaves extract was able to suppress tumor initiation as well as tumor promotion even at lower dosage.

  12. [Sensitivity of Pseudomonas chlororaphis to antibiotics and chemical tools of plant protection].

    Science.gov (United States)

    Shepelevich, V V; Kiprianova, E A; Iaroshenko, L V; Avdeeva, L V

    2012-01-01

    Examination of sensitivity of 10 Pseudomonas chlororaphis strains belonging to different subspecies to 54 antibiotics has shown that all studied representatives of Pchlororaphis subsp. chlororaphis, P. chlororaphis subsp. aureofaciens and Pchlororaphis subsp. aurantiaca were sensitive to aminoglycoside antibiotics and fluoroquinolones derivatives. Only part of studied strains has shown sensitivity to some beta-lactam antibiotics, imipeneme and meropeneme. In contrast to representatives of two other subspecies both strains of P. chlororaphis subsp. chlororaphis proved to be sensitive to chlortetracycline and cefepime that allows to consider this difference as the characteristic useful for differentiation. All studied P. chlororaphis strains were resistant to chemical fungicides (Scor and Svitch) and the insect growth regulators (Match, Lufox, Engio, Actellik). Resistance of bacteria to these herbicides gives evidence that their combined use is possible.

  13. Low sensitivity of type VII collagen enzyme-linked immunosorbent assay in epidermolysis bullosa acquisita : serration pattern analysis on skin biopsy is required for diagnosis

    NARCIS (Netherlands)

    Terra, J. B.; Jonkman, M. F.; Diercks, G. F. H.; Pas, H. H.

    2013-01-01

    BackgroundThe type VII collagen (coll VII) enzyme-linked immunosorbent assay (ELISA) has been reported to have high sensitivity (>93%) and specificity (>96%) for diagnosing epidermolysis bullosa acquisita (EBA) in patients who are seropositive on indirect immunofluorescence on salt-split skin (SSS).

  14. Comparative sensitivity of human and rat neural cultures to chemical-induced inhibition of neurite outgrowth

    Energy Technology Data Exchange (ETDEWEB)

    Harrill, Joshua A.; Freudenrich, Theresa M.; Robinette, Brian L.; Mundy, William R., E-mail: mundy.william@epa.gov

    2011-11-15

    There is a need for rapid, efficient and cost-effective alternatives to traditional in vivo developmental neurotoxicity testing. In vitro cell culture models can recapitulate many of the key cellular processes of nervous system development, including neurite outgrowth, and may be used as screening tools to identify potential developmental neurotoxicants. The present study compared primary rat cortical cultures and human embryonic stem cell-derived neural cultures in terms of: 1) reproducibility of high content image analysis based neurite outgrowth measurements, 2) dynamic range of neurite outgrowth measurements and 3) sensitivity to chemicals which have been shown to inhibit neurite outgrowth. There was a large increase in neurite outgrowth between 2 and 24 h in both rat and human cultures. Image analysis data collected across multiple cultures demonstrated that neurite outgrowth measurements in rat cortical cultures were more reproducible and had higher dynamic range as compared to human neural cultures. Human neural cultures were more sensitive than rat cortical cultures to chemicals previously shown to inhibit neurite outgrowth. Parallel analysis of morphological (neurite count, neurite length) and cytotoxicity (neurons per field) measurements were used to detect selective effects on neurite outgrowth. All chemicals which inhibited neurite outgrowth in rat cortical cultures did so at concentrations which did not concurrently affect the number of neurons per field, indicating selective effects on neurite outgrowth. In contrast, more than half the chemicals which inhibited neurite outgrowth in human neural cultures did so at concentrations which concurrently decreased the number of neurons per field, indicating that effects on neurite outgrowth were secondary to cytotoxicity. Overall, these data demonstrate that the culture models performed differently in terms of reproducibility, dynamic range and sensitivity to neurite outgrowth inhibitors. While human neural

  15. Development of High Temperature/High Sensitivity Novel Chemical Resistive Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chonglin; Nash, Patrick; Ma, Chunrui; Enriquez, Erik; Wang, Haibing; Xu, Xing; Bao, Shangyong; Collins, Gregory

    2013-08-13

    The research has been focused to design, fabricate, and develop high temperature/high sensitivity novel multifunctional chemical sensors for the selective detection of fossil energy gases used in power and fuel systems. By systematically studying the physical properties of the LnBaCo{sub 2}O{sub 5+d} (LBCO) [Ln=Pr or La] thin-films, a new concept chemical sensor based high temperature chemical resistant change has been developed for the application for the next generation highly efficient and near zero emission power generation technologies. We also discovered that the superfast chemical dynamic behavior and an ultrafast surface exchange kinetics in the highly epitaxial LBCO thin films. Furthermore, our research indicates that hydrogen can superfast diffuse in the ordered oxygen vacancy structures in the highly epitaxial LBCO thin films, which suggest that the LBCO thin film not only can be an excellent candidate for the fabrication of high temperature ultra sensitive chemical sensors and control systems for power and fuel monitoring systems, but also can be an excellent candidate for the low temperature solid oxide fuel cell anode and cathode materials.

  16. Sensitivity of two garden pea genotypes to physical and chemical mutagens

    OpenAIRE

    Slavka Kalapchieva; Nasya Tomlekova

    2016-01-01

    A study on the sensitivity of two breeding lines of garden pea to mutagenic agents was carried out in the Maritsa Vegetable Crops Research Institute, Plovdiv. The purpose was to evaluate the sensitivity of the Pisum sativum L. genotypes to physical and chemical mutagens. In the experiment, the pea seeds were irradiated single or combined with 60Co gamma rays (40, 80, 100, 200 and 400 Gy) and Ethyl methanesulfonate (EMS) at concentrations of 0.1 and 0.2 %. Visible morphological changes of the ...

  17. Apoptosis is an early event during phthalocyanine photodynamic therapy-induced ablation of chemically induced squamous papillomas in mouse skin.

    Science.gov (United States)

    Agarwal, R; Korman, N J; Mohan, R R; Feyes, D K; Jawed, S; Zaim, M T; Mukhtar, H

    1996-04-01

    Photodynamic therapy (PDT) is a promising new modality to treat malignant neoplasms including superficial skin cancers. In our search for an ideal photosensitizer for PDT, Pc 4, a silicon phthalocyanine, has shown promising results both in in vitro assays and in implanted tumors. In this study we assessed the efficacy of Pc 4 PDT in the ablation of murine skin tumors; and the evidence for apoptosis during tumor ablation was also obtained. The Pc 4 was administered through tail vein injection to SENCAR mice bearing chemically induced squamous papillomas, and 24 h later the lesions were illuminated with an argon ion-pumped dye laser tuned at 675 nm for a total light dose of 135 J/cm2. Within 72-96 h, almost complete tumor shrinkage occurred; no tumor regrowth was observed up to 90 days post-PDT. As evident by nucleosome-size DNA fragmentation, appearance of apoptotic bodies in hematoxylin and eosin staining and direct immunoperoxidase detection of digoxigenin-labeled genomic DNA in sections, apoptosis was clearly evident 6 h post-PDT at which time tumor shrinkage was less than 30%. The apoptotic bodies, as evident by the condensation of chromatin material around the periphery of the nucleus and increased vacuolization of the cytoplasm, were also observed in electron microscopic studies of the tumor tissues following Pc 4 PDT. The extent of apoptosis was greater at 15 h than at 6 and 10 h post-PDT. Taken together, our results clearly show that Pc 4 may be an effective photosensitizer for PDT of nonmelanoma skin cancer, and that apoptosis is an early event during this process.

  18. MC1R gene polymorphism affects skin color and phenotypic features related to sun sensitivity in a population of French adult women.

    Science.gov (United States)

    Latreille, Julie; Ezzedine, Khaled; Elfakir, Anissa; Ambroisine, Laurence; Gardinier, Sophie; Galan, Pilar; Hercberg, Serge; Gruber, Florian; Rees, Jonathan; Tschachler, Erwin; Guinot, Christiane

    2009-01-01

    The melanocortin-1 receptor (MC1R) gene is known to play a major role in skin and hair pigmentation and to be highly polymorphic in Caucasians. This study was performed to investigate the relationships between MC1R gene polymorphisms and skin color in a large sample of French middle-aged Caucasian women. The codons 60 to 265 and the codon 294 of the MC1R gene were sequenced in 488 women. The skin color was measured on the inner side of the forearm using a spectrophotometric instrument. Fifteen variants were identified: Arg151Cys, Arg160Trp, Arg142His, Asp294His, Ile155Thr, Asp84Glu, Val60Leu, Val92Met, Arg163Gln, Ser83Pro, Thr95Met, Pro256Ser, Val265Ile, Ala166Ala and Gln233Gln. Women carrying Arg151Cys, Asp294His, Arg160Trp and Asp84Glu variants had a significantly higher reflectance in the red region, which indicates a lower level of functional melanin. This association was the most pronounced for women carrying Asp84Glu. In contrast, no significant difference was observed for other variants. Moreover, associations between MC1R polymorphisms and the risks of experiencing sunburn and of having freckles were found independently of skin color. Our findings support the hypothesis that MC1R polymorphisms do not necessarily alter the skin color but should sensitize the skin to UV-induced DNA damage.

  19. Keratinocyte p38δ loss inhibits Ras-induced tumor formation, while systemic p38δ loss enhances skin inflammation in the early phase of chemical carcinogenesis in mouse skin.

    Science.gov (United States)

    Kiss, Alexi; Koppel, Aaron C; Anders, Joanna; Cataisson, Christophe; Yuspa, Stuart H; Blumenberg, Miroslav; Efimova, Tatiana

    2016-05-01

    p38δ expression and/or activity are increased in human cutaneous malignancies, including invasive squamous cell carcinoma (SCC) and head and neck SCC, but the role of p38δ in cutaneous carcinogenesis has not been well-defined. We have reported that mice with germline loss of p38δ exhibited a reduced susceptibility to skin tumor development compared with wild-type mice in the two-stage 7,12-dimethylbenz(a)anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA) chemical skin carcinogenesis model. Here, we report that p38δ gene ablation inhibited the growth of tumors generated from v-ras(Ha) -transformed keratinocytes in skin orthografts to nude mice, indicating that keratinocyte-intrinsic p38δ is required for Ras-induced tumorigenesis. Gene expression profiling of v-ras(Ha) -transformed p38δ-null keratinocytes revealed transcriptional changes associated with cellular responses linked to tumor suppression, such as reduced proliferation and increased differentiation, cell adhesion, and cell communications. Notably, a short-term DMBA/TPA challenge, modeling the initial stages of chemical skin carcinogenesis treatment, elicited an enhanced inflammation in p38δ-null skin compared with skin of wild-type mice, as assessed by measuring the expression of pro-inflammatory cytokines, including IL-1β, IL-6, IL-17, and TNFα. Additionally, p38δ-null skin and p38δ-null keratinocytes exhibited increased p38α activation and signaling in response to acute inflammatory challenges, suggesting a role for p38α in stimulating the elevated inflammatory response in p38δ-null skin during the initial phases of the DMBA/TPA treatment compared with similarly treated p38δ(+/+) skin. Altogether, our results indicate that p38δ signaling regulates skin carcinogenesis not only by keratinocyte cell-autonomous mechanisms, but also by influencing the interaction between between the epithelial compartment of the developing skin tumor and its stromal microenvironment.

  20. In vitro percutaneous absorption of tenoxicam from pressure-sensitive adhesive matrices across the hairless mouse skin.

    Science.gov (United States)

    Gwak, H S; Chun, I K

    2001-12-01

    To investigate the feasibility of developing a new tenoxicam plaster, the effects of vehicles and penetration enhancers on the in vitro permeation of tenoxicam from a pressure-sensitive adhesive (PSA) matrices across the dorsal hairless mouse skin were studied. Vehicles employed in this study were propylene glycol (PG)-oleyl alcohol (OAI), PG-oleic acid (OA), and diethylene glycol monoethyl ether (DGME)-propylene glycol monolaurate (PGML) cosolvents with/without fatty acids. In this study, amines such as triethanolamine (TEA) and tromethamine (TM) were additionally used as a solubilizer. Among PSAs used, Duro-Tak 87-2510 showed much higher release rate than either Duro-Tak 87-2100 or Duro-Tak 87-2196. The relatively high flux rate was obtained with the formulation of DGME-PGML (40:60, v/v) with 3% OA and 5% TM, and the flux increased as a function of the dose; the initial flux up to 12 h was 4.98 +/- 1.38 microg/cm2/h at the tenoxicam dose of 50 mg/70 cm2. This flux was much higher than that of a commercial piroxicam patch (Trast) (1.24 +/- 0.73 microg/ cm2/hr) with almost only one-third that of the commercial patch. Therefore, these observations indicated that these composition of tenoxicam plaster may be practically applicable.

  1. Rapid and sensitive reporter gene assays for detection of antiandrogenic and estrogenic effects of environmental chemicals

    DEFF Research Database (Denmark)

    Vinggaard, Anne; Jørgensen, E.C.B.; Larsen, John Christian

    1999-01-01

    cotransfected with the human androgen receptor expression vector and the mouse mammary tumour virus (MMTV)(2)-luciferase vector using the new nonliposomal transfection reagent FuGene, Stimulation of the cells for 24 h with the synthetic androgen receptor agonist, R1881 (10 nM), resulted in a 30- to 60-fold...... antiandrogenic chemicals present in our environment. Thus, there is a great need for an effective in vitro screening method for (anti)androgenic chemicals. We have developed a rapid, sensitive, and reproducible reporter gene assay for detection of antiandrogenic chemicals. Chinese Hamster Ovary cells were......-on laboratory time. This assay is a powerful tool for the efficient and accurate determination and quantification of the effects of antiandrogens on reporter gene transcription, To extend the application of FuGene, the reagent was shown to be superior compared to Lipofectin for transfecting MCF7 human breast...

  2. Rapid and Sensitive Reporter Gene Assays for Detection of Antiandrogenic and Estrogenic Effects of Environmental Chemicals

    DEFF Research Database (Denmark)

    Vinggaard, Anne Marie; Bonefeld-Jørgensen, Eva Cecilie; Larsen, John Christian

    1999-01-01

    cotransfected with the human androgen receptor expression vector and the mouse mammary tumour virus (MMTV)2-luciferase vector using the new nonliposomal transfection reagent FuGene. Stimulation of the cells for 24 h with the synthetic androgen receptor agonist, R1881 (10 nM), resulted in a 30- to 60-fold...... antiandrogenic chemicals present in our environment. Thus, there is a great need for an effectivein vitroscreening method for (anti)androgenic chemicals. We have developed a rapid, sensitive, and reproducible reporter gene assay for detection of antiandrogenic chemicals. Chinese Hamster Ovary cells were......-on laboratory time. This assay is a powerful tool for the efficient and accurate determination and quantification of the effects of antiandrogens on reporter gene transcription. To extend the application of FuGene, the reagent was shown to be superior compared to Lipofectin for transfecting MCF7 human breast...

  3. An assay to determine the sensitive window of embryos to chemical exposure using Xenopus tropicalis.

    Science.gov (United States)

    Hu, Lingling; Wu, Lijiao; Xue, Yingang; Zhu, Jingmin; Shi, Huahong

    2016-05-01

    The frog embryo teratogenesis assay-Xenopus (FETAX) is an established method to evaluate the developmental toxicity of chemicals. In FETAX, a 48 h continuous exposure is usually conducted when the X. tropicalis embryo is used as the test model. In the present study, we exposed X. tropicalis embryos to nine known teratogens for four separate 12-h periods. The embryos showed great variations in response to nine tested compounds during different exposure periods. Based on the value of the score of malformations, the most sensitive 12 h exposure periods of embryos were significantly distinguished for all the compounds with the exception of NiCl2 . The embryos were the most sensitive to retinols (e.g. all-trans-retinoic acid and 9-cis-retinoic acid) during 0-12 h and to metal compounds (e.g. triphenlytin and CdCl2) during a 24 to 36 h exposure period. In the further 3 h exposure experiment, the most sensitive period could only be determined for one of three tested compounds. Based on the present results, we proposed an assay to determine a 12 h sensitive window of embryos to chemical exposure using Xenopus tropicalis.

  4. Skin Barrier Function and Allergens

    DEFF Research Database (Denmark)

    Engebretsen, Kristiane Aasen; Thyssen, Jacob Pontoppidan

    2016-01-01

    The skin is an important barrier protecting us from mechanical insults, microorganisms, chemicals and allergens, but, importantly, also reducing water loss. A common hallmark for many dermatoses is a compromised skin barrier function, and one could suspect an elevated risk of contact sensitization...... and skin barrier status. Psoriasis has traditionally been regarded a Th1-dominated disease, but the discovery of Th17 cells and IL-17 provides new and interesting information regarding the pathogenesis of the disease. Research suggests an inverse relationship between psoriasis and CA, possibly due......) and Th2 (AD) have been proposed as an explanation. Finally, there is convincing evidence that exposure to irritants increases the risk of CS, and patients with ICD are, therefore, at great risk of developing CA. Skin irritation leads to the release of IL-1 and TNF-α, which affects the function of antigen...

  5. Chemical characterization of Citrus limon var. pompia and incorporation in phospholipid vesicles for skin delivery.

    Science.gov (United States)

    Manconi, Maria; Manca, Maria Letizia; Marongiu, Francesca; Caddeo, Carla; Castangia, Ines; Petretto, Giacomo Luigi; Pintore, Giorgio; Sarais, Giorgia; D'hallewin, Guy; Zaru, Marco; Bacchetta, Gianluigi; Fadda, Anna Maria

    2016-06-15

    The components of pompia, a hybrid Citrus species cultivated only in Sardinia (Italy), were extracted using an environmentally-friendly method and food-grade solvents. Taking into account that only few data are available on pompia composition, the phytochemical fingerprint of its rind extract was obtained by accurate component separation and identification, combining HPLC and mass spectrometry. Different flavones such as naringin (23.77μg/mg), neoeriocitrin (46.53μg/mg) and neohesperidin (44.57μg/mg) were identified. Additionally, the antioxidant activity and phenolic content were confirmed by DPPH and Folin-Ciocalteu assays. The whole extract was incorporated in innovative phospholipid vesicles, namely glycerosomes, hyalurosomes and glycerol containing hyalurosomes, which were prepared using a high ratio of extract/phospholipid (1/3.5w/w). The in vitro biocompatibility of the nanoincorporated extract and its ability to potentiate the aptitude of the extract to counteract oxidative stress in skin cells were evaluated. The vesicles, especially glycerol containing hyalurosomes, were able to prevent oxidative damage and death of both keratinocytes and fibroblasts, promoting their viability.

  6. Evolution of metastasis revealed by mutational landscapes of chemically induced skin cancers

    Science.gov (United States)

    McCreery, Melissa Q; Halliwill, Kyle D; Chin, Douglas; Delrosario, Reyno; Hirst, Gillian; Vuong, Peter; Jen, Kuang-Yu; Hewinson, James; Adams, David J; Balmain, Allan

    2016-01-01

    Human tumors show a high level of genetic heterogeneity, but the processes that influence the timing and route of metastatic dissemination of the subclones are unknown. Here we have used whole-exome sequencing of 103 matched benign, malignant and metastatic skin tumors from genetically heterogeneous mice to demonstrate that most metastases disseminate synchronously from the primary tumor, supporting parallel rather than linear evolution as the predominant model of metastasis. Shared mutations between primary carcinomas and their matched metastases have the distinct A-to-T signature of the initiating carcinogen dimethylbenzanthracene, but non-shared mutations are primarily G-to-T, a signature associated with oxidative stress. The existence of carcinomas that either did or did not metastasize in the same host animal suggests that there are tumor-intrinsic factors that influence metastatic seeding. We also demonstrate the importance of germline polymorphisms in determining allele-specific mutations, and we identify somatic genetic alterations that are specifically related to initiation of carcinogenesis by Hras or Kras mutations. Mouse tumors that mimic the genetic heterogeneity of human cancers can aid our understanding of the clonal evolution of metastasis and provide a realistic model for the testing of novel therapies. PMID:26523969

  7. Contrasting effects of ultraviolet-A and ultraviolet B exposure on induction of contact sensitivity in human skin

    DEFF Research Database (Denmark)

    Skov, Lone; Hansen, Henrik; Barker, J. N.

    1997-01-01

    Ultraviolet-B (UVB), in addition to direct effects on DNA, induces immunological changes in the skin that predispose to the development of skin cancer. Whether ultraviolet-A (UVA) induces similar changes is unknown. This effect can be investigated in humans in vivo using epicutaneous antigens...

  8. Mass sensitivity analysis and designing of surface acoustic wave resonators for chemical sensors

    Science.gov (United States)

    Kshetrimayum, Roshan; Yadava, R. D. S.; Tandon, R. P.

    2009-05-01

    The sensitivity of surface acoustic wave (SAW) chemical sensors depends on several factors such as the frequency and phase point of SAW device operation, sensitivity of the SAW velocity to surface mass loading, sensitivity of the SAW oscillator resonance to the loop phase shift, film thickness and oscillator electronics. This paper analyzes the influence of the phase point of operation in SAW oscillator sensors based on two-port resonator devices. It is found that the mass sensitivity will be enhanced if the SAW device has a nonlinear dependence on the frequency (delay ~ frequency-1). This requires the device to generate and operate in a ωτg(ω) = const region in the device passband, where ω denotes the angular frequency of oscillation and τg(ω) denotes the phase slope of the SAW resonator device. A SAW coupled resonator filter (CRF) that take advantage of mode coupling is considered in realizing such a device to help in shaping the phase transfer characteristics of a high mass sensitivity sensor. The device design and simulation results are presented within the coupling-of-modes formalism.

  9. High Sensitivity, Low Power Nano Sensors and Devices for Chemical Sensing

    Science.gov (United States)

    Li, Jing; Powell, Dan; Getty, Stephanie; Lu, Yi-Jiang

    2004-01-01

    The chemical sensor market has been projected to grow to better than $40 billion dollars worldwide within the next 10 years. Some of the primary motivations to develop nanostructured chemical sensors are monitoring and control of environmental pollution; improved diagnostics for consumption; improvement in measurement precision and accuracy; and improved detection limits for Homeland security, battlefield environments, and process and quality control of industrial applications. In each of these applications, there is demand for sensitivity, selectivity and stability of environmental and biohazard detection and capture beyond what is currently commercially available. Nanotechnology offers the ability to work at the molecular level, atom by atom, to create large structures with fundamentally new molecular organization. It is essentially concerned with materials, devices, and systems whose structures and components exhibit novel and significantly improved physical, chemical and biological properties, phenomena, and process control due to their nanoscale size. One such nanotechnology-enabled chemical sensor has been developed at NASA Ames leveraging nanostructures, such as single walled carbon nanotubes (SWNTs) and metal oxide nanobelts or nanowires, as a sensing medium bridging a pair of interdigitated electrodes (IDE) realized through a silicon-based microfabrication and micromachining technique. The DE fingers are fabricated on a silicon substrate using standard photolithography and thin film metallization techniques. It is noteworthy that the fabrication techniques employed are not confined to the silicon substrate. Through spin casting and careful substrate selection (i.e. clothing, glass, polymer, etc.), additional degrees of freedom can be exploited to enhance sensitivity or to conform to unique applications. Both in-situ growth of nanostructured materials and casting of nanostructured dispersions were used to produce analogous chemical sensing devices.

  10. Chemical input and I-V output: stepwise chemical information processing in dye-sensitized solar cells.

    Science.gov (United States)

    Satoh, Norifusa; Han, Liyuan

    2012-12-14

    As a complex system, a dye-sensitized solar cell (DSC) exhibits emergent photovoltaics not obvious from the properties of the individual components. The chemical input of 4-tert-butylpyridine (TBP) into DSC improves the open circuit voltage (V(oc)) and reduces the short circuit current (I(sc)) in I-V output through multiple interactions with the components, yet it has been difficult to distinguish the multiple interactions and correlate the interactions with the influences on I-V output due to the complexity of the system. To deal with the multiple interactions, we have adapted a conceptual framework and methodology from coordination chemistry. First, we titrated the photovoltaic interface and electrolyte with TBP to identify the stepwise chemical interaction processes. An isopotential point observed in I-V output indicates that most of the inputted chemicals interact with the electrolyte. Cyclic voltammetric titration of the electrolyte demonstrates asymmetric redox peaks and two different isopotential points, indicating that the two-step coordination-decoordination process inhibits the reduction current of the electrolyte. Second, we set an interaction model bridging the hierarchical gaps between the multiple interactions and the I-V output to address the influences on outputs from the amount of the inputs. From the viewpoint of the interaction model and interactions observed, we are able to comprehend the processes of the complex system and suggest a direction to improve V(oc) without sacrificing I(sc) in DSCs. We conclude that the conceptual framework and methodology adapted from coordination chemistry is beneficial to enhance the emergent outputs of complex systems.

  11. GA(2)LEN skin test study I: GA(2)LEN harmonization of skin prick testing: novel sensitization patterns for inhalant allergens in Europe

    DEFF Research Database (Denmark)

    Heinzerling, L M; Burbach, G J; Edenharter, G

    2009-01-01

    BACKGROUND: Skin prick testing is the standard for diagnosing IgE-mediated allergies. However, different allergen extracts and different testing procedures have been applied by European allergy centres. Thus, it has been difficult to compare results from different centres or studies across Europe....... It was, therefore, crucial to standardize and harmonize procedures in allergy diagnosis and treatment within Europe. AIMS: The Global Asthma and Allergy European Network (GA(2)LEN), with partners and collaborating centres across Europe, was in a unique position to take on this task. The current study...

  12. Physico-chemical mechanism for the vapors sensitivity of photoluminescent InP quantum dots

    Science.gov (United States)

    Prosposito, P.; De Angelis, R.; De Matteis, F.; Hatami, F.; Masselink, W. T.; Zhang, H.; Casalboni, M.

    2016-03-01

    InP/InGaP surface quantum dots are interesting materials for optical chemical sensors since they present an intense emission at room temperature, whose intensity changes rapidly and reversibly depending on the composition of the environmental atmosphere. We present here their emission properties by time resolved photoluminescence spectroscopy investigation and we discuss the physico-chemical mechanism behind their sensitivity to the surrounding atmosphere. Photoluminescence transients in inert atmosphere (N2) and in solvent vapours of methanol, clorophorm, acetone and water were measured. The presence of vapors of clorophorm, acetone and water showed a very weak effect on the transient times, while an increase of up to 15% of the decay time was observed for methanol vapour exposure. On the basis of the vapor molecule nature (polarity, proticity, steric hindrance, etc.) and of the interaction of the vapor molecules with the quantum dots surface a sensing mechanism involving quantum dots non-radiative surface states is proposed.

  13. Modeling Chemical Detection Sensitivities of Active and Passive Remote Sensing Systems

    Energy Technology Data Exchange (ETDEWEB)

    Scharlemann, E T

    2003-07-28

    During nearly a decade of remote sensing programs under the auspices of the U. S. Department of Energy (DOE), LLNL has developed a set of performance modeling codes--called APRS--for both Active and Passive Remote Sensing systems. These codes emphasize chemical detection sensitivity in the form of minimum detectable quantities with and without background spectral clutter and in the possible presence of other interfering chemicals. The codes have been benchmarked against data acquired in both active and passive remote sensing programs at LLNL and Los Alamos National Laboratory (LANL). The codes include, as an integral part of the performance modeling, many of the data analysis techniques developed in the DOE's active and passive remote sensing programs (e.g., ''band normalization'' for an active system, principal component analysis for a passive system).

  14. Stepwise chemical reaction strategy for highly sensitive electrochemiluminescent detection of dopamine.

    Science.gov (United States)

    Zhang, Lei; Cheng, Yan; Lei, Jianping; Liu, Yueting; Hao, Qing; Ju, Huangxian

    2013-08-20

    A stepwise chemical reaction strategy based on the specific recognition of boronic acid to diol, and N-hydroxysuccinimide (NHS) ester to amine group, was designed to construct a "signal on" electrochemiluminescence (ECL) platform for highly sensitive detection of dopamine. A boronic acid-functionalized pyrene probe was synthesized and was self-assembled on the sidewalls of carbon nanotubes via π-π stacking interactions as capture probes on a glassy carbon electrode. Meanwhile, 3,3'-dithiodipropionic acid di(N-hydroxysuccinimide ester) (DSP)-functionalized CdTe quantum dots (QDs) were designed as signal probes and characterized with transmission electron microscopy and spectroscopic techniques. Upon stepwise chemical reaction of dopamine with boronic acid and then DSP-QDs, the QDs were captured on the electrode as ECL emitters for signal readout, leading to an ultralow background signal. By using O2 as an endogenous coreactant, the "signal on" ECL method was employed to quantify the concentration of dopamine from 50 pM to 10 nM with a detection limit of 26 pM. Moreover, the stepwise chemical reaction-based biosensor showed high specificity against cerebral interference and was successfully applied in the detection of dopamine in cerebrospinal fluid samples. The stepwise chemical reaction strategy should be a new concept for the design of highly selective analytical methods for the detection of small biomolecules.

  15. On the sensitivity, selectivity, sensory information and optimal size of resistive chemical sensors

    CERN Document Server

    Kish, L B; Heszler, P; Smulko, J; Granqvist, Claes-Goran; Heszler, Peter; Kish, Laszlo B.; Smulko, Janusz

    2007-01-01

    Information theoretical tools are applied for the study of the sensitivity and selectivity enhancements of resistive fluctuation-enhanced sensors. General considerations are given for the upper limit of selectivity enhancement. The signal-to-noise ratio and information channel capacity of fluctuation-enhanced chemical sensors is compared to that of classical sensors providing a single output. The considerations are done at the generic level with a few concrete examples and include the estimation of scaling relations between the sensor size, the signal power, the noise power and the speed of measurements versus the size, sampling rate and measurement time.

  16. Comparison of finite difference based methods to obtain sensitivities of stochastic chemical kinetic models.

    Science.gov (United States)

    Srivastava, Rishi; Anderson, David F; Rawlings, James B

    2013-02-21

    Sensitivity analysis is a powerful tool in determining parameters to which the system output is most responsive, in assessing robustness of the system to extreme circumstances or unusual environmental conditions, in identifying rate limiting pathways as a candidate for drug delivery, and in parameter estimation for calculating the Hessian of the objective function. Anderson [SIAM J. Numer. Anal. 50, 2237 (2012)] shows the advantages of the newly developed coupled finite difference (CFD) estimator over the common reaction path (CRP) [M. Rathinam, P. W. Sheppard, and M. Khammash, J. Chem. Phys. 132, 034103 (2010)] estimator. In this paper, we demonstrate the superiority of the CFD estimator over the common random number (CRN) estimator in a number of scenarios not considered previously in the literature, including the sensitivity of a negative log likelihood function for parameter estimation, the sensitivity of being in a rare state, and a sensitivity with fast fluctuating species. In all examples considered, the superiority of CFD over CRN is demonstrated. We also provide an example in which the CRN method is superior to the CRP method, something not previously observed in the literature. These examples, along with Anderson's results, lead to the conclusion that CFD is currently the best estimator in the class of finite difference estimators of stochastic chemical kinetic models.

  17. Relaxation of the chemical bond skin chemisorption size matter ZTP mechanics H2O myths

    CERN Document Server

    Sun, Chang Q

    2014-01-01

    The aim of this book is to explore the detectable properties of a material to the parameters of bond and non-bond involved and to clarify the interdependence of various properties. This book is composed of four parts; Part I deals with the formation and relaxation dynamics of bond and non-bond during chemisorptions with uncovering of the correlation among the chemical bond, energy band, and surface potential barrier (3B) during reactions; Part II is focused on the relaxation of bonds between atoms with fewer neighbors than the ideal in bulk with unraveling of the bond order-length-strength (BOLS) correlation mechanism, which clarifies the nature difference between nanostructures and bulk of the same substance; Part III deals with the relaxation dynamics of bond under heating and compressing with revealing of rules on the temperature-resolved elastic and plastic properties of low-dimensional materials; Part IV is focused on the asymmetric relaxation dynamics of the hydrogen bond (O:H-O) and the anomalous behav...

  18. Sensitivity enhancement of chemically amplified resists and performance study using extreme ultraviolet interference lithography

    Science.gov (United States)

    Buitrago, Elizabeth; Nagahara, Seiji; Yildirim, Oktay; Nakagawa, Hisashi; Tagawa, Seiichi; Meeuwissen, Marieke; Nagai, Tomoki; Naruoka, Takehiko; Verspaget, Coen; Hoefnagels, Rik; Rispens, Gijsbert; Shiraishi, Gosuke; Terashita, Yuichi; Minekawa, Yukie; Yoshihara, Kosuke; Oshima, Akihiro; Vockenhuber, Michaela; Ekinci, Yasin

    2016-07-01

    Extreme ultraviolet lithography (EUVL, λ=13.5 nm) is the most promising candidate to manufacture electronic devices for future technology nodes in the semiconductor industry. Nonetheless, EUVL still faces many technological challenges as it moves toward high-volume manufacturing (HVM). A key bottleneck from the tool design and performance point of view has been the development of an efficient, high-power EUV light source for high throughput production. Consequently, there has been extensive research on different methodologies to enhance EUV resist sensitivity. Resist performance is measured in terms of its ultimate printing resolution, line width roughness (LWR), sensitivity [S or best energy (BE)], and exposure latitude (EL). However, there are well-known fundamental trade-off relationships (line width roughness, resolution and sensitivity trade-off) among these parameters for chemically amplified resists (CARs). We present early proof-of-principle results for a multiexposure lithography process that has the potential for high sensitivity enhancement without compromising other important performance characteristics by the use of a "Photosensitized Chemically Amplified Resist™" (PSCAR™). With this method, we seek to increase the sensitivity by combining a first EUV pattern exposure with a second UV-flood exposure (λ=365 nm) and the use of a PSCAR. In addition, we have evaluated over 50 different state-of-the-art EUV CARs. Among these, we have identified several promising candidates that simultaneously meet sensitivity, LWR, and EL high-performance requirements with the aim of resolving line space (L/S) features for the 7- and 5-nm logic node [16- and 13-nm half-pitch (HP), respectively] for HVM. Several CARs were additionally found to be well resolved down to 12- and 11-nm HP with minimal pattern collapse and bridging, a remarkable feat for CARs. Finally, the performance of two negative tone state-of-the-art alternative resist platforms previously investigated

  19. A randomised, placebo-controlled trial of transcranial pulsed electromagnetic fields in patients with multiple chemical sensitivity

    DEFF Research Database (Denmark)

    Tran, Marie Thi Dao; Skovbjerg, Sine; Arendt-Nielsen, Lars

    2017-01-01

    OBJECTIVE: To evaluate the efficacy of transcranially applied pulsed electromagnetic fields (PEMF) on functional impairments and symptom severity in multiple chemical sensitivity (MCS) patients. METHODS: The study was conducted as a nationwide trial in Denmark using a randomised, parallel...

  20. Sensitivity and specificity analysis of fringing-field dielectric spectroscopy applied to a multi-layer system modelling the human skin

    Science.gov (United States)

    Huclova, Sonja; Baumann, Dirk; Talary, Mark S.; Fröhlich, Jürg

    2011-12-01

    The sensitivity and specificity of dielectric spectroscopy for the detection of dielectric changes inside a multi-layered structure is investigated. We focus on providing a base for sensing physiological changes in the human skin, i.e. in the epidermal and dermal layers. The correlation between changes of the human skin's effective permittivity and changes of dielectric parameters and layer thickness of the epidermal and dermal layers is assessed using numerical simulations. Numerical models include fringing-field probes placed directly on a multi-layer model of the skin. The resulting dielectric spectra in the range from 100 kHz up to 100 MHz for different layer parameters and sensor geometries are used for a sensitivity and specificity analysis of this multi-layer system. First, employing a coaxial probe, a sensitivity analysis is performed for specific variations of the parameters of the epidermal and dermal layers. Second, the specificity of this system is analysed based on the roots and corresponding sign changes of the computed dielectric spectra and their first and second derivatives. The transferability of the derived results is shown by a comparison of the dielectric spectra of a coplanar probe and a scaled coaxial probe. Additionally, a comparison of the sensitivity of a coaxial probe and an interdigitated probe as a function of electrode distance is performed. It is found that the sensitivity for detecting changes of dielectric properties in the epidermal and dermal layers strongly depends on frequency. Based on an analysis of the dielectric spectra, changes in the effective dielectric parameters can theoretically be uniquely assigned to specific changes in permittivity and conductivity. However, in practice, measurement uncertainties may degrade the performance of the system.

  1. Windows of Sensitivity to Toxic Chemicals in the Development of Cleft Palates.

    Science.gov (United States)

    Buser, M C; Pohl, H R

    2015-01-01

    Cleft lip and cleft palate are among the most common birth defects worldwide. There is a genetic component to the development of these malformations, as well as evidence that environmental exposures and prescription drug use may exacerbate or even produce these manifestations. Thus, it is important to understand the underlying mechanisms and when these exposures affect development of the growing fetus. The purpose of this investigation was to critically review the available literature related to orofacial cleft formation following chemical exposure and identify specific time frames for windows of sensitivity. Further, an aim was to evaluate the potential for predicting effects in humans based on animal studies. Evidence indicates that chemical causes of cleft palate development are due to dose and timing of exposure, susceptibility of the species (i.e., the genetic makeup), and mechanism of action. Several studies demonstrated that dose is a crucial factor; however, some investigators argued that even more important than dose was timing of exposure. Data show that the window of sensitivity to environmental teratogens in the development of cleft palates is quite narrow and follows closely the window of palatogenesis in the fetus of any given species.

  2. Prediction of cancer cell sensitivity to natural products based on genomic and chemical properties

    Directory of Open Access Journals (Sweden)

    Zhenyu Yue

    2015-11-01

    Full Text Available Natural products play a significant role in cancer chemotherapy. They are likely to provide many lead structures, which can be used as templates for the construction of novel drugs with enhanced antitumor activity. Traditional research approaches studied structure-activity relationship of natural products and obtained key structural properties, such as chemical bond or group, with the purpose of ascertaining their effect on a single cell line or a single tissue type. Here, for the first time, we develop a machine learning method to comprehensively predict natural products responses against a panel of cancer cell lines based on both the gene expression and the chemical properties of natural products. The results on two datasets, training set and independent test set, show that this proposed method yields significantly better prediction accuracy. In addition, we also demonstrate the predictive power of our proposed method by modeling the cancer cell sensitivity to two natural products, Curcumin and Resveratrol, which indicate that our method can effectively predict the response of cancer cell lines to these two natural products. Taken together, the method will facilitate the identification of natural products as cancer therapies and the development of precision medicine by linking the features of patient genomes to natural product sensitivity.

  3. Prediction of cancer cell sensitivity to natural products based on genomic and chemical properties.

    Science.gov (United States)

    Yue, Zhenyu; Zhang, Wenna; Lu, Yongming; Yang, Qiaoyue; Ding, Qiuying; Xia, Junfeng; Chen, Yan

    2015-01-01

    Natural products play a significant role in cancer chemotherapy. They are likely to provide many lead structures, which can be used as templates for the construction of novel drugs with enhanced antitumor activity. Traditional research approaches studied structure-activity relationship of natural products and obtained key structural properties, such as chemical bond or group, with the purpose of ascertaining their effect on a single cell line or a single tissue type. Here, for the first time, we develop a machine learning method to comprehensively predict natural products responses against a panel of cancer cell lines based on both the gene expression and the chemical properties of natural products. The results on two datasets, training set and independent test set, show that this proposed method yields significantly better prediction accuracy. In addition, we also demonstrate the predictive power of our proposed method by modeling the cancer cell sensitivity to two natural products, Curcumin and Resveratrol, which indicate that our method can effectively predict the response of cancer cell lines to these two natural products. Taken together, the method will facilitate the identification of natural products as cancer therapies and the development of precision medicine by linking the features of patient genomes to natural product sensitivity.

  4. Non-specific chemical inhibition of the Fanconi anemia pathway sensitizes cancer cells to cisplatin

    Directory of Open Access Journals (Sweden)

    Jacquemont Céline

    2012-04-01

    Full Text Available Abstract Background Platinum compounds such as cisplatin and carboplatin are DNA crosslinking agents widely used for cancer chemotherapy. However, the effectiveness of platinum compounds is often tempered by the acquisition of cellular drug resistance. Until now, no pharmacological approach has successfully overcome cisplatin resistance in cancer treatment. Since the Fanconi anemia (FA pathway is a DNA damage response pathway required for cellular resistance to DNA interstrand crosslinking agents, identification of small molecules that inhibit the FA pathway may reveal classes of chemicals that sensitize cancer cells to cisplatin. Results Through a cell-based screening assay of over 16,000 chemicals, we identified 26 small molecules that inhibit ionizing radiation and cisplatin-induced FANCD2 foci formation, a marker of FA pathway activity, in multiple human cell lines. Most of these small molecules also compromised ionizing radiation-induced RAD51 foci formation and homologous recombination repair, indicating that they are not selective toward the regulation of FANCD2. These compounds include known inhibitors of the proteasome, cathepsin B, lysosome, CHK1, HSP90, CDK and PKC, and several uncharacterized chemicals including a novel proteasome inhibitor (Chembridge compound 5929407. Isobologram analyses demonstrated that half of the identified molecules sensitized ovarian cancer cells to cisplatin. Among them, 9 demonstrated increased efficiency toward FA pathway-proficient, cisplatin-resistant ovarian cancer cells. Six small molecules, including bortezomib (proteasome inhibitor, CA-074-Me (cathepsin B inhibitor and 17-AAG (HSP90 inhibitor, synergized with cisplatin specifically in FA-proficient ovarian cancer cells (2008 + FANCF, but not in FA-deficient isogenic cells (2008. In addition, geldanamycin (HSP90 inhibitor and two CHK1 inhibitors (UCN-01 and SB218078 exhibited a significantly stronger synergism with cisplatin in FA

  5. Susceptibility of pRb-deficient epidermis to chemical skin carcinogenesis is dependent on the p107 allele dosage.

    Science.gov (United States)

    Santos, Mirentxu; Ruiz, Sergio; Lara, M Fernanda; Segrelles, Carmen; Moral, Marta; Martínez-Cruz, Ana Belén; Ballestín, Claudio; Lorz, Corina; García-Escudero, Ramón; Paramio, Jesús M

    2008-11-01

    Functional inactivation of the pRb-dependent pathway is a general feature of human cancer. However, only a reduced spectrum of tumors displays inactivation of the Rb gene. This can be attributed, at least partially, to the possible overlapping functions carried out by the related retinoblastoma family members p107 and p130. We observed that loss of pRb in epidermis, using the Cre/LoxP technology, results in proliferation and differentiation defects. These alterations are partially compensated by the elevation in the levels of p107. Moreover, epidermis lacking pRb and p107, but not pRb alone, develops spontaneous tumors, and double deficient primary keratinocytes are highly susceptible to Ha-ras-induced transformation. Two-stage chemical carcinogenesis experiments in mice lacking pRb in epidermis revealed a reduced susceptibility in papilloma formation and an increase in the malignant conversion. We have now explored whether the loss of one p107 allele, inducing a decrease in the levels of p107 up to normal levels could restore the susceptibility of pRb-deficient skin to two-stage protocol. We observed partial restoration in the incidence, number, and size of tumors. However, there is no increased malignancy despite sustained p53 activation. We also observed a partial reduction in the levels of proapoptotic proteins in benign papillomas. These data confirm our previous suggestions on the role of p107 as a tumor suppressor in epidermis in the absence of pRb.

  6. TIMES-SS - A promising tool for the assessment of skin sensitization hazard. A characterization with respect to the OECD validation principles for (Q)SARs and an external evaluation for predictivity

    DEFF Research Database (Denmark)

    Patlewicz, Grace; Dimitrov, Sabcho D.; Low, Lawrence K.;

    2007-01-01

    with an overall good concordance (83%) between experimental and predicted values. Further evaluation of these results highlighted certain inconsistencies which were rationalized by a consideration of reaction chemistry principles for sensitization. Improvements for TIMES-SS were proposed where appropriate. TIMES...... and to be scientifically valid in accordance with the OECD principles for (Q)SAR validation. TIMES-SS encodes structure-toxicity and structure-skin metabolism relationships through a number of transformations, some of which are underpinned by mechanistic 3D QSARs. Here, we describe the extent to which the five OECD...... principles are met and in particular the results from an external evaluation exercise that was recently carried out. As part of this exercise, data were generated for 40 new chemicals in the murine local lymph node assay (LLNA) and then compared with predictions made by TIMES-SS. The results were promising...

  7. Chemical biology drug sensitivity screen identifies sunitinib as synergistic agent with disulfiram in prostate cancer cells.

    Directory of Open Access Journals (Sweden)

    Kirsi Ketola

    Full Text Available BACKGROUND: Current treatment options for castration- and treatment-resistant prostate cancer are limited and novel approaches are desperately needed. Our recent results from a systematic chemical biology sensitivity screen covering most known drugs and drug-like molecules indicated that aldehyde dehydrogenase inhibitor disulfiram is one of the most potent cancer-specific inhibitors of prostate cancer cell growth, including TMPRSS2-ERG fusion positive cancers. However, the results revealed that disulfiram alone does not block tumor growth in vivo nor induce apoptosis in vitro, indicating that combinatorial approaches may be required to enhance the anti-neoplastic effects. METHODS AND FINDINGS: In this study, we utilized a chemical biology drug sensitivity screen to explore disulfiram mechanistic details and to identify compounds potentiating the effect of disulfiram in TMPRSS2-ERG fusion positive prostate cancer cells. In total, 3357 compounds including current chemotherapeutic agents as well as drug-like small molecular compounds were screened alone and in combination with disulfiram. Interestingly, the results indicated that androgenic and antioxidative compounds antagonized disulfiram effect whereas inhibitors of receptor tyrosine kinase, proteasome, topoisomerase II, glucosylceramide synthase or cell cycle were among compounds sensitizing prostate cancer cells to disulfiram. The combination of disulfiram and an antiangiogenic agent sunitinib was studied in more detail, since both are already in clinical use in humans. Disulfiram-sunitinib combination induced apoptosis and reduced androgen receptor protein expression more than either of the compounds alone. Moreover, combinatorial exposure reduced metastatic characteristics such as cell migration and 3D cell invasion as well as induced epithelial differentiation shown as elevated E-cadherin expression. CONCLUSIONS: Taken together, our results propose novel combinatorial approaches to inhibit

  8. Chemical Biology Drug Sensitivity Screen Identifies Sunitinib as Synergistic Agent with Disulfiram in Prostate Cancer Cells

    Science.gov (United States)

    Ketola, Kirsi; Kallioniemi, Olli; Iljin, Kristiina

    2012-01-01

    Background Current treatment options for castration- and treatment-resistant prostate cancer are limited and novel approaches are desperately needed. Our recent results from a systematic chemical biology sensitivity screen covering most known drugs and drug-like molecules indicated that aldehyde dehydrogenase inhibitor disulfiram is one of the most potent cancer-specific inhibitors of prostate cancer cell growth, including TMPRSS2-ERG fusion positive cancers. However, the results revealed that disulfiram alone does not block tumor growth in vivo nor induce apoptosis in vitro, indicating that combinatorial approaches may be required to enhance the anti-neoplastic effects. Methods and Findings In this study, we utilized a chemical biology drug sensitivity screen to explore disulfiram mechanistic details and to identify compounds potentiating the effect of disulfiram in TMPRSS2-ERG fusion positive prostate cancer cells. In total, 3357 compounds including current chemotherapeutic agents as well as drug-like small molecular compounds were screened alone and in combination with disulfiram. Interestingly, the results indicated that androgenic and antioxidative compounds antagonized disulfiram effect whereas inhibitors of receptor tyrosine kinase, proteasome, topoisomerase II, glucosylceramide synthase or cell cycle were among compounds sensitizing prostate cancer cells to disulfiram. The combination of disulfiram and an antiangiogenic agent sunitinib was studied in more detail, since both are already in clinical use in humans. Disulfiram-sunitinib combination induced apoptosis and reduced androgen receptor protein expression more than either of the compounds alone. Moreover, combinatorial exposure reduced metastatic characteristics such as cell migration and 3D cell invasion as well as induced epithelial differentiation shown as elevated E-cadherin expression. Conclusions Taken together, our results propose novel combinatorial approaches to inhibit prostate cancer cell

  9. A 4-year-old girl with manifestations of multiple chemical sensitivities.

    Science.gov (United States)

    Woolf, A

    2000-12-01

    Multiple chemical sensitivities (MCS) syndrome, also known as idiopathic environmental intolerance, is a controversial diagnosis that encompasses a wide range of waxing and waning, subjective symptoms referable to more than one body system and provoked by exposure to low levels of chemicals, foods, or other agents in the environment. Although MCS has been studied extensively, a unifying mechanism explaining the illness remains obscure, and clinicians are divided as to whether such a medical entity exists separately from psychosomatic syndromes. MCS is an adult diagnosis; there is little reference to pediatric cases in the scientific literature. In this case from the Pediatric Environmental Health Subspecialty Unit at Boston's Children's Hospital, I present the case of a preschool child who had suffered from milk allergy and poor weight gain as an infant, and then later developed asthma, allergic symptoms, sinusitis, headaches, fatigue, and rashes precipitated by an expanding variety of chemicals, foods, and allergens. I review definitions, mechanisms, diagnostic strategies, and management, and discuss some uniquely pediatric features of MCS as illustrated by this case.

  10. Sensitivity enhancement of chemically amplified resists and performance study using EUV interference lithography

    Science.gov (United States)

    Buitrago, Elizabeth; Nagahara, Seiji; Yildirim, Oktay; Nakagawa, Hisashi; Tagawa, Seiichi; Meeuwissen, Marieke; Nagai, Tomoki; Naruoka, Takehiko; Verspaget, Coen; Hoefnagels, Rik; Rispens, Gijsbert; Shiraishi, Gosuke; Terashita, Yuichi; Minekawa, Yukie; Yoshihara, Kosuke; Oshima, Akihiro; Vockenhuber, Michaela; Ekinci, Yasin

    2016-03-01

    Extreme ultraviolet lithography (EUVL, λ = 13.5 nm) is the most promising candidate to manufacture electronic devices for future technology nodes in the semiconductor industry. Nonetheless, EUVL still faces many technological challenges as it moves toward high-volume manufacturing (HVM). A key bottleneck from the tool design and performance point of view has been the development of an efficient, high power EUV light source for high throughput production. Consequently, there has been extensive research on different methodologies to enhance EUV resist sensitivity. Resist performance is measured in terms of its ultimate printing resolution, line width roughness (LWR), sensitivity (S or best energy BE) and exposure latitude (EL). However, there are well-known fundamental trade-off relationships (LRS trade-off) among these parameters for chemically amplified resists (CARs). Here we present early proof-of-principle results for a multi-exposure lithography process that has the potential for high sensitivity enhancement without compromising other important performance characteristics by the use of a Photosensitized Chemically Amplified Resist (PSCAR). With this method, we seek to increase the sensitivity by combining a first EUV pattern exposure with a second UV flood exposure (λ = 365 nm) and the use of a PSCAR. In addition, we have evaluated over 50 different state-of-the-art EUV CARs. Among these, we have identified several promising candidates that simultaneously meet sensitivity, LWR and EL high performance requirements with the aim of resolving line space (L/S) features for the 7 and 5 nm logic node (16 nm and 13 nm half-pitch HP, respectively) for HVM. Several CARs were additionally found to be well resolved down to 12 nm and 11 nm HP with minimal pattern collapse and bridging, a remarkable feat for CARs. Finally, the performance of two negative tone state-of-the-art alternative resist platforms previously investigated was compared to the CAR performance at and

  11. Sensitivity of two garden pea genotypes to physical and chemical mutagens

    Directory of Open Access Journals (Sweden)

    Slavka Kalapchieva

    2016-09-01

    Full Text Available A study on the sensitivity of two breeding lines of garden pea to mutagenic agents was carried out in the Maritsa Vegetable Crops Research Institute, Plovdiv. The purpose was to evaluate the sensitivity of the Pisum sativum L. genotypes to physical and chemical mutagens. In the experiment, the pea seeds were irradiated single or combined with 60Co gamma rays (40, 80, 100, 200 and 400 Gy and Ethyl methanesulfonate (EMS at concentrations of 0.1 and 0.2 %. Visible morphological changes of the stems and leaves were observed in plant of M1 generation, such as shorter stems, double petiole, clover-shaped leaves and a couple of tendrils. Single treatments with 100 Gy 60Co induced the highest mutation frequency M.F. = 7.69 for line 88-7, and М.F. = 2.11 for line 97-3, reported in M2 generation. Higher doses or combined gamma rays and EMS treatments induced more efficiently mutations. Line 88-7 was selected for further mutagenic treatment due to the higher sensitivity assessed.

  12. Electroconvulsive therapy substantially reduces symptom severity and social disability associated with multiple chemical sensitivity: a case report

    DEFF Research Database (Denmark)

    Elberling, Jesper; Gulmann, Nils; Rasmussen, Alice

    2010-01-01

    Multiple chemical sensitivity (MCS) is a chronic nonallergic, multisymptom disorder triggered by common environmental chemicals in concentrations considered nontoxic for most individuals. The condition may lead to loss of occupation and social isolation, and no effective treatment has been reported....... Electroconvulsive therapy (ECT) is a safe and effective treatment of severe depression and medical conditions such as chronic pain disorders....

  13. Evaluation of fibrin-based dermal-epidermal organotypic cultures for in vitro skin corrosion and irritation testing of chemicals according to OECD TG 431 and 439.

    Science.gov (United States)

    Morales, Mariana; Pérez, David; Correa, Luis; Restrepo, Luz

    2016-10-01

    Reconstructed human epidermis (RhE) models have been used for in vitro testing of the potential harmful effects of exposure to chemical compounds on health. In the past, skin irritation and corrosion were evaluated in animal models; however, in recent years, due to the bioethics implications of the method and, to minimize the use of experimental animals, alternative procedures have been proposed. The Organisation for Economic Co-operation and Development (OECD) in its test guidelines (TG) 431 and 439 indicates the requirements for validating new methods for the evaluation of skin corrosion and irritation, respectively. Here, we present an in-house human dermal-epidermal model, useful for the performance of these tests. Using the methods described in this work, it was possible to obtain human fibrin-based dermal-epidermal organotypic skin cultures (ORGs) displaying similar histological characteristics to native skin and expressing specific differentiation epithelial proteins. The end points to classify a substance as irritant or corrosive were cell viability evaluated by MTT assay, and cytokine release measured by BD CBA for human inflammatory cytokines. According to the MTT test, the ORGs correctly classified irritating and corrosive substances. Moreover, the cytokine release assay was difficult to interpret in the context of testing chemical hazard classification. Further experiments are needed to validate this new model for the evaluation of surfactants because the fibrin matrix was affected in the presence of these substances.

  14. High sensitivity detection and characterization of the chemical state of trace element contamination on silicon wafers

    CERN Document Server

    Pianetta, Piero A; Baur, K; Brennan, S; Homma, T; Kubo, N

    2003-01-01

    Increasing the speed and complexity of semiconductor integrated circuits requires advanced processes that put extreme constraints on the level of metal contamination allowed on the surfaces of silicon wafers. Such contamination degrades the performance of the ultrathin SiO sub 2 gate dielectrics that form the heart of the individual transistors. Ultimately, reliability and yield are reduced to levels that must be improved before new processes can be put into production. It should be noted that much of this metal contamination occurs during the wet chemical etching and rinsing steps required for the manufacture of integrated circuits and industry is actively developing new processes that have already brought the metal contamination to levels beyond the measurement capabilities of conventional analytical techniques. The measurement of these extremely low contamination levels has required the use of synchrotron radiation total reflection X-ray fluorescence (SR-TXRF) where sensitivities 100 times better than conv...

  15. Influenza viral membrane fusion is sensitive to sterol concentration but surprisingly robust to sterol chemical identity

    Science.gov (United States)

    Zawada, Katarzyna E.; Wrona, Dominik; Rawle, Robert J.; Kasson, Peter M.

    2016-01-01

    Influenza virions are enriched in cholesterol relative to the plasma membrane from which they bud. Previous work has shown that fusion between influenza virus and synthetic liposomes is sensitive to the amount of cholesterol in either the virus or the target membrane. Here, we test the chemical properties of cholesterol required to promote influenza fusion by replacing cholesterol with other sterols and assaying viral fusion kinetics. We find that influenza fusion with liposomes is surprisingly robust to sterol chemical identity, showing no significant dependence on sterol identity in target membranes for any of the sterols tested. In the viral membrane, lanosterol slowed fusion somewhat, while polar sterols produced a more pronounced slowing and inhibition of fusion. No other sterols tested showed a significant perturbation in fusion rates, including ones previously shown to alter membrane bending moduli or phase behavior. Although fusion rates depend on viral cholesterol, they thus do not require cholesterol’s ability to support liquid-liquid phase coexistence. Using electron cryo-microscopy, we further find that sterol-dependent changes to hemagglutinin spatial patterning in the viral membrane do not require liquid-liquid phase coexistence. We therefore speculate that local sterol-hemagglutinin interactions in the viral envelope may control the rate-limiting step of fusion. PMID:27431907

  16. The Search for Reliable Biomarkers of Disease in Multiple Chemical Sensitivity and Other Environmental Intolerances

    Directory of Open Access Journals (Sweden)

    Liudmila Korkina

    2011-07-01

    Full Text Available Whilst facing a worldwide fast increase of food and environmental allergies, the medical community is also confronted with another inhomogeneous group of environment-associated disabling conditions, including multiple chemical sensitivity (MCS, fibromyalgia, chronic fatigue syndrome, electric hypersensitivity, amalgam disease and others. These share the features of poly-symptomatic multi-organ cutaneous and systemic manifestations, with postulated inherited/acquired impaired metabolism of chemical/physical/nutritional xenobiotics, triggering adverse reactions at exposure levels far below toxicologically-relevant values, often in the absence of clear-cut allergologic and/or immunologic involvement. Due to the lack of proven pathogenic mechanisms generating measurable disease biomarkers, these environmental hypersensitivities are generally ignored by sanitary and social systems, as psychogenic or “medically unexplained symptoms”. The uncontrolled application of diagnostic and treatment protocols not corresponding to acceptable levels of validation, safety, and clinical efficacy, to a steadily increasing number of patients demanding assistance, occurs in many countries in the absence of evidence-based guidelines. Here we revise available information supporting the organic nature of these clinical conditions. Following intense research on gene polymorphisms of phase I/II detoxification enzyme genes, so far statistically inconclusive, epigenetic and metabolic factors are under investigation, in particular free radical/antioxidant homeostasis disturbances. The finding of relevant alterations of catalase, glutathione-transferase and peroxidase detoxifying activities significantly correlating with clinical manifestations of MCS, has recently registered some progress towards the identification of reliable biomarkers of disease onset, progression, and treatment outcomes.

  17. The search for reliable biomarkers of disease in multiple chemical sensitivity and other environmental intolerances.

    Science.gov (United States)

    De Luca, Chiara; Raskovic, Desanka; Pacifico, Valeria; Thai, Jeffrey Chung Sheun; Korkina, Liudmila

    2011-07-01

    Whilst facing a worldwide fast increase of food and environmental allergies, the medical community is also confronted with another inhomogeneous group of environment-associated disabling conditions, including multiple chemical sensitivity (MCS), fibromyalgia, chronic fatigue syndrome, electric hypersensitivity, amalgam disease and others. These share the features of poly-symptomatic multi-organ cutaneous and systemic manifestations, with postulated inherited/acquired impaired metabolism of chemical/physical/nutritional xenobiotics, triggering adverse reactions at exposure levels far below toxicologically-relevant values, often in the absence of clear-cut allergologic and/or immunologic involvement. Due to the lack of proven pathogenic mechanisms generating measurable disease biomarkers, these environmental hypersensitivities are generally ignored by sanitary and social systems, as psychogenic or "medically unexplained symptoms". The uncontrolled application of diagnostic and treatment protocols not corresponding to acceptable levels of validation, safety, and clinical efficacy, to a steadily increasing number of patients demanding assistance, occurs in many countries in the absence of evidence-based guidelines. Here we revise available information supporting the organic nature of these clinical conditions. Following intense research on gene polymorphisms of phase I/II detoxification enzyme genes, so far statistically inconclusive, epigenetic and metabolic factors are under investigation, in particular free radical/antioxidant homeostasis disturbances. The finding of relevant alterations of catalase, glutathione-transferase and peroxidase detoxifying activities significantly correlating with clinical manifestations of MCS, has recently registered some progress towards the identification of reliable biomarkers of disease onset, progression, and treatment outcomes.

  18. [Idiopathic environmental intolerance (IPI)--formerly multiple chemical sensitivity (MCS)--from the psychiatric perspective].

    Science.gov (United States)

    Blaschko, S; Zilker, T; Förstl, H

    1999-04-01

    The term "idiopathic environmental intolerances" (IEI)/"multiple chemical sensitivities" (MCS) is used to describe a complex of heterogeneous somatic symptoms without a diagnosable organic disease. Symptoms are believed to be triggered by exposure to low levels of environmental chemicals that are usually well tolerated by the general population. There is no widely accepted definition for the phenomenon. A number of contradictory etiologic hypotheses and therapeutic concepts are discussed. One of the crucial questions is whether IEI/MCS should be understood as an own entity of disease. It has been demonstrated that a majority of patients with IEI/MCS meet diagnostic criteria for psychiatric diseases. Most frequently, somatoform, affective and anxiety disorders can be diagnosed. Therefore, psychiatric and psychotherapeutic therapy seems appropriate. The present paper provides a review of the different case definitions, etiologic and therapeutic concepts and of studies examining the frequency of psychiatric morbidity in patients with IEI/MCS. Additionally, a diagnostic algorithm and a concept of behavioral therapy for IEI/MCS patients with somatoform disorders are described.

  19. Central neurological abnormalities and multiple chemical sensitivity caused by chronic toluene exposure.

    Science.gov (United States)

    Lee, Y-L; Pai, M-C; Chen, J-H; Guo, Y L

    2003-10-01

    Multiple chemical sensitivity (MCS) is a syndrome in which multiple symptoms occur with low-level chemical exposure; whether it is an organic disease initiated by environmental exposure or a psychological disorder is still controversial. We report a 38-year-old male worker with chronic toluene exposure who developed symptoms such as palpitation, insomnia, dizziness with headache, memory impairment, euphoria while working, and depression during the weekend. Upon cessation of exposure, follow-up neurobehavioural tests, including the cognitive ability screening instrument and the mini-mental state examination, gradually improved and eventually became normal. Although no further toluene exposure was noted, non-specific symptoms reappeared whenever the subject smelled automotive exhaust fumes or paint, or visited a petrol station, followed by anxiety with sleep disturbance. During hospitalization for a toluene provocation test, there was no difference between pre-challenge and post-challenge PaCO(2), PaO(2), SaO(2) or pulmonary function tests, except some elevation of pulse rate. The clinical manifestations suggested that MCS was more relevant to psychophysiological than pathophysiological factors.

  20. Progress in resolution, sensitivity, and critical dimensional uniformity of EUV chemically amplified resists

    Science.gov (United States)

    Thackeray, James; Cameron, James; Jain, Vipul; LaBeaume, Paul; Coley, Suzanne; Ongayi, Owendi; Wagner, Mike; Rachford, Aaron; Biafore, John

    2013-03-01

    This paper will discuss further progress obtained at Dow for the improvement of the Resolution, Contact critical dimension uniformity(CDU), and Sensitivity of EUV chemically amplified resists. For resolution, we have employed the use of polymer-bound photoacid generator (PBP) concept to reduce the intrinsic acid diffusion that limits the ultimate resolving capability of CA resists. For CDU, we have focused on intrinsic dissolution contrast and have found that the photo-decomposable base (PDB) concept can be successfully employed. With the use of a PDB, we can reduce CDU variation at a lower exposure energy. For sensitivity, we have focused on more efficient EUV photon capture through increased EUV absorption, as well as more highly efficient PAGs for greater acid generating efficiency. The formulation concepts will be confirmed using Prolith stochastic resist modeling. For the 26nm hp contact holes, we get excellent overall process window with over 280nm depth of focus for a 10% exposure latitude Process window. The 1sigma Critical dimension uniformity [CDU] is 1.1 nm. We also obtain 20nm hp contact resolution in one of our new EUV resists.

  1. A new type of functional chemical sensitizer MgH2 for improving pressure desensitization resistance of emulsion explosives

    Science.gov (United States)

    Cheng, Y. F.; Yan, S. L.; Ma, H. H.; Shen, Z. W.; Liu, R.

    2016-03-01

    In millisecond-delay blasting and deep water blasting projects, traditional emulsion explosives sensitized by the chemical sensitizer NaNO2 often encounter incomplete explosion or misfire problems because of the "pressure desensitization" phenomenon, which seriously affects blasting safety and construction progress. A MgH2-sensitized emulsion explosive was invented to solve these problems. Experimental results show that MgH2 can effectively reduce the problem of pressure desensitization. In this paper, the factors which influence the pressure desensitization of two types of emulsion explosives are studied, and resistance to this phenomenon of MgH2-sensitized emulsion explosives is discussed.

  2. Sensitivity of transatlantic dust transport to chemical aging and related atmospheric processes

    KAUST Repository

    Abdelkader, Mohamed

    2017-03-20

    We present a sensitivity study on transatlantic dust transport, a process which has many implications for the atmosphere, the ocean and the climate. We investigate the impact of key processes that control the dust outflow, i.e., the emission flux, convection schemes and the chemical aging of mineral dust, by using the EMAC model following Abdelkader et al. (2015). To characterize the dust outflow over the Atlantic Ocean, we distinguish two geographic zones: (i) dust interactions within the Intertropical Convergence Zone (ITCZ), or the dust–ITCZ interaction zone (DIZ), and (ii) the adjacent dust transport over the Atlantic Ocean (DTA) zone. In the latter zone, the dust loading shows a steep and linear gradient westward over the Atlantic Ocean since particle sedimentation is the dominant removal process, whereas in the DIZ zone aerosol–cloud interactions, wet deposition and scavenging processes determine the extent of the dust outflow. Generally, the EMAC simulated dust compares well with CALIPSO observations; however, our reference model configuration tends to overestimate the dust extinction at a lower elevation and underestimates it at a higher elevation. The aerosol optical depth (AOD) over the Caribbean responds to the dust emission flux only when the emitted dust mass is significantly increased over the source region in Africa by a factor of 10. These findings point to the dominant role of dust removal (especially wet deposition) in transatlantic dust transport. Experiments with different convection schemes have indeed revealed that the transatlantic dust transport is more sensitive to the convection scheme than to the dust emission flux parameterization. To study the impact of dust chemical aging, we focus on a major dust outflow in July 2009. We use the calcium cation as a proxy for the overall chemical reactive dust fraction and consider the uptake of major inorganic acids (i.e., H2SO4, HNO3 and HCl) and their anions, i.e., sulfate (SO42−), bisulfate

  3. The use of ex vivo human skin tissue for genotoxicity testing

    Energy Technology Data Exchange (ETDEWEB)

    Reus, Astrid A.; Usta, Mustafa [TNO Triskelion BV, Utrechtseweg 48, 3704 HE, Zeist (Netherlands); Krul, Cyrille A.M., E-mail: cyrille.krul@tno.nl [TNO, Utrechtseweg 48, 3704 HE Zeist (Netherlands)

    2012-06-01

    As a result of the chemical legislation concerning the registration, evaluation, authorization and restriction of chemicals (REACH), and the Seventh Amendment to the Cosmetics Directive, which prohibits animal testing in Europe for cosmetics, alternative methods for safety evaluation of chemicals are urgently needed. Current in vitro genotoxicity assays are not sufficiently predictive for the in vivo situation, resulting in an unacceptably high number of misleading positives. For many chemicals and ingredients of personal care products the skin is the first site of contact, but there are no in vitro genotoxicity assays available in the skin for additional evaluation of positive or equivocal responses observed in regulatory in vitro genotoxicity assays. In the present study ex vivo human skin tissue obtained from surgery was used for genotoxicity evaluation of chemicals by using the comet assay. Fresh ex vivo human skin tissue was cultured in an air–liquid interface and topically exposed to 20 chemicals, including true positive, misleading positive and true negative genotoxins. Based on the results obtained in the present study, the sensitivity, specificity and accuracy of the ex vivo skin comet assay to predict in vivo genotoxicity were 89%, 90% and 89%, respectively. Donor and experimental variability were mainly reflected in the magnitude of the response and not the difference between the presence and absence of a genotoxic response. The present study indicates that human skin obtained from surgery is a promising and robust model for safety evaluation of chemicals that are in direct contact with the skin. -- Highlights: ► We use human skin obtained from surgery for genotoxicity evaluation of chemicals. ► We use the comet assay as parameter for genotoxicity in ex vivo human skin. ► Sensitivity, specificity and accuracy to predict in vivo genotoxins are determined. ► Sensitivity, specificity and accuracy are 89%, 90% and 90%, respectively. ► The method

  4. Adverse and beneficial effects of plant extracts on skin and skin disorders.

    Science.gov (United States)

    Mantle, D; Gok, M A; Lennard, T W

    2001-06-01

    Plants are of relevance to dermatology for both their adverse and beneficial effects on skin and skin disorders respectively. Virtually all cultures worldwide have relied historically, or continue to rely on medicinal plants for primary health care. Approximately one-third of all traditional medicines are for treatment of wounds or skin disorders, compared to only 1-3% of modern drugs. The use of such medicinal plant extracts for the treatment of skin disorders arguably has been based largely on historical/anecdotal evidence, since there has been relatively little data available in the scientific literature, particularly with regard to the efficacy of plant extracts in controlled clinical trials. In this article therefore, adverse and beneficial aspects of medicinal plants relating to skin and skin disorders have been reviewed, based on recently available information from the peer-reviewed scientific literature. Beneficial aspects of medicinal plants on skin include: healing of wounds and burn injuries (especially Aloe vera); antifungal, antiviral, antibacterial and acaricidal activity against skin infections such as acne, herpes and scabies (especially tea tree (Melaleuca alternifolia) oil); activity against inflammatory/immune disorders affecting skin (e.g. psoriasis); and anti-tumour promoting activity against skin cancer (identified using chemically-induced two-stage carcinogenesis in mice). Adverse effects of plants on skin reviewed include: irritant contact dermatitis caused mechanically (spines, irritant hairs) or by irritant chemicals in plant sap (especially members of the Ranunculaceae, Euphorbiaceae and Compositae plant families); phytophotodermatitis resulting from skin contamination by plants containing furocoumarins, and subsequent exposure to UV light (notably members of the Umbelliferae and Rutaceae plant families); and immediate (type I) or delayed hypersensitivity contact reactions mediated by the immune system in individuals sensitized to plants

  5. Skin Diseases: Skin Health and Skin Diseases

    Science.gov (United States)

    Skip Navigation Bar Home Current Issue Past Issues Skin Diseases Skin Health and Skin Diseases Past Issues / Fall 2008 Table of Contents ... acne to wrinkles Did you know that your skin is the largest organ of your body? It ...

  6. BIOSENSING TECHNICS FOR HUMAN DETECTION. 1. THE FROG SKIN TRANSDUCER: PRELIMINARY EXPERIMENT

    Science.gov (United States)

    Isolated frog skin used as a transducer whose bioelectrical potential is measured as a function of chemical species and concentration, is shown to...log units. A high degree of variability of response between frog skins, and a lack of data on ultimate sensitivities at usefully low levels for selected substances, are major problems that remain to be examined.

  7. Chemical management in fungicide sensitivity of Mycosphaerella fijiensis collected from banana fields in México.

    Science.gov (United States)

    Aguilar-Barragan, Alejandra; García-Torres, Ana Elisa; Odriozola-Casas, Olga; Macedo-Raygoza, Gloria; Ogura, Tetsuya; Manzo-Sánchez, Gilberto; James, Andrew C; Islas-Flores, Ignacio; Beltrán-García, Miguel J

    2014-01-01

    The chemical management of the black leaf streak disease in banana caused by Mycosphaerella fijiensis (Morelet) requires numerous applications of fungicides per year. However this has led to fungicide resistance in the field. The present study evaluated the activities of six fungicides against the mycelial growth by determination of EC50 values of strains collected from fields with different fungicide management programs: Rustic management (RM) without applications and Intensive management (IM) more than 25 fungicide application/year. Results showed a decreased sensitivity to all fungicides in isolates collected from IM. Means of EC50 values in mg L(-1) for RM and IM were: 13.25 ± 18.24 and 51.58 ± 46.14 for azoxystrobin, 81.40 ± 56.50 and 1.8575 ± 2.11 for carbendazim, 1.225 ± 0.945 and 10.01 ± 8.55 for propiconazole, 220 ± 67.66 vs. 368 ± 62.76 for vinclozolin, 9.862 ± 3.24 and 54.5 ± 21.08 for fludioxonil, 49.2125 ± 34.11 and 112.25 ± 51.20 for mancozeb. A molecular analysis for β-tubulin revealed a mutation at codon 198 in these strains having an EC50 greater than 10 mg L(-1) for carbendazim. Our data indicate a consistency between fungicide resistance and intensive chemical management in banana fields, however indicative values for resistance were also found in strains collected from rustic fields, suggesting that proximity among fields may be causing a fungus interchange, where rustic fields are breeding grounds for development of resistant strains. Urgent actions are required in order to avoid fungicide resistance in Mexican populations of M. fijiensis due to fungicide management practices.

  8. General practitioners’ experiences with provision of healthcare to patients with self-reported multiple chemical sensitivity

    Science.gov (United States)

    Skovbjerg, Sine; Johansen, Jeanne Duus; Rasmussen, Alice; Thorsen, Hanne; Elberling, Jesper

    2009-01-01

    Objective To describe general practitioners’ (GPs’) evaluation of and management strategies in relation to patients who seek medical advice because of multiple chemical sensitivity (MCS). Design A nationwide cross-sectional postal questionnaire survey. The survey included a sample of 1000 Danish GPs randomly drawn from the membership list of GPs in the Danish Medical Association. Setting Denmark. Results Completed questionnaires were obtained from 691 GPs (69%). Within the last 12 months 62.4% (n = 431) of the GPs had been consulted by at least one patient with MCS. Of these, 55.2% of the GPs evaluated the patients’ complaints as chronic and 46.2% stated that they were rarely able to meet the patients’ expectations for healthcare. The majority, 73.5%, had referred patients to other medical specialties. The cause of MCS was perceived as multi-factorial by 64.3% of the GPs, as somatic/biologic by 27.6%, and as psychological by 7.2%. Partial or complete avoidance of chemical exposures was recommended by 86.3%. Clinical guidelines, diagnostic tools, or more insight in the pathophysiology were requested by 84.5% of the GPs. Conclusion Despite the lack of formal diagnostic labelling the patient with MCS is well known by GPs. The majority of the GPs believed that MCS primarily has a multi-factorial explanation. However, perceptions of the course of the condition and management strategies differed, and many GPs found it difficult to meet the patients’ expectations for healthcare. The majority of the GPs requested more knowledge and clinical guidelines for the management of this group of patients. PMID:19452353

  9. Chemical skin defence in the Eastern fire-bellied toad Bombina orientalis: an ultrastructural approach to the mechanism of poison gland rehabilitation after discharge

    Directory of Open Access Journals (Sweden)

    Sara Quagliata

    2008-12-01

    Full Text Available Type I serous glands in the skin of the Eastern yellow-bellied toad Bombina orientalis released their product massively after 10-3 M nor-adrenalin (NA stimulation, mimicking orthosympathetic control on poison emission in chemical skin defence. Features of cutaneous glands involved in this bulk discharge were observed under light and electron microscopes. Furthermore, restoration of depleted glands was followed after 1, 2 and 3 weeks, and compared with serous biosynthesis during larval gland development. Bulk discharge was caused by contraction of myoepithelial cells (mecs encircling the secretory units. Mec compression dramatically affected the secretory unit, but parts of this syncytial cytoplasm were saved from degeneration and cooperated in gland renewal with stem cells from the gland neck. These adenoblasts underwent proliferation and secretory cytodifferentiation, until merging with the syncytium. Cytoplasm that had resumed secretory activity showed the features typical of larval gland development: the endoplasmic reticulum (rer cisterns were aligned in close parallel arrangement and Golgi stacks released minute type I granules. Secretory rehabilitation led to increasing amounts of granule content. In the meantime, rough cisterns decreased in number and assumed the less ordered pattern described in control specimens. Data collected in the present study revealed that chemical skin defence in anurans is a multi-factorial mechanism involving specific activities: mechanical from mecs, biosynthetic from secretory syncytium and proliferative from intercalated stem cells.

  10. Overcoming computational uncertainties to reveal chemical sensitivity in single molecule conduction calculations.

    Science.gov (United States)

    Solomon, Gemma C; Reimers, Jeffrey R; Hush, Noel S

    2005-06-01

    In the calculation of conduction through single molecule's approximations about the geometry and electronic structure of the system are usually made in order to simplify the problem. Previously [G. C. Solomon, J. R. Reimers, and N. S. Hush, J. Chem. Phys. 121, 6615 (2004)], we have shown that, in calculations employing cluster models for the electrodes, proper treatment of the open-shell nature of the clusters is the most important computational feature required to make the results sensitive to variations in the structural and chemical features of the system. Here, we expand this and establish a general hierarchy of requirements involving treatment of geometrical approximations. These approximations are categorized into two classes: those associated with finite-dimensional methods for representing the semi-infinite electrodes, and those associated with the chemisorption topology. We show that ca. 100 unique atoms are required in order to properly characterize each electrode: using fewer atoms leads to nonsystematic variations in conductivity that can overwhelm the subtler changes. The choice of binding site is shown to be the next most important feature, while some effects that are difficult to control experimentally concerning the orientations at each binding site are actually shown to be insignificant. Verification of this result provides a general test for the precision of computational procedures for molecular conductivity. Predictions concerning the dependence of conduction on substituent and other effects on the central molecule are found to be meaningful only when they exceed the uncertainties of the effects associated with binding-site variation.

  11. Multiple chemical sensitivity and workplace discrimination: the national EEOC ADA research project.

    Science.gov (United States)

    Vierstra, Courtney V; Rumrill, Phillip D; Koch, Lynn C; McMahon, Brian T

    2007-01-01

    Information from the Integrated Mission System of the United States Equal Employment Opportunity Commission (EEOC) was used to investigate the employment discrimination experiences of Americans with multiple chemical sensitivity (MCS) in comparison to Americans in a general disability group with allergies, asthma, HIV, gastrointestinal impairment, cumulative trauma disorder and tuberculosis. Specifically, the researchers examined demographic characteristics of the charging parties; the industry designation, location, and size of employers against whom allegations were filed; the nature of discrimination (i.e., type of adverse action) alleged to occur; and the legal outcomes or resolutions of these allegations. Findings indicate that persons with MCS were, on average, older than the comparison group and comparatively overrepresented by Caucasians and women. People with MCS were proportionally more likely than the comparison group to allege discrimination related to reasonable accommodations. People with MCS were proportionally more likely than the comparison group to file allegations against employers in the manufacturing and public administration industries, employers with 201-500 workers, and employers in the Western Census region. People with MCS were proportionally more likely than the comparison group to receive non-merit resolutions as a result of the EEOC's Americans with Disabilities Act Title I investigatory process. Implications for policy and advocacy are addressed.

  12. Chemical Characterization and Toxicologic Evaluation of Airborne Mixtures. Tumorigenicity Studies of Diesel Fuel-2, Red Smoke Dye and Violet Smoke Dyes in the SENCAR Mouse Skin Tumorigenesis Bioassay System

    Science.gov (United States)

    1985-09-01

    nitrosamides, sulfonates, sultones, and ureas. The 32 chemicals listed in Table 1 include such well known chemical carcino- gens as aflatoxin BI, bis...direct or indirect carcinogen at a subthreshold dose and is essentially irreversible. The promotion phase requires repetitive treatments after...34by initiators of mouse skin tumorigenesis. Cancer Res. 29: 510-514. Hennings, H., B. Michael, and E. Patterson. 1978. Croton oil enhancement of skin

  13. PH Sensitive Polymers for Improving Reservoir Sweep and Conformance Control in Chemical Flooring

    Energy Technology Data Exchange (ETDEWEB)

    Mukul Sharma; Steven Bryant; Chun Huh

    2008-03-31

    There is an increasing opportunity to recover bypassed oil from depleted, mature oilfields in the US. The recovery factor in many reservoirs is low due to inefficient displacement of the oil by injected fluids (typically water). The use of chemical flooding methods to increase recovery efficiencies is severely constrained by the inability of the injected chemicals to contact the bypassed oil. Low sweep efficiencies are the primary cause of low oil recoveries observed in the field in chemical flooding operations even when lab studies indicate high oil recovery efficiency. Any technology that increases the ability of chemical flooding agents to better contact the remaining oil and reduce the amount of water produced in conjunction with the produced oil will have a significant impact on the cost of producing oil domestically in the US. This translates directly into additional economically recoverable reserves, which extends the economic lives of marginal and mature wells. The objective of this research project was to develop a low-cost, pH-triggered polymer for use in IOR processes to improve reservoir sweep efficiency and reservoir conformance in chemical flooding. Rheological measurements made on the polymer solution, clearly show that it has a low viscosity at low pH and exhibits a sudden increase in viscosity (by 2 orders of magnitude or more) at a pH of 3.5 to 4. This implies that the polymer would preferentially flow into zones containing water since the effective permeability to water is highest in these zones. As the pH of the zone increases due to the buffering capacity of the reservoir rock, the polymer solution undergoes a liquid to gel transition causing a sharp increase in the viscosity of the polymer solution in these zones. This allows operationally robust, in-depth conformance treatment of such water bearing zones and better mobility control. The rheological properties of HPAM solutions were measured. These include: steady-shear viscosity and

  14. [The non-specific environmental syndromes MCS (Multiple Chemical Sensitivity), IEI (Idiopathic Environmental Intolerance) and SBS (Sick Building Syndrome)].

    Science.gov (United States)

    Csef, H

    1998-11-30

    This review starts with a clinical description of the most common unspecific environmental diseases, such as Multiple Chemical Sensitivities (MCS), Idiopathic Environmental Intolerances (IEI) and Sick Building Syndrome (SBS). These syndromes are very controversial discussed between scientific medicine and "clinical ecology". In addition, they have fundamental similarities to Chronic Fatigue Syndrome (CFS) and Fibromyalgia. Finally the spectrum of therapeutic approaches is discussed.

  15. Lack of contralateral suppression in transient-evoked otoacoustic emissions in multiple chemical sensitivity: a clinical correlation study

    Directory of Open Access Journals (Sweden)

    Alessandro Micarelli

    2016-01-01

    Full Text Available Multiple chemical sensitivity (MCS is a chronic disorder characterized by a variety of symptoms associated with the exposure to chemicals at a concentration below the toxic level. Previous studies have demonstrated peculiar responses in brain activity in these patients with respect to sensory stimuli while the association between chemical sensitivity and other environmental intolerances such as noise sensitivity has been questioned by researchers. In this study, a cohort of 18 MCS patients underwent transient-evoked otoacoustic emission (TEOAE testing with and without contralateral suppression to evaluate the functionality of the medial olivocochlear (MOC reflex involved in speech-in-noise sensitivity. Results were compared with an age- and gender-matched control group (n = 20 and correlation analysis with disease onset and quick environmental exposure sensitivity inventory (qEESI symptom severity scale was performed. Subjects affected by MCS showed statistically significant impairment of MOC reflex, and the onset of the disease and several symptom subscales showed to be correlated to such reduction in some of the frequencies tested. These data suggest that alterations of MOC reflex could be part of the complex features of this disease although more studies are needed to further explore auditory perception disorders in environmental intolerances.

  16. Theoretical study of relationships among resolution, line width roughness, and sensitivity of chemically amplified extreme ultraviolet resists with photodecomposable quenchers

    Science.gov (United States)

    Kozawa, Takahiro; Santillan, Julius Joseph; Itani, Toshiro

    2016-11-01

    The resolution of chemically amplified extreme ultraviolet (EUV) resists has reached 13-15 nm. However, the line width roughness (LWR) and sensitivity are still inadequate for their application to the high-volume production of semiconductor devices. In this study, the performance of chemically amplified resists with photodecomposable quenchers were investigated by simulation based on the sensitization and reaction mechanisms of chemically amplified EUV resists. The relationships among resolution, LWR, and sensitivity were evaluated in the half-pitch ranges of 12-16 nm. The requirements for 20 mJ cm-2 and 10% critical dimension (CD) LWR are considered to be within the physical limits in the half-pitch range of 12-16 nm when an optical image with a contrast of 1 (normalized image log slope of π) is given. Depending on the given image quality and the required sensitivity, the optimization of sensitizer concentration and the increase in resist absorption coefficient and/or effective reaction radius for deprotection are required to achieve 10% CD LWR.

  17. PH Sensitive Polymers for Improving Reservoir Sweep and Conformance Control in Chemical Flooring

    Energy Technology Data Exchange (ETDEWEB)

    Mukul Sharma; Steven Bryant; Chun Huh

    2008-03-31

    There is an increasing opportunity to recover bypassed oil from depleted, mature oilfields in the US. The recovery factor in many reservoirs is low due to inefficient displacement of the oil by injected fluids (typically water). The use of chemical flooding methods to increase recovery efficiencies is severely constrained by the inability of the injected chemicals to contact the bypassed oil. Low sweep efficiencies are the primary cause of low oil recoveries observed in the field in chemical flooding operations even when lab studies indicate high oil recovery efficiency. Any technology that increases the ability of chemical flooding agents to better contact the remaining oil and reduce the amount of water produced in conjunction with the produced oil will have a significant impact on the cost of producing oil domestically in the US. This translates directly into additional economically recoverable reserves, which extends the economic lives of marginal and mature wells. The objective of this research project was to develop a low-cost, pH-triggered polymer for use in IOR processes to improve reservoir sweep efficiency and reservoir conformance in chemical flooding. Rheological measurements made on the polymer solution, clearly show that it has a low viscosity at low pH and exhibits a sudden increase in viscosity (by 2 orders of magnitude or more) at a pH of 3.5 to 4. This implies that the polymer would preferentially flow into zones containing water since the effective permeability to water is highest in these zones. As the pH of the zone increases due to the buffering capacity of the reservoir rock, the polymer solution undergoes a liquid to gel transition causing a sharp increase in the viscosity of the polymer solution in these zones. This allows operationally robust, in-depth conformance treatment of such water bearing zones and better mobility control. The rheological properties of HPAM solutions were measured. These include: steady-shear viscosity and

  18. Advantages of chemical exchange-sensitive spin-lock (CESL) over chemical exchange saturation transfer (CEST) for hydroxyl- and amine-water proton exchange studies.

    Science.gov (United States)

    Jin, Tao; Kim, Seong-Gi

    2014-11-01

    The chemical exchange (CE) rate of endogenous hydroxyl and amine protons with water is often comparable to the difference in their chemical shifts. These intermediate exchange processes have been imaged by the CE saturation transfer (CEST) approach with low-power and long-duration irradiation. However, the sensitivity is not optimal and, more importantly, the signal is contaminated by slow magnetization transfer processes. Here, the properties of CEST signals are compared with those of a CE-sensitive spin-lock (CESL) technique irradiating at the labile proton frequency. First, using a higher power and shorter irradiation in CE-MRI, we obtain: (i) an increased selectivity to faster CE rates via a higher sensitivity to faster CEs and a lower sensitivity to slower CEs and magnetization transfer processes; and (ii) a decreased in vivo asymmetric magnetization transfer contrast measured at ±15 ppm. The sensitivity gain of CESL over CEST is higher for a higher power and shorter irradiation. Unlike CESL, CEST signals oscillate at a very high power and short irradiation. Second, time-dependent CEST and CESL signals are well modeled by analytical solutions of CE-MRI with an asymmetric population approximation, which can be used for quantitative CE-MRI and validated by simulations of Bloch-McConnell equations and phantom experiments. Finally, the in vivo amine-water proton exchange contrast measured at 2.5 ppm with ω1 = 500 Hz is 18% higher in sensitivity for CESL than CEST at 9.4 T. Overall, CESL provides better exchange rate selectivity and sensitivity than CEST; therefore, CESL is more suitable for CE-MRI of intermediate exchange protons.

  19. Are basophil histamine release and high affinity IgE receptor expression involved in asymptomatic skin sensitization?

    DEFF Research Database (Denmark)

    Jensen, Bettina Margrethe; Assing, K; Jensen, Lone Hummelshøj

    2006-01-01

    . However, a relationship between the AS status and FcepsilonRI has not been investigated. We aimed to characterize basophils from AS by looking at histamine release (HR) (sensitivity and reactivity) and the FcepsilonRI molecule, and compare it with nonatopic (NA) or allergic (A) persons....

  20. Phylogenetic signal in phenotypic traits related to carbon source assimilation and chemical sensitivity in Acinetobacter species.

    Science.gov (United States)

    Van Assche, Ado; Álvarez-Pérez, Sergio; de Breij, Anna; De Brabanter, Joseph; Willems, Kris A; Dijkshoorn, Lenie; Lievens, Bart

    2017-01-01

    A common belief is that the phylogeny of bacteria may reflect molecular functions and phenotypic characteristics, pointing towards phylogenetic conservatism of traits. Here, we tested this hypothesis for a large set of Acinetobacter strains. Members of the genus Acinetobacter are widespread in nature, demonstrate a high metabolic diversity and are resistant to several environmental stressors. Notably, some species are known to cause opportunistic human infections. A total of 133 strains belonging to 33 species with validly published names, two genomic species and species of an as-yet unknown taxonomic status were analyzed using the GENIII technology of Biolog, which allows high-throughput phenotyping. We estimated the strength and significance of the phylogenetic signal of each trait across phylogenetic reconstructions based on partial RNA polymerase subunit B (rpoB) and core genome sequences. Secondly, we tested whether phylogenetic distance was a good predictor of trait differentiation by Mantel test analysis. And finally, evolutionary model fitting was used to determine if the data for each phenotypic character was consistent with a phylogenetic or an essentially random model of trait distribution. Our data revealed that some key phenotypic traits related to substrate assimilation and chemical sensitivity are linked to the phylogenetic placement of Acinetobacter species. The strongest phylogenetic signals found were for utilization of different carbon sources such as some organic acids, amino acids and sugars, thus suggesting that in the diversification of Acinetobacter carbon source assimilation has had a relevant role. Future work should be aimed to clarify how such traits have shaped the remarkable ability of this bacterial group to dominate in a wide variety of habitats.

  1. Sensitivity of polar stratospheric ozone loss to uncertainties in chemical reaction kinetics

    Directory of Open Access Journals (Sweden)

    S. R. Kawa

    2009-06-01

    Full Text Available The impact and significance of uncertainties in model calculations of stratospheric ozone loss resulting from known uncertainty in chemical kinetics parameters is evaluated in trajectory chemistry simulations for the Antarctic and Arctic polar vortices. The uncertainty in modeled ozone loss is derived from Monte Carlo scenario simulations varying the kinetic (reaction and photolysis rate parameters within their estimated uncertainty bounds. Simulations of a typical winter/spring Antarctic vortex scenario and Match scenarios in the Arctic produce large uncertainty in ozone loss rates and integrated seasonal loss. The simulations clearly indicate that the dominant source of model uncertainty in polar ozone loss is uncertainty in the Cl2O2 photolysis reaction, which arises from uncertainty in laboratory-measured molecular cross sections at atmospherically important wavelengths. This estimated uncertainty in JCl2O2 from laboratory measurements seriously hinders our ability to model polar ozone loss within useful quantitative error limits. Atmospheric observations, however, suggest that the Cl2O2 photolysis uncertainty may be less than that derived from the lab data. Comparisons to Match, South Pole ozonesonde, and Aura Microwave Limb Sounder (MLS data all show that the nominal recommended rate simulations agree with data within uncertainties when the Cl2O2 photolysis error is reduced by a factor of two, in line with previous in situ ClOx measurements. Comparisons to simulations using recent cross sections from Pope et al. (2007 are outside the constrained error bounds in each case. Other reactions producing significant sensitivity in polar ozone loss include BrO+ClO and its branching ratios. These uncertainties challenge our confidence in modeling polar ozone depletion and projecting future changes in response to changing halogen

  2. Sensitivity of polar stratospheric ozone loss to uncertainties in chemical reaction kinetics

    Directory of Open Access Journals (Sweden)

    M. L. Santee

    2009-11-01

    Full Text Available The impact and significance of uncertainties in model calculations of stratospheric ozone loss resulting from known uncertainty in chemical kinetics parameters is evaluated in trajectory chemistry simulations for the Antarctic and Arctic polar vortices. The uncertainty in modeled ozone loss is derived from Monte Carlo scenario simulations varying the kinetic (reaction and photolysis rate parameters within their estimated uncertainty bounds. Simulations of a typical winter/spring Antarctic vortex scenario and Match scenarios in the Arctic produce large uncertainty in ozone loss rates and integrated seasonal loss. The simulations clearly indicate that the dominant source of model uncertainty in polar ozone loss is uncertainty in the Cl2O2 photolysis reaction, which arises from uncertainty in laboratory-measured molecular cross sections at atmospherically important wavelengths. This estimated uncertainty in JCl2O2 from laboratory measurements seriously hinders our ability to model polar ozone loss within useful quantitative error limits. Atmospheric observations, however, suggest that the Cl2O2 photolysis uncertainty may be less than that derived from the lab data. Comparisons to Match, South Pole ozonesonde, and Aura Microwave Limb Sounder (MLS data all show that the nominal recommended rate simulations agree with data within uncertainties when the Cl2O2 photolysis error is reduced by a factor of two, in line with previous in situ ClOx measurements. Comparisons to simulations using recent cross sections from Pope et al. (2007 are outside the constrained error bounds in each case. Other reactions producing significant sensitivity in polar ozone loss include BrO + ClO and its branching ratios. These uncertainties challenge our confidence in modeling polar ozone depletion and projecting future changes in response to changing halogen

  3. International ring trial of the epidermal equivalent sensitizer potency assay: reproducibility and predictive-capacity

    NARCIS (Netherlands)

    Teunis, M.A.T.; Spiekstra, S.W.; Smits, M.; Adriaens, E.; Eltze, T.; Galbiati, V.; Krul, C.A.M.; Landsiedel, R.; Pieters, R.; Reinders, J.; Roggen, E.; Corsini, E.; Gibbs, S.

    2014-01-01

    This study describes the international ring trial of the epidermal-equivalent (EE) sensitizer potency assay. This assay does not distinguish a sensitizer from a non-sensitizer, but may classify known skin sensitizers according to their potency. It assesses the chemical concentration resulting in 50%

  4. International ring trial of the epidermal equivalent sensitizer potency assay: reproducibility and predictive capacity

    NARCIS (Netherlands)

    Teunis, M.A.T.; Spiekstra, S.W.; Smits, M.; Adriaens, E.; Eltze, T.; Galbiati, V.; Krul, C.; Landsiedel, R.; Pieters, R.; Reinders, J.; Roggen, E.; Corsini, E.; Gibbs, S.

    2014-01-01

    This study describes the international ring trial of the epidermal-equivalent (EE) sensitizer potency assay. This assay does not distinguish a sensitizer from a non-sensitizer, but may classify known skin sensitizers according to their potency. It assesses the chemical concentration resulting in 50%

  5. Sensitization according to skin prick testings in atopic patients with asthma or rhinitis at 24 allergy clinics in Northern Europe and Asia

    Directory of Open Access Journals (Sweden)

    Nils E Eriksson

    1998-01-01

    Full Text Available Skin prick tests (SPT were performed on 2113 atopic patients (407 children and 1 706 adults with asthma and/or rhinitis at 24 allergy clinics in Iceland, Norway, Denmark, Sweden, Estonia, Lithuania and Russia. Test extracts were Dermatophagoides pteronyssinus (D. pteronyssinus, Dermatophagoides farinae [D. farinae, cat, dog, horse, birch, timothy, mugwort, Cladosporium, Alternaria, cockroach, chironomids (red mosquito larvae, RML and shrimp. Among the allergens, timothy followed by cat, birch and dog gave the highest number of positive SPT. Positive SPT with house dust mites (HDM, furred animals, RML and Cladosporium were more common in asthmatics than in patients with rhinitis; birch and timothy more common in patients with rhinitis. Sensitization against D. pteronyssinus, horse, timothy and Cladosporium was more common in men than in women. Although the general sensitization pattern of the atopic patients at the participating centers showed similarities, there were also significant differences between centers. Positive SPT with furred animals were most prevalent in Northern and Central Sweden and St Petersburg, and least common in Siberia and Denmark. Pollen allergy was most common in Novosibirsk and on the west coast of Sweden, and less common in Vladivostok. Sensitization against HDM was most common in Lithuania and least prevalent in Northern Sweden and Finland. Insect allergens gave the most positive reactions in St Petersburg and the least positive reaction in Novosibirsk. Sensitization against multiple allergens was found in 74% of the patients and a mono-allergy in 26%. The degree of atopy was higher in males than in females and higher in asthmatics than in patients with rhinitis. The month of birth of the patients did not influence significantly the test results. It is concluded that although the sensitization pattern shows similarities in different regions, it is also influenced to some extent by residence as well as by diagnosis, sex

  6. Estimation of mean-glandular dose from monitoring breast entrance skin air kerma using a high sensitivity metal oxide semiconductor field effect transistor (MOSFET) dosimeter system in mammography.

    Science.gov (United States)

    Dong, S L; Chu, T C; Lee, J S; Lan, G Y; Wu, T H; Yeh, Y H; Hwang, J J

    2002-12-01

    Estimation of mean-glandular dose (MGD) has been investigated in recent years due to the potential risks of radiation-induced carcinogenesis associated with the mammographic examination for diagnostic radiology. In this study, a new technique for immediate readout of breast entrance skin air kerma (BESAK) using high sensitivity MOSFET dosimeter after mammographic projection was introduced and a formula for the prediction of tube output with exposure records was developed. A series of appropriate conversion factors was applied to the MGD determination from the BESAK. The study results showed that signal response of the high sensitivity MOSFET exhibited excellent linearity within mammographic dose ranges, and that the energy dependence was less than 3% for each anode/filter combination at the tube potentials 25-30 kV. Good agreement was observed between the BESAK and the tube exposure output measurement for breasts thicker than 30 mm. In addition, the air kerma estimated from our prediction formula provided sufficient accuracy for thinner breasts. The average MGD from 120 Asian females was 1.5 mGy, comparable to other studies. Our results suggest that the high sensitivity MOSFET dosimeter system is a good candidate for immediately readout of BESAK after mammographic procedures.

  7. Acute sensitivity of a broad range of freshwater mussels to chemicals with different modes of toxic action.

    Science.gov (United States)

    Wang, Ning; Ivey, Christopher D; Ingersoll, Christopher G; Brumbaugh, William G; Alvarez, David; Hammer, Edward J; Bauer, Candice R; Augspurger, Tom; Raimondo, Sandy; Barnhart, M Christopher

    2017-03-01

    Freshwater mussels, one of the most imperiled groups of animals in the world, are generally underrepresented in toxicity databases used for the development of ambient water quality criteria and other environmental guidance values. Acute 96-h toxicity tests were conducted to evaluate the sensitivity of 5 species of juvenile mussels from 2 families and 4 tribes to 10 chemicals (ammonia, metals, major ions, and organic compounds) and to screen 10 additional chemicals (mainly organic compounds) with a commonly tested mussel species, fatmucket (Lampsilis siliquoidea). In the multi-species study, median effect concentrations (EC50s) among the 5 species differed by a factor of ≤2 for chloride, potassium, sulfate, and zinc; a factor of ≤5 for ammonia, chromium, copper, and nickel; and factors of 6 and 12 for metolachlor and alachlor, respectively, indicating that mussels representing different families or tribes had similar sensitivity to most of the tested chemicals, regardless of modes of action. There was a strong linear relationship between EC50s for fatmucket and the other 4 mussel species across the 10 chemicals (r(2)  = 0.97, slope close to 1.0), indicating that fatmucket was similar to other mussel species; thus, this commonly tested species can be a good surrogate for protecting other mussels in acute exposures. The sensitivity of juvenile fatmucket among different populations or cultured from larvae of wild adults and captive-cultured adults was also similar in acute exposures to copper or chloride, indicating captive-cultured adult mussels can reliably be used to reproduce juveniles for toxicity testing. In compiled databases for all freshwater species, 1 or more mussel species were among the 4 most sensitive species for alachlor, ammonia, chloride, potassium, sulfate, copper, nickel, and zinc; therefore, the development of water quality criteria and other environmental guidance values for these chemicals should reflect the sensitivity of mussels. In

  8. Acute sensitivity of a broad range of freshwater mussels to chemicals with different modes of toxic action

    Science.gov (United States)

    Wang, Ning; Ivey, Chris D.; Ingersoll, Christopher G.; Brumbaugh, William G.; Alvarez, David; Hammer, Edward J.; Bauer, Candice R.; Augspurger, Tom; Raimondo, Sandy; Barnhart, M.Christopher

    2017-01-01

    Freshwater mussels, one of the most imperiled groups of animals in the world, are generally underrepresented in toxicity databases used for the development of ambient water quality criteria and other environmental guidance values. Acute 96-h toxicity tests were conducted to evaluate the sensitivity of 5 species of juvenile mussels from 2 families and 4 tribes to 10 chemicals (ammonia, metals, major ions, and organic compounds) and to screen 10 additional chemicals (mainly organic compounds) with a commonly tested mussel species, fatmucket (Lampsilis siliquoidea). In the multi-species study, median effect concentrations (EC50s) among the 5 species differed by a factor of ≤2 for chloride, potassium, sulfate, and zinc; a factor of ≤5 for ammonia, chromium, copper, and nickel; and factors of 6 and 12 for metolachlor and alachlor, respectively, indicating that mussels representing different families or tribes had similar sensitivity to most of the tested chemicals, regardless of modes of action. There was a strong linear relationship between EC50s for fatmucket and the other 4 mussel species across the 10 chemicals (r2 = 0.97, slope close to 1.0), indicating that fatmucket was similar to other mussel species; thus, this commonly tested species can be a good surrogate for protecting other mussels in acute exposures. The sensitivity of juvenile fatmucket among different populations or cultured from larvae of wild adults and captive-cultured adults was also similar in acute exposures to copper or chloride, indicating captive-cultured adult mussels can reliably be used to reproduce juveniles for toxicity testing. In compiled databases for all freshwater species, 1 or more mussel species were among the 4 most sensitive species for alachlor, ammonia, chloride, potassium, sulfate, copper, nickel, and zinc; therefore, the development of water quality criteria and other environmental guidance values for these chemicals should reflect the sensitivity of mussels. In

  9. Sensitivity of chemical vapor deposition diamonds to DD and DT neutrons at OMEGA and the National Ignition Facility

    Science.gov (United States)

    Kabadi, N. V.; Sio, H.; Glebov, V.; Gatu Johnson, M.; MacPhee, A.; Frenje, J. A.; Li, C. K.; Seguin, F.; Petrasso, R.; Forrest, C.; Knauer, J.; Rinderknecht, H. G.

    2016-11-01

    The particle-time-of-flight (pTOF) detector at the National Ignition Facility (NIF) is used routinely to measure nuclear bang-times in inertial confinement fusion implosions. The active detector medium in pTOF is a chemical vapor deposition diamond. Calibration of the detectors sensitivity to neutrons and protons would allow measurement of nuclear bang times and hot spot areal density (ρR) on a single diagnostic. This study utilizes data collected at both NIF and Omega in an attempt to determine pTOF's absolute sensitivity to neutrons. At Omega pTOF's sensitivity to DT-n is found to be stable to within 8% at different bias voltages. At the NIF pTOF's sensitivity to DD-n varies by up to 59%. This variability must be decreased substantially for pTOF to function as a neutron yield detector at the NIF. Some possible causes of this variability are ruled out.

  10. Comparison of the sensitivities of common in vitro and in vivo assays of estrogenic activity: application of chemical toxicity distributions.

    Science.gov (United States)

    Dobbins, Laura L; Brain, Richard A; Brooks, Bryan W

    2008-12-01

    A number of contaminants in municipal effluent discharges are estrogen agonists to fish. Whereas several in vitro and in vivo techniques have been developed to assess the estrogenic activity of these compounds or ambient environmental samples, previous comparisons of the relative sensitivities of these approaches remain inconclusive. We employed a probabilistic hazard assessment approach using chemical toxicity distributions (CTDs) to perform a novel evaluation of relative sensitivities of six common in vitro and in vivo assays. We predicted that there was an 8.3% (human breast ademocarcinoma cell line, MCF-7, assay), 6.3% (yeast estrogen screen assay), or 1.9% (fish hepatocyte vitellogenin, VTG, assay) probability of detecting a compound in aquatic systems that will elicit an estrogenic response at concentrations at or below 0.1 microg/L, suggesting that the MCF-7 assay was the most sensitive in vitro assay evaluated in this study. The probabilities of eliciting the estrogenic response of VTG induction at a concentration less than 0.1 microg/L in rainbow trout, fathead minnow, and Japanese medaka were determined at 29.9, 26.2, and 18.8%, respectively. Thus, rainbow trout VTG induction was the most sensitive in vivo assay assessed. Subsequently, CTDs may provide a useful technique for hazard assessment of chemical classes for which exposure data are limited and for chemicals with common toxicological mechanisms and modes of action.

  11. Your Skin

    Science.gov (United States)

    ... Room? What Happens in the Operating Room? Your Skin KidsHealth > For Kids > Your Skin Print A A ... are really dead skin cells. continue Bye-Bye Skin Cells These old cells are tough and strong, ...

  12. Estimation of the relative sensitivity of the comparative tuberculin skin test in tuberculous cattle herds subjected to depopulation.

    Directory of Open Access Journals (Sweden)

    Katerina Karolemeas

    Full Text Available Bovine tuberculosis (bTB is one of the most serious economic animal health problems affecting the cattle industry in Great Britain (GB, with incidence in cattle herds increasing since the mid-1980s. The single intradermal comparative cervical tuberculin (SICCT test is the primary screening test in the bTB surveillance and control programme in GB and Ireland. The sensitivity (ability to detect infected cattle of this test is central to the efficacy of the current testing regime, but most previous studies that have estimated test sensitivity (relative to the number of slaughtered cattle with visible lesions [VL] and/or positive culture results lacked post-mortem data for SICCT test-negative cattle. The slaughter of entire herds ("whole herd slaughters" or "depopulations" that are infected by bTB are occasionally conducted in GB as a last-resort control measure to resolve intractable bTB herd breakdowns. These provide additional post-mortem data for SICCT test-negative cattle, allowing a rare opportunity to calculate the animal-level sensitivity of the test relative to the total number of SICCT test-positive and negative VL animals identified post-mortem (rSe. In this study, data were analysed from 16 whole herd slaughters (748 SICCT test-positive and 1031 SICCT test-negative cattle conducted in GB between 1988 and 2010, using a bayesian hierarchical model. The overall rSe estimate of the SICCT test at the severe interpretation was 85% (95% credible interval [CI]: 78-91%, and at standard interpretation was 81% (95% CI: 70-89%. These estimates are more robust than those previously reported in GB due to inclusion of post-mortem data from SICCT test-negative cattle.

  13. Comparison of tropical and temperate freshwater animal species' acute sensitivities to chemicals: implications for deriving safe extrapolation factors.

    Science.gov (United States)

    Kwok, Kevin W H; Leung, Kenneth M Y; Lui, Gilbert S G; Chu, S Vincent K H; Lam, Paul K S; Morritt, David; Maltby, Lorraine; Brock, Theo C M; Van den Brink, Paul J; Warne, Michael St J; Crane, Mark

    2007-01-01

    Toxicity data for tropical species are often lacking for ecological risk assessment. Consequently, tropical and subtropical countries use water quality criteria (WQC) derived from temperate species (e.g., United States, Canada, or Europe) to assess ecological risks in their aquatic systems, leaving an unknown margin of uncertainty. To address this issue, we use species sensitivity distributions of freshwater animal species to determine whether temperate datasets are adequately protective of tropical species assemblages for 18 chemical substances. The results indicate that the relative sensitivities of tropical and temperate species are noticeably different for some of these chemicals. For most metals, temperate species tend to be more sensitive than their tropical counterparts. However, for un-ionized ammonia, phenol, and some pesticides (e.g., chlorpyrifos), tropical species are probably more sensitive. On the basis of the results from objective comparisons of the ratio between temperate and tropical hazardous concentration values for 10% of species, or the 90% protection level, we recommend that an extrapolation factor of 10 should be applied when such surrogate temperate WQCs are used for tropical or subtropical regions and a priori knowledge on the sensitivity of tropical species is very limited or not available.

  14. Physico-chemical characterisation of lipids from Mytilus galloprovincialis (L.) and Rapana venosa and their healing properties on skin burns.

    Science.gov (United States)

    Badiu, Diana L; Balu, Alina M; Barbes, Lucica; Luque, Rafael; Nita, Roxana; Radu, Marius; Tanase, Ecaterina; Rosoiu, Natalia

    2008-09-01

    Black Sea molluscs and gastropods are the most studied organisms from the Romanian littoral zone. In particular, those from the Mytilidae species are of great interest because biochemical investigations have shown that they can be sources of biological active substances which can have different applications (e.g. food additives). We report here the extraction of lipids from two different species of molluscs (Mytilus galloprovincialis L., Mediterranean mussel) and gastropods (Rapana venosa, hard-shell clam). The extracts were evaluated in terms of antioxidant and composition properties and their healing properties were tested on skin burns in Wistar rats. Our studies proved that the two lipid extracts contained a relatively complex distribution of compounds, in terms of characteristic indices, polyunsaturated fatty acids (PUFA) and vitamins E and D. The presence of such compounds rendered the extracts very efficient in healing induced skin burns in Wistar rats. The histological analysis showed a reduction in the time of healing (12-13 and 13-15 days for the Mytilus galloprovincialis (L.) Rapana venosa extracts, respectively) compared to 20-22 for untreated animals, based on results from tissues and blood samples. Our investigations have been proved to be promising in terms of future potential applications of the extracts as skin-care products, cosmetics and/or pharmaceutical preparations owing to their dermorestitutive properties.

  15. Skin sensitizers in cosmetics and beyond: potential multiple mechanisms of action and importance of T-cell assays for in vitro screening.

    Science.gov (United States)

    Vukmanović, Stanislav; Sadrieh, Nakissa

    2017-03-22

    Allergic contact dermatitis (ACD) is a delayed-type hypersensitivity (DTH) reaction induced by repeated contact with sensitizers. The ability of a chemical to act as a sensitizer has most frequently been tested in animals. As the use of animals for these purposes is gradually and globally being phased out, there is a need for reliable in vitro surrogate assays. Currently proposed in vitro assays are designed to test four key events of the adverse outcome pathway (AOP) involving covalent modification of self-proteins by sensitizers (haptenation) and presentation of new antigens (hapten/carrier complexes) to the immune system. There appears to be imperfect alignment of in vitro assays with clinical and/or animal data, suggesting possibly additional mechanisms of ACD development. Indeed, studies on allergies to small drugs, small chemical-induced HLA-peptide exchange for vaccination purposes and cosmetic ingredient-induced exposure of autoantigens suggest a possibility of DTH response promotion by hapten/carrier-independent mechanisms. Therefore, there is a need for additional appropriate in vitro assays, in order to achieve maximal concordance between clinical and/or animal data and in vitro assays. In this paper, we will review evidence supporting the idea of diverse mechanisms of ACD development. We will also discuss the impact of these multiple mechanisms, on the AOP and on the in vitro assays that should be used for allergen detection. We will propose alloreactivity-like reactions, aided by computer modeling and biochemical tests of compound-HLA binding, as additional tools for better prediction of DTH reactions, resulting from exposure to ingredients in cosmetic products. The combination of the proposed tests, along with the existing assays, should further enhance animal-free assessment of sensitizing potential of individual chemicals.

  16. Global sensitivity analysis of the GEOS-Chem chemical transport model: ozone and hydrogen oxides during ARCTAS (2008)

    Science.gov (United States)

    Christian, Kenneth E.; Brune, William H.; Mao, Jingqiu

    2017-03-01

    Developing predictive capability for future atmospheric oxidation capacity requires a detailed analysis of model uncertainties and sensitivity of the modeled oxidation capacity to model input variables. Using oxidant mixing ratios modeled by the GEOS-Chem chemical transport model and measured on the NASA DC-8 aircraft, uncertainty and global sensitivity analyses were performed on the GEOS-Chem chemical transport model for the modeled oxidants hydroxyl (OH), hydroperoxyl (HO2), and ozone (O3). The sensitivity of modeled OH, HO2, and ozone to model inputs perturbed simultaneously within their respective uncertainties were found for the flight tracks of NASA's Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) A and B campaigns (2008) in the North American Arctic. For the spring deployment (ARCTAS-A), ozone was most sensitive to the photolysis rate of NO2, the NO2 + OH reaction rate, and various emissions, including methyl bromoform (CHBr3). OH and HO2 were overwhelmingly sensitive to aerosol particle uptake of HO2 with this one factor contributing upwards of 75 % of the uncertainty in HO2. For the summer deployment (ARCTAS-B), ozone was most sensitive to emission factors, such as soil NOx and isoprene. OH and HO2 were most sensitive to biomass emissions and aerosol particle uptake of HO2. With modeled HO2 showing a factor of 2 underestimation compared to measurements in the lowest 2 km of the troposphere, lower uptake rates (γHO2 < 0. 055), regardless of whether or not the product of the uptake is H2O or H2O2, produced better agreement between modeled and measured HO2.

  17. Sensitization to cereals and peanut evidenced by skin prick test and specific IgE in food-tolerant, grass pollen allergic patients

    Directory of Open Access Journals (Sweden)

    Martens Maria

    2011-12-01

    Full Text Available Abstract Background The botanical relation between grass and cereal grains may be relevant when diagnosing food allergy to cereals. The aim was to investigate the diagnostic specificity of skin prick test (SPT and specific immunoglobulin E (sIgE tests to cereals and peanut in grass pollen allergic subjects without history of, and clinically reactions to foods botanically related to grass. Methods 70 subjects (41 females; mean age 32 years and 20 healthy controls (13 females; mean age 24 years were tested by open food challenge (OFC with cereals and peanut. SPT and sIgE both with Immulite® (Siemens and ImmunoCAP® (Phadia to grass and birch pollen, cereals, peanut and bromelain were performed. Results Of the 65 OFC-negative subjects 29-46% (SPT, depending on cut-off, 20% (Immulite and 38% (ImmunoCAP had positive results to one or more of the foods tested. Controls were negative in all tests. Cross-reactive carbohydrate determinants (CCD as evidenced by reaction to bromelain could explain only a minority of the measured IgE-sensitizations. Conclusion Grass pollen allergic patients with documented food tolerance to cereals and peanut may express significant sensitization. False-positive cereal or peanut allergy diagnoses may be a quantitatively important problem both in routine clinical work and epidemiological studies.

  18. Skin tribology: Science friction?

    NARCIS (Netherlands)

    Heide, van der E.; Zeng, X.; Masen, M.A.

    2013-01-01

    The application of tribological knowledge is not just restricted to optimizing mechanical and chemical engineering problems. In fact, effective solutions to friction and wear related questions can be found in our everyday life. An important part is related to skin tribology, as the human skin is fre

  19. A versatile chemical conversion synthesis of Cu2S nanotubes and the photovoltaic activities for dye-sensitized solar cell.

    Science.gov (United States)

    Shuai, Xuemin; Shen, Wenzhong; Hou, Zhaoyang; Ke, Sanmin; Xu, Chunlong; Jiang, Cheng

    2014-01-01

    A versatile, low-temperature, and low-cost chemical conversion synthesis has been developed to prepare copper sulfide (Cu2S) nanotubes. The successful chemical conversion from ZnS nanotubes to Cu2S ones profits by the large difference in solubility between ZnS and Cu2S. The morphology, structure, and composition of the yielded products have been examined by field-emission scanning electron microscopy, transmission electron microscopy, and X-ray diffraction measurements. We have further successfully employed the obtained Cu2S nanotubes as counter electrodes in dye-sensitized solar cells. The light-to-electricity conversion results show that the Cu2S nanostructures exhibit high photovoltaic conversion efficiency due to the increased surface area and the good electrocatalytical activity of Cu2S. The present chemical route provides a simple way to synthesize Cu2S nanotubes with a high surface area for nanodevice applications.

  20. Aging changes in skin

    Science.gov (United States)

    ... Stress Other causes of skin changes: Allergies to plants and other substances Climate Clothing Exposures to industrial and household chemicals Indoor heating Sunlight can cause: Loss of elasticity (elastosis) ...

  1. New formulation of chemical peeling agent: 30% salicylic acid in polyethylene glycol. Absorption and distribution of 14C-salicylic acid in polyethylene glycol applied topically to skin of hairless mice.

    Science.gov (United States)

    Ueda, Setsuko; Mitsugi, Koichi; Ichige, Kazumi; Yoshida, Kenji; Sakuma, Tomoko; Ninomiya, Shin-ichi; Sudou, Tetsuji

    2002-04-01

    Salicylic acid is used in chemical peeling procedures. However, they have caused many side effects, even salicylism. To achieve a salicylic acid peeling that would be safer for topical use, we recently developed a new formulation consisting of 30% salicylic acid in polyethylene glycol (PEG) vehicle. In an extension of our previous research, we studied the absorption of 30% salicylic acid labeled with 14C in PEG vehicle applied topically to the intact and damaged skin of male hairless mice. An ointment containing 3 mg salicylic acid in 10 mg vehicle was applied to both groups. In animals with intact skin, 1 h after application the plasma concentration of radioactivity was 1665.1 ng eq/ml, significantly lower than the 21437.6 ng eq/ml observed in mice with damaged skin. Microautoradiograms of intact skin showed that the level of radioactivity in the cornified cell layer was similar at 6 h after application. However, in damaged skin, the overall level of radioactivity showed a decrease by 3 h after application. In the carcasses remaining after the treated intact and damaged skin had been removed, 0.09 and 11.38% of the applied radioactivity remained, respectively. These findings confirm that 30% salicylic acid in PEG vehicle is little absorbed through the intact skin of hairless mice, and suggest that salicylism related to absorption through the skin of quantities of topically applied salicylic acid is not likely to occur in humans with intact skin during chemical peeling with this preparation. This new preparation of 30% salicylic acid in PEG vehicle is believed to be safe for application as a chemical peeling agent.

  2. Research on the Interaction of Hydrogen-Bond Acidic Polymer Sensitive Sensor Materials with Chemical Warfare Agents Simulants by Inverse Gas Chromatography

    OpenAIRE

    Liu Yang; Qiang Han; Shuya Cao; Feng Huang; Molin Qin; Chenghai Guo; Mingyu Ding

    2015-01-01

    Hydrogen-bond acidic polymers are important high affinity materials sensitive to organophosphates in the chemical warfare agent sensor detection process. Interactions between the sensor sensitive materials and chemical warfare agent simulants were studied by inverse gas chromatography. Hydrogen bonded acidic polymers, i.e., BSP3, were prepared for micro-packed columns to examine the interaction. DMMP (a nerve gas simulant) and 2-CEES (a blister agent simulant) were used as probes. Chemical an...

  3. High sensitivity stand-off detection and quantification of chemical mixtures using an active coherent laser spectrometer (ACLaS)

    Science.gov (United States)

    MacLeod, Neil A.; Weidmann, Damien

    2016-05-01

    High sensitivity detection, identification and quantification of chemicals in a stand-off configuration is a highly sought after capability across the security and defense sector. Specific applications include assessing the presence of explosive related materials, poisonous or toxic chemical agents, and narcotics. Real world field deployment of an operational stand-off system is challenging due to stringent requirements: high detection sensitivity, stand-off ranges from centimeters to hundreds of meters, eye-safe invisible light, near real-time response and a wide chemical versatility encompassing both vapor and condensed phase chemicals. Additionally, field deployment requires a compact, rugged, power efficient, and cost-effective design. To address these demanding requirements, we have developed the concept of Active Coherent Laser Spectrometer (ACLaS), which can be also described as a middle infrared hyperspectral coherent lidar. Combined with robust spectral unmixing algorithms, inherited from retrievals of information from high-resolution spectral data generated by satellitebased spectrometers, ACLaS has been demonstrated to fulfil the above-mentioned needs. ACLaS prototypes have been so far developed using quantum cascade lasers (QCL) and interband cascade lasers (ICL) to exploit the fast frequency tuning capability of these solid state sources. Using distributed feedback (DFB) QCL, demonstration and performance analysis were carried out on narrow-band absorbing chemicals (N2O, H2O, H2O2, CH4, C2H2 and C2H6) at stand-off distances up to 50 m using realistic non cooperative targets such as wood, painted metal, and bricks. Using more widely tunable external cavity QCL, ACLaS has also been demonstrated on broadband absorbing chemicals (dichloroethane, HFC134a, ethylene glycol dinitrate and 4-nitroacetanilide solid) and on complex samples mixing narrow-band and broadband absorbers together in a realistic atmospheric background.

  4. Dataset for human sensitivity to chemicals during development of motor function

    OpenAIRE

    Ingber, Susan Z.; Pohl, Hana R.

    2016-01-01

    The authors reviewed human data related to motor development following exposure to a subset of chemicals thoroughly reviewed in Agency for Toxic Substances and Disease Registry (ATSDR) Toxicological Profiles and Addenda. The resulting dataset includes the following variables and confounders: chemical name, exposure route, exposure duration and frequency, study design, cohort name and/or geographic location, sex of cohort subjects, NOAEL, and LOAEL. This data summary can help validate motor de...

  5. The association between null mutations in the filaggrin gene and contact sensitization to nickel and other chemicals in the general population

    DEFF Research Database (Denmark)

    Thyssen, J P; Johansen, J D; Linneberg, A;

    2010-01-01

    It was recently shown that filaggrin gene (FLG) null mutations are positively associated with nickel sensitization. We have hypothesized that histidine-rich filaggrin proteins in the epidermis chelate nickel ions and prevent their skin penetration and exposure to Langerhans cells. Furthermore, we...

  6. Development of an in vitro skin sensitization test using human cell lines: the human Cell Line Activation Test (h-CLAT). I. Optimization of the h-CLAT protocol.

    Science.gov (United States)

    Ashikaga, T; Yoshida, Y; Hirota, M; Yoneyama, K; Itagaki, H; Sakaguchi, H; Miyazawa, M; Ito, Y; Suzuki, H; Toyoda, H

    2006-08-01

    The aim of this study is to optimize the experimental conditions for an in vitro skin sensitization test using the human cell lines THP-1 and U-937. As regards pre-culturing time, the expression of CD86 on DNCB-treated THP-1 cells tended to be higher after 48h and 72h pre-culture compared with other time points evaluated. Next, we investigated the effect of chemical treatment time, and found that induction of CD86 expression on THP-1 cells by DNCB reached a plateau after 24h. Augmentation of CD86 expression is often observed when cells are treated with a subtoxic dose of allergens. To determine the appropriate dose of test samples, the cytotoxicity of test samples to THP-1 and U-937 cells was assessed with MTT assay, and the 50% inhibitory concentration (IC50) of each test sample was calculated. Based on the cytotoxicity assay data, four concentrations in the range between toxic and non-toxic were selected (0.1x, 0.5x, 1x and 2x IC50). Several kinds of antibodies were tested for staining THP-1 and U-937 cells treated with allergens/non-allergens (e.g., DNCB, Ni/SLS), and suitable antibodies for staining CD86 and CD54 were selected. We confirmed that the working dilutions of the selected CD86 and CD54 antibodies were appropriate for use in our method. The effect of an FcR blocking procedure was also evaluated. The mean fluorescence intensity (MFI value) was decreased by the FcR blocking procedure, which indicated that non-specific staining was blocked. Therefore, this procedure should be included in the method. Based on our findings, the protocol for this assay was optimized and the experimental conditions to be used in a future validation study were identified. We propose to call this kind of in vitro skin sensitization test h-CLAT, which is short for human Cell Line Activation Test.

  7. Papain Degrades Tight Junction Proteins of Human Keratinocytes In Vitro and Sensitizes C57BL/6 Mice via the Skin Independent of its Enzymatic Activity or TLR4 Activation.

    Science.gov (United States)

    Stremnitzer, Caroline; Manzano-Szalai, Krisztina; Willensdorfer, Anna; Starkl, Philipp; Pieper, Mario; König, Peter; Mildner, Michael; Tschachler, Erwin; Reichart, Ursula; Jensen-Jarolim, Erika

    2015-07-01

    Papain is commonly used in food, pharmaceutical, textile, and cosmetic industries and is known to induce occupational allergic asthma. We have previously shown that the papain-like cysteine protease Dermatophagoides pteronyssinus 1 from house dust mite exhibits percutaneous sensitization potential. We aimed here to investigate the potential of papain itself in epicutaneous sensitization. The effects of papain on tight junction (TJ) proteins were tested in vitro in human primary keratinocytes. Using C57BL/6 wild-type and Toll-like receptor 4 (TLR4)-deficient mice, we analyzed the sensitization potential of papain, its effects on the skin barrier, and immune cell recruitment. Our results show that papain affects the skin barrier by increasing transepidermal water loss, degrading TJ proteins and inducing vasodilation. When topically applied, papain exhibited a high epicutaneous inflammatory potential by recruiting neutrophils, mast cells, and CD3-positive cells and by induction of a TH2-biased antibody response. However, its high potency for specific sensitization via the skin was TLR4 independent and, in spite of its capacity to degrade epidermal TJ proteins, does not rely on its enzymatic function. From our data, we conclude that papain has all features to act as a strong allergen via the skin.

  8. Few Associations Found between Mold and Other Allergen Concentrations in the Home versus Skin Sensitivity from Children with Asthma after Hurricane Katrina in the Head-Off Environmental Asthma in Louisiana Study

    Directory of Open Access Journals (Sweden)

    L. F. Grimsley

    2012-01-01

    Full Text Available Mold and other allergen exposures exacerbate asthma symptoms in sensitized individuals. We evaluated allergen concentrations, skin test sensitivities, and asthma morbidity for 182 children, aged 4–12 years, with moderate to severe asthma, enrolled 18 months after Katrina, from the city of New Orleans and the surrounding parishes that were impacted by the storm, into the Head-off Environmental Asthma in Louisiana (HEAL observational study. Dust (indoor and air (indoor and outdoor samples were collected at baseline of 6 and 12 months. Dust samples were evaluated for dust mite, cockroach, mouse, and Alternaria by immunoassay. Air samples were evaluated for airborne mold spore concentrations. Overall, 89% of the children tested positive to ≥1 indoor allergen, with allergen-specific sensitivities ranging from 18% to 67%. Allergen concentration was associated with skin sensitivity for 1 of 10 environmental triggers analyzed (cat. Asthma symptom days did not differ with skin test sensitivity, and surprisingly, increased symptoms were observed in children whose baseline indoor airborne mold concentrations were below median levels. This association was not observed in follow-up assessments. The lack of relationship among allergen levels (including mold, sensitivities, and asthma symptoms points to the complexity of attempting to assess these associations during rapidly changing social and environmental conditions.

  9. Sensitivity of Satellite-Based Skin Temperature to Different Surface Emissivity and NWP Reanalysis Sources Demonstrated Using a Single-Channel, Viewing-Angle-Corrected Retrieval Algorithm

    Science.gov (United States)

    Scarino, B. R.; Minnis, P.; Yost, C. R.; Chee, T.; Palikonda, R.

    2015-12-01

    Single-channel algorithms for satellite thermal-infrared- (TIR-) derived land and sea surface skin temperature (LST and SST) are advantageous in that they can be easily applied to a variety of satellite sensors. They can also accommodate decade-spanning instrument series, particularly for periods when split-window capabilities are not available. However, the benefit of one unified retrieval methodology for all sensors comes at the cost of critical sensitivity to surface emissivity (ɛs) and atmospheric transmittance estimation. It has been demonstrated that as little as 0.01 variance in ɛs can amount to more than a 0.5-K adjustment in retrieved LST values. Atmospheric transmittance requires calculations that employ vertical profiles of temperature and humidity from numerical weather prediction (NWP) models. Selection of a given NWP model can significantly affect LST and SST agreement relative to their respective validation sources. Thus, it is necessary to understand the accuracies of the retrievals for various NWP models to ensure the best LST/SST retrievals. The sensitivities of the single-channel retrievals to surface emittance and NWP profiles are investigated using NASA Langley historic land and ocean clear-sky skin temperature (Ts) values derived from high-resolution 11-μm TIR brightness temperature measured from geostationary satellites (GEOSat) and Advanced Very High Resolution Radiometers (AVHRR). It is shown that mean GEOSat-derived, anisotropy-corrected LST can vary by up to ±0.8 K depending on whether CERES or MODIS ɛs sources are used. Furthermore, the use of either NOAA Global Forecast System (GFS) or NASA Goddard Modern-Era Retrospective Analysis for Research and Applications (MERRA) for the radiative transfer model initial atmospheric state can account for more than 0.5-K variation in mean Ts. The results are compared to measurements from the Surface Radiation Budget Network (SURFRAD), an Atmospheric Radiation Measurement (ARM) Program ground

  10. Theoretical investigation of conductivity sensitivities of SiC-based bio-chemical acoustic wave sensors

    Science.gov (United States)

    Fan, Li; Chen, Zhe; Zhang, Shu-yi; Zhang, Hui

    2014-02-01

    The phase velocities, electromechanical coupling coefficients, conductivity sensitivities, insert losses, and minimum detectable masses of Rayleigh and Lamb waves sensors based on silicon carbide (SiC) substrates are theoretically studied. The results are compared with the performances of the sensors based on conventional silicon substrates. It is found that the sensors using SiC substrates have higher electromechanical coupling coefficients and conductivity sensitivities than the conventional silicon-based sensors in virtue of piezoelectricity of the SiC. Moreover, higher phase velocities in SiC substrates can reduce the insert losses and minimum detectable masses of the sensors. In this case, in the detection of the gas with the tiny mass as the hydrogen, in which the conductivity sensitivity is more important than the mass sensitivity, the sensor based on the SiC substrate has a higher sensitivity and exhibits the potential to detect the gas with the concentration below the ppm level. According to the results, the performances of the sensors based on the Rayleigh and Lamb waves using the SiC substrates can be optimized by properly selecting piezoelectric films, structural parameters, and operating wavelengths.

  11. Analysis of the Local Lymph Node Assay (LLNA) variability for assessing the prediction of skin sensitisation potential and potency of chemicals with non-animal approaches.

    Science.gov (United States)

    Dumont, Coralie; Barroso, João; Matys, Izabela; Worth, Andrew; Casati, Silvia

    2016-08-01

    The knowledge of the biological mechanisms leading to the induction of skin sensitisation has favoured in recent years the development of alternative non-animal methods. During the formal validation process, results from the Local Lymph Node Assay (LLNA) are generally used as reference data to assess the predictive capacity of the non-animal tests. This study reports an analysis of the variability of the LLNA for a set of chemicals for which multiple studies are available and considers three hazard classification schemes: POS/NEG, GHS/CLP and ECETOC. As the type of vehicle used in a LLNA study is known to influence to some extent the results, two analyses were performed: considering the solvent used to test the chemicals and without considering the solvent. The results show that the number of discordant classifications increases when a chemical is tested in more than one solvent. Moreover, it can be concluded that study results leading to classification in the strongest classes (1A and EXT) seem to be more reliable than those in the weakest classes. This study highlights the importance of considering the variability of the reference data when evaluating non-animal tests.

  12. Dataset for human sensitivity to chemicals during development of motor function

    Directory of Open Access Journals (Sweden)

    Susan Z. Ingber

    2016-03-01

    Full Text Available The authors reviewed human data related to motor development following exposure to a subset of chemicals thoroughly reviewed in Agency for Toxic Substances and Disease Registry (ATSDR Toxicological Profiles and Addenda. The resulting dataset includes the following variables and confounders: chemical name, exposure route, exposure duration and frequency, study design, cohort name and/or geographic location, sex of cohort subjects, NOAEL, and LOAEL. This data summary can help validate motor development outcomes observed in animal exposure studies; it can also aid in determining whether these outcomes and corresponding exposure windows are relevant to humans.

  13. Skin barrier function

    DEFF Research Database (Denmark)

    2016-01-01

    Renowned experts present the latest knowledge Although a very fragile structure, the skin barrier is probably one of the most important organs of the body. Inward/out it is responsible for body integrity and outward/in for keeping microbes, chemicals, and allergens from penetrating the skin. Since...... the role of barrier integrity in atopic dermatitis and the relationship to filaggrin mutations was discovered a decade ago, research focus has been on the skin barrier, and numerous new publications have become available. This book is an interdisciplinary update offering a wide range of information...... on the subject. It covers new basic research on skin markers, including results on filaggrin and on methods for the assessment of the barrier function. Biological variation and aspects of skin barrier function restoration are discussed as well. Further sections are dedicated to clinical implications of skin...

  14. Skin Conditions

    Science.gov (United States)

    Your skin is your body's largest organ. It covers and protects your body. Your skin Holds body fluids in, preventing dehydration Keeps harmful ... it Anything that irritates, clogs, or inflames your skin can cause symptoms such as redness, swelling, burning, ...

  15. General practitioners' experiences with provision of healthcare to patients with self-reported multiple chemical sensitivity

    DEFF Research Database (Denmark)

    Skovbjerg, Sine; Johansen, Jeanne Duus; Rasmussen, Alice

    2009-01-01

    /biologic by 27.6%, and as psychological by 7.2%. Partial or complete avoidance of chemical exposures was recommended by 86.3%. Clinical guidelines, diagnostic tools, or more insight in the pathophysiology were requested by 84.5% of the GPs. CONCLUSION: Despite the lack of formal diagnostic labelling the patient...

  16. Acute sensitivity of the vernal pool fairy shrimp, Branchinecta lynchi (Anostraca; Branchinectidae), and surrogate species to 10 chemicals

    Science.gov (United States)

    Ivey, Chris D.; Besser, John M.; Ingersoll, Christopher G.; Wang, Ning; Rogers, Christopher; Raimondo, Sandy; Bauer, Candice R.; Hammer, Edward J.

    2017-01-01

    Vernal pool fairy shrimp, Branchinecta lynchi, (Branchiopoda; Anostraca) and other fairy shrimp species have been listed as threatened or endangered under the US Endangered Species Act. Because few data exist about the sensitivity of Branchinecta spp. to toxic effects of contaminants, it is difficult to determine whether they are adequately protected by water quality criteria. A series of acute (24-h) lethality/immobilization tests was conducted with 3 species of fairy shrimp (B. lynchi, Branchinecta lindahli, and Thamnocephalus platyurus) and 10 chemicals with varying modes of toxic action: ammonia, potassium, chloride, sulfate, chromium(VI), copper, nickel, zinc, alachlor, and metolachlor. The same chemicals were tested in 48-h tests with other branchiopods (the cladocerans Daphnia magna and Ceriodaphnia dubia) and an amphipod (Hyalella azteca), and in 96-h tests with snails (Physa gyrina and Lymnaea stagnalis). Median effect concentrations (EC50s) for B. lynchi were strongly correlated (r2 = 0.975) with EC50s for the commercially available fairy shrimp species T. platyurus for most chemicals tested. Comparison of EC50s for fairy shrimp and EC50s for invertebrate taxa tested concurrently and with other published toxicity data indicated that fairy shrimp were relatively sensitive to potassium and several trace metals compared with other invertebrate taxa, although cladocerans, amphipods, and mussels had similar broad toxicant sensitivity. Interspecies correlation estimation models for predicting toxicity to fairy shrimp from surrogate species indicated that models with cladocerans and freshwater mussels as surrogates produced the best predictions of the sensitivity of fairy shrimp to contaminants. The results of these studies indicate that fairy shrimp are relatively sensitive to a range of toxicants, but Endangered Species Act-listed fairy shrimp of the genus Branchinecta were not consistently more sensitive than other fairy shrimp taxa. Environ Toxicol Chem

  17. Acute sensitivity of the vernal pool fairy shrimp, Branchinecta lynchi (Anostraca; Branchinectidae), and surrogate species to 10 chemicals.

    Science.gov (United States)

    Ivey, Chris D; Besser, John M; Ingersoll, Chris G; Wang, Ning; Rogers, D Christopher; Raimondo, Sandy; Bauer, Candice R; Hammer, Edward J

    2017-03-01

    Vernal pool fairy shrimp, Branchinecta lynchi, (Branchiopoda; Anostraca) and other fairy shrimp species have been listed as threatened or endangered under the US Endangered Species Act. Because few data exist about the sensitivity of Branchinecta spp. to toxic effects of contaminants, it is difficult to determine whether they are adequately protected by water quality criteria. A series of acute (24-h) lethality/immobilization tests was conducted with 3 species of fairy shrimp (B. lynchi, Branchinecta lindahli, and Thamnocephalus platyurus) and 10 chemicals with varying modes of toxic action: ammonia, potassium, chloride, sulfate, chromium(VI), copper, nickel, zinc, alachlor, and metolachlor. The same chemicals were tested in 48-h tests with other branchiopods (the cladocerans Daphnia magna and Ceriodaphnia dubia) and an amphipod (Hyalella azteca), and in 96-h tests with snails (Physa gyrina and Lymnaea stagnalis). Median effect concentrations (EC50s) for B. lynchi were strongly correlated (r(2 ) = 0.975) with EC50s for the commercially available fairy shrimp species T. platyurus for most chemicals tested. Comparison of EC50s for fairy shrimp and EC50s for invertebrate taxa tested concurrently and with other published toxicity data indicated that fairy shrimp were relatively sensitive to potassium and several trace metals compared with other invertebrate taxa, although cladocerans, amphipods, and mussels had similar broad toxicant sensitivity. Interspecies correlation estimation models for predicting toxicity to fairy shrimp from surrogate species indicated that models with cladocerans and freshwater mussels as surrogates produced the best predictions of the sensitivity of fairy shrimp to contaminants. The results of these studies indicate that fairy shrimp are relatively sensitive to a range of toxicants, but Endangered Species Act-listed fairy shrimp of the genus Branchinecta were not consistently more sensitive than other fairy shrimp taxa. Environ Toxicol

  18. Electro chemical Aptasensor Based on Prussian Blue-Chitosan-Glutaraldehyde for the Sensitive Determination of Tetracycline

    Institute of Scientific and Technical Information of China (English)

    Guanghui Shen; Yemin Guo; Xia Sun∗; Xiangyou Wang

    2014-01-01

    In this paper, a novel and sensitive electrochemical aptasensor for detecting tetracycline (TET) with prussian blue (PB) as the label-free signal was fabricated. A PB-chitosan-glutaraldehyde (PB-CS-GA) system acting as the signal indicator was developed to improve the sensitivity of the electrochemical aptasensor. Firstly, the PB-CS-GA was fixed onto the glass carbon electrode surface. Then, colloidal gold nanoparticles (AuNPs) were droped onto the electrode to immobilize the anti-TET aptamer for preparation of the aptasensor. The stepwise assembly process of the aptasensor was characterized by cyclic voltammetry (C-V) and scanning electron microscope (SEM). The target TET captured onto the electrode induced the current response of the electrode due to the non-conducting biomoleculars. Under the optimum operating conditions, the response of differential pulse voltammetry (DPV) was used for detecting the concentration of TET. The proposed aptasensor showed a high sensitivity and a wide linear range of 10−9 ∼ 10−5 M and 10−5 ∼ 10−2 M with the correlation coefficients of 0.994 and 0.992, respectively. The detection limit was 3.2×10−10 M (RSD 4.12%). Due to its rapidity, sensitivity and low cost, the proposed aptasensor could be used as a pre-scanning method in TET determination for the analysis of livestock products.

  19. Mindfulness-based cognitive therapy (MBCT) for multiple chemical sensitivity (MCS)

    DEFF Research Database (Denmark)

    Hauge, Christian Riise; Rasmussen, Alice; Piet, Jacob;

    2015-01-01

    the effects of mindfulness-based cognitive therapy (MBCT) for individuals with MCS. METHODS: The intention-to-treat sample (ITT) included 69 individuals who had been randomized to either MBCT or treatment as usual (TAU). The primary outcome measure was the Quick Environmental Exposure and Sensitivity...... positively changes emotional and cognitive representations. Possible explanations for these results are discussed....

  20. Sensitivity analysis of large system of chemical kinetic parameters for engine combustion simulation

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, H; Sanz-Argent, J; Petitpas, G; Havstad, M; Flowers, D

    2012-04-19

    In this study, the authors applied the state-of-the art sensitivity methods to downselect system parameters from 4000+ to 8, (23000+ -> 4000+ -> 84 -> 8). This analysis procedure paves the way for future works: (1) calibrate the system response using existed experimental observations, and (2) predict future experiment results, using the calibrated system.

  1. Direct vacuum inlet system enabling highly sensitive in-situ analysis of chemical reaction products

    DEFF Research Database (Denmark)

    Trimarco, Daniel Bøndergaard; Scott, Søren Bertelsen; Pedersen, Thomas

    , a capillary maintaining a controlled flow over a pressure drop to ultra-high vacuum, and inlet and outlet channels for an inert make up gas. The use of a direct inlet enables orders of magnitude higher sensitivity than differentially pumped systems without a loss in time response for volatile products, while...

  2. Correlating chemical sensitivity and basal gene expression reveals mechanism of action | Office of Cancer Genomics

    Science.gov (United States)

    Changes in cellular gene expression in response to small-molecule or genetic perturbations have yielded signatures that can connect unknown mechanisms of action (MoA) to ones previously established. We hypothesized that differential basal gene expression could be correlated with patterns of small-molecule sensitivity across many cell lines to illuminate the actions of compounds whose MoA are unknown.

  3. A sensitive gas chromatography detector based on atmospheric pressure chemical ionization by a dielectric barrier discharge.

    Science.gov (United States)

    Kirk, Ansgar T; Last, Torben; Zimmermann, Stefan

    2017-02-03

    In this work, we present a novel concept for a gas chromatography detector utilizing an atmospheric pressure chemical ionization which is initialized by a dielectric barrier discharge. In general, such a detector can be simple and low-cost, while achieving extremely good limits of detection. However, it is non-selective apart from the use of chemical dopants. Here, a demonstrator manufactured entirely from fused silica capillaries and printed circuit boards is shown. It has a size of 75×60×25mm(3) and utilizes only 2W of power in total. Unlike other known discharge detectors, which require high-purity helium, this detector can theoretically be operated using any gas able to form stable ion species. Here, purified air is used. With this setup, limits of detection in the low parts-per-billion range have been obtained for acetone.

  4. A REVIEW ON SKIN CANCER

    OpenAIRE

    S. Ramya Silpa; Chidvila V

    2013-01-01

    Skin cancer can be of 2 types mainly. They are malignant melanoma and non-malignant melanoma. Skin cancer mainly occurs due to exposure of sunlight. Ozone depletion and chemical exposures are other factors involved in precipitating skin cancer. Mutations of p53 gene are involved in UV- induced carcinogenesis. P53 gene acts vital in development of SCC. So, prevention of skin cancer is the main criteria. Regular application of sunscreens could be one of the primary prevention. The purpose of pr...

  5. Sensitivity of chemical reaction networks: a structural approach 3. Regular multimolecular systems

    CERN Document Server

    Brehm, Bernhard

    2016-01-01

    We present a systematic mathematical analysis of the qualitative steady-state response to rate perturbations in large classes of reaction networks. This includes multimolecular reactions and allows for catalysis, enzymatic reactions, multiple reaction products, nonmonotone rate functions, and non-closed autonomous systems. Our structural sensitivity analysis is based on the stoichiometry of the reaction network, only. It does not require numerical data on reaction rates. Instead, we impose mild and generic nondegeneracy conditions of algebraic type. From the structural data, only, we derive which steady-state concentrations are sensitive to, and hence influenced by, changes of any particular reaction rate - and which are not. We also establish transitivity properties for influences involving rate perturbations. This allows us to derive an influence graph which globally summarizes the influence pattern of the given network. The influence graph allows the computational, but meaningful, automatic identification ...

  6. Non-Structural protein 1 (NS1) gene of Canine Parvovirus-2 regresses chemically induced skin tumors in Wistar rats.

    Science.gov (United States)

    Santra, Lakshman; Rajmani, R S; Kumar, G V P P S Ravi; Saxena, Shikha; Dhara, Sujoy K; Kumar, Amit; Sahoo, Aditya Prasad; Singh, Lakshya Veer; Desai, G S; Chaturvedi, Uttara; Kumar, Sudesh; Tiwari, Ashok K

    2014-10-01

    The Non-Structural protein 1 of Canine Parvovirus-2 (CPV2.NS1) plays a major role in viral cytotoxicity and pathogenicity. CPV2.NS1 has been proven to cause apoptosis in HeLa cells in vitro in our laboratory. Here we report that CPV2.NS1 has no toxic side effects on healthy cells but regresses skin tumors in Wistar rats. Histopathological examination of tumor tissue from CPV2.NS1 treated group revealed infiltration of mononuclear and polymorphonuclear cells with increased extra cellular matrix, indicating signs of regression. Tumor regression was also evidenced by significant decrease in mitotic index, AgNOR count and PCNA index, and increase in TUNEL positive apoptotic cells in CPV2.NS1 treated group. Further, CPV2.NS1 induced anti-tumor immune response through significant increase in CD8(+) and NK cell population in CPV2.NS1 treated group. These findings suggest that CPV2.NS1 can be a possible therapeutic candidate as an alternative to chemotherapy for the treatment of cancer.

  7. Bitter-sensitive gustatory receptor neuron responds to chemically diverse insect repellents in the common malaria mosquito Anopheles quadrimaculatus

    Science.gov (United States)

    Sparks, Jackson T.; Dickens, Joseph C.

    2016-06-01

    Female mosquitoes feed on blood from animal hosts to obtain nutritional resources used for egg production. These contacts facilitate the spread of harmful human diseases. Chemical repellents are used to disrupt mosquito host-seeking and blood-feeding behaviors; however, little is known about the gustatory sensitivity of mosquitoes to known repellents. Here, we recorded electrical responses from gustatory receptor neurons (GRNs) housed within the labellar sensilla of female Anopheles quadrimaculatus to N,N-diethyl-3-methylbenzamide (DEET), picaridin, IR3535, 2-undecanone, p-menthane-3,8-diol, geraniol, trans-2-hexen-1-ol, quinine, and quinidine. A bitter-sensitive GRN responded to all tested repellents and quinine, a known feeding deterrent. Responses of the bitter-sensitive neuron to quinine and an isomer, quinidine, did not differ. Delayed bursts of electrical activity were observed in response to continuous stimulation with synthetic repellents at high concentrations. Electrophysiological recordings from bitter-sensitive GRNs associated with mosquito gustatory sensilla represent a convenient model to evaluate candidate repellents.

  8. Impact of self-reported multiple chemical sensitivity on everyday life: a qualitative study

    DEFF Research Database (Denmark)

    Skovbjerg, Sine; Brorson, Stig; Rasmussen, Alice;

    2009-01-01

    on everyday life are limited. OBJECTIVE: To describe the impact of MCS on everyday life, strategies for managing the condition, and experiences with healthcare management. METHODS: A focus group study was conducted, including two interviews with a sample of six women and six men between 27 and 78 years of age......, a duration of MCS of at least 1 year, and with different occupational conditions. RESULTS: MCS may severely influence different aspects of everyday life, including lifestyle, social relations, and occupational conditions. Avoiding common airborne chemicals was the most prevalent coping strategy, which...

  9. A finite difference method for estimating second order parameter sensitivities of discrete stochastic chemical reaction networks.

    Science.gov (United States)

    Wolf, Elizabeth Skubak; Anderson, David F

    2012-12-14

    We present an efficient finite difference method for the approximation of second derivatives, with respect to system parameters, of expectations for a class of discrete stochastic chemical reaction networks. The method uses a coupling of the perturbed processes that yields a much lower variance than existing methods, thereby drastically lowering the computational complexity required to solve a given problem. Further, the method is simple to implement and will also prove useful in any setting in which continuous time Markov chains are used to model dynamics, such as population processes. We expect the new method to be useful in the context of optimization algorithms that require knowledge of the Hessian.

  10. Sensitivity of biomarkers to changes in chemical emissions in the Earth’s Proterozoic atmosphere

    OpenAIRE

    2010-01-01

    The search for life beyond the Solar System is a major activity in exoplanet science. However, even if an Earth-like planet were to be found, it is unlikely to be at a similar stage of evolution as the modern Earth. It is therefore of interest to investigate the sensitivity of biomarker signals for life as we know it for an Earth-like planet but at earlier stages of evolution. Here, we assess biomarkers i.e. species almost exclusively associated with life, in present-day and in 10% present at...

  11. Preparation and Properties of Hydroxyethyl Methacrylate Chemically Modified Temperature-Sensitive Microgels

    Institute of Scientific and Technical Information of China (English)

    马晓梅; 席靖宇; 赵喜安; 唐小真

    2004-01-01

    A novel series of poly(N-isopropylacrylamide-co-hydroxyethyl methacrylate) (p(NIPAM-co-HEMA)) microgels were prepared through precipitation polymerization. Nuclear magnetic resonance (NMR), transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV) and dynamic light scattering (DLS) were employed to characterize the microgels. The experimental results indicate that the prepared microgels with narrow distribution remain good temperature sensitivity after incorporation of functional -OH groups. In marked contrast to the general rule, incorporation of hydrophilic HEMA makes the volume-phase-transition temperature shift to the lower temperature due to the strong intermolecular H-bonding between amide and -OH groups, -OH and -OH groups.

  12. A chemical method for fast and sensitive detection of DNA synthesis in vivo

    OpenAIRE

    Salic, Adrian; Mitchison, Timothy J.

    2008-01-01

    We have developed a method to detect DNA synthesis in proliferating cells, based on the incorporation of 5-ethynyl-2′-deoxyuridine (EdU) and its subsequent detection by a fluorescent azide through a Cu(I)-catalyzed [3 + 2] cycloaddition reaction (“click” chemistry). Detection of the EdU label is highly sensitive and can be accomplished in minutes. The small size of the fluorescent azides used for detection results in a high degree of specimen penetration, allowing the staining of whole-mount ...

  13. Skin Infections

    Science.gov (United States)

    ... Old Feeding Your 8- to 12-Month-Old Feeding Your 1- to 2-Year-Old First Aid: Skin ... (bacterial infection of the deeper layers of the skin and tissues beneath) are typical childhood skin infections. The usual bacterial culprits in skin ...

  14. Sensitive monitoring of volatile chemical warfare agents in air by atmospheric pressure chemical ionization mass spectrometry with counter-flow introduction.

    Science.gov (United States)

    Seto, Yasuo; Kanamori-Kataoka, Mieko; Tsuge, Koichiro; Ohsawa, Isaac; Iura, Kazumitsu; Itoi, Teruo; Sekiguchi, Hiroyuki; Matsushita, Koji; Yamashiro, Shigeharu; Sano, Yasuhiro; Sekiguchi, Hiroshi; Maruko, Hisashi; Takayama, Yasuo; Sekioka, Ryoji; Okumura, Akihiko; Takada, Yasuaki; Nagano, Hisashi; Waki, Izumi; Ezawa, Naoya; Tanimoto, Hiroyuki; Honjo, Shigeru; Fukano, Masumi; Okada, Hidehiro

    2013-03-05

    A new method for sensitively and selectively detecting chemical warfare agents (CWAs) in air was developed using counter-flow introduction atmospheric pressure chemical ionization mass spectrometry (MS). Four volatile and highly toxic CWAs were examined, including the nerve gases sarin and tabun, and the blister agents mustard gas (HD) and Lewisite 1 (L1). Soft ionization was performed using corona discharge to form reactant ions, and the ions were sent in the direction opposite to the airflow by an electric field to eliminate the interfering neutral molecules such as ozone and nitrogen oxide. This resulted in efficient ionization of the target CWAs, especially in the negative ionization mode. Quadrupole MS (QMS) and ion trap tandem MS (ITMS) instruments were developed and investigated, which were movable on the building floor. For sarin, tabun, and HD, the protonated molecular ions and their fragment ions were observed in the positive ion mode. For L1, the chloride adduct ions of L1 hydrolysis products were observed in negative ion mode. The limit of detection (LOD) values in real-time or for a 1 s measurement monitoring the characteristic ions were between 1 and 8 μg/m(3) in QMS instrument. Collision-induced fragmentation patterns for the CWAs were observed in an ITMS instrument, and optimized combinations of the parent and daughter ion pairs were selected to achieve real-time detection with LOD values of around 1 μg/m(3). This is a first demonstration of sensitive and specific real-time detection of both positively and negatively ionizable CWAs by MS instruments used for field monitoring.

  15. Skin absorption through atopic dermatitis skin

    DEFF Research Database (Denmark)

    Halling-Overgaard, A-S; Kezic, S; Jakasa, I

    2017-01-01

    Patients with atopic dermatitis have skin barrier impairment in both lesional and non-lesional skin. They are typically exposed to emollients daily and topical anti-inflammatory medicaments intermittently, hereby increasing the risk of developing contact allergy and systemic exposed to chemicals...... ingredients found in these topical preparations. We systematically searched for studies that investigated skin absorption of various penetrants, including medicaments, in atopic dermatitis patients, but also animals with experimentally induced dermatitis. We identified 40 articles, i.e. 11 human studies...... examining model penetrants, 26 human studies examining atopic dermatitis drugs and 3 animal studies. We conclude that atopic dermatitis patients have nearly two-fold increased skin absorption when compared to healthy controls. There is a need for well-designed epidemiological and dermato...

  16. Skin Biomes.

    Science.gov (United States)

    Fyhrquist, N; Salava, A; Auvinen, P; Lauerma, A

    2016-05-01

    The cutaneous microbiome has been investigated broadly in recent years and some traditional perspectives are beginning to change. A diverse microbiome exists on human skin and has a potential to influence pathogenic microbes and modulate the course of skin disorders, e.g. atopic dermatitis. In addition to the known dysfunctions in barrier function of the skin and immunologic disturbances, evidence is rising that frequent skin disorders, e.g. atopic dermatitis, might be connected to a dysbiosis of the microbial community and changes in the skin microbiome. As a future perspective, examining the skin microbiome could be seen as a potential new diagnostic and therapeutic target in inflammatory skin disorders.

  17. Sensitivity of the deep-sea amphipod Eurythenes gryllus to chemically dispersed oil.

    Science.gov (United States)

    Olsen, Gro Harlaug; Coquillé, Nathalie; Le Floch, Stephane; Geraudie, Perrine; Dussauze, Matthieu; Lemaire, Philippe; Camus, Lionel

    2016-04-01

    In the context of an oil spill accident and the following oil spill response, much attention is given to the use of dispersants. Dispersants are used to disperse an oil slick from the sea surface into the water column generating a cloud of dispersed oil droplets. The main consequence is an increasing of the sea water-oil interface which induces an increase of the oil biodegradation. Hence, the use of dispersants can be effective in preventing oiling of sensitive coastal environments. Also, in case of an oil blowout from the seabed, subsea injection of dispersants may offer some benefits compared to containment and recovery of the oil or in situ burning operation at the sea surface. However, biological effects of dispersed oil are poorly understood for deep-sea species. Most effects studies on dispersed oil and also other oil-related compounds have been focusing on more shallow water species. This is the first approach to assess the sensitivity of a macro-benthic deep-sea organism to dispersed oil. This paper describes a toxicity test which was performed on the macro-benthic deep-sea amphipod (Eurythenes gryllus) to determine the concentration causing lethality to 50% of test individuals (LC50) after an exposure to dispersed Brut Arabian Light (BAL) oil. The LC50 (24 h) was 101 and 24 mg L(-1) after 72 h and 12 mg L(-1) at 96 h. Based on EPA scale of toxicity categories to aquatic organisms, an LC50 (96 h) of 12 mg L(-1) indicates that the dispersed oil was slightly to moderately toxic to E. gryllus. As an attempt to compare our results to others, a literature study was performed. Due to limited amount of data available for dispersed oil and amphipods, information on other crustacean species and other oil-related compounds was also collected. Only one study on dispersed oil and amphipods was found, the LC50 value in this study was similar to the LC50 value of E. gryllus in our study. Since toxicity data are important input to risk assessment and net environmental

  18. Gene expression profiling in persons with multiple chemical sensitivity before and after a controlled n-butanol exposure session

    Science.gov (United States)

    Dantoft, Thomas M; Skovbjerg, Sine; Andersson, Linus; Claeson, Anna-Sara; Engkilde, Kaare; Lind, Nina; Nordin, Steven; Hellgren, Lars I

    2017-01-01

    Objectives To investigate the pathophysiological pathways leading to symptoms elicitation in multiple chemical sensitivity (MCS) by comparing gene expression in MCS participants and healthy controls before and after a chemical exposure optimised to cause symptoms among MCS participants. The first hypothesis was that unexposed and symptom-free MCS participants have similar gene expression patterns to controls and a second hypothesis that MCS participants can be separated from controls based on differential gene expression upon a controlled n-butanol exposure. Design Participants were exposed to 3.7 ppm n-butanol while seated in a windowed exposure chamber for 60 min. A total of 26 genes involved in biochemical pathways found in the literature have been proposed to play a role in the pathogenesis of MCS and other functional somatic syndromes were selected. Expression levels were compared between MCS and controls before, within 15 min after being exposed to and 4 hours after the exposure. Settings Participants suffering from MCS and healthy controls were recruited through advertisement at public places and in a local newspaper. Participants 36 participants who considered themselves sensitive were prescreened for eligibility. 18 sensitive persons fulfilling the criteria for MCS were enrolled together with 18 healthy controls. Outcome measures 17 genes showed sufficient transcriptional level for analysis. Group comparisons were conducted for each gene at the 3 times points and for the computed area under the curve (AUC) expression levels. Results MCS participants and controls displayed similar gene expression levels both at baseline and after the exposure and the computed AUC values were likewise comparable between the 2 groups. The intragroup variation in expression levels among MCS participants was noticeably greater than the controls. Conclusions MCS participants and controls have similar gene expression levels at baseline and it was not possible to separate

  19. Sensitivity ofBeauveria bassiana to solanine and tomatine : Plant defensive chemicals inhibit an insect pathogen.

    Science.gov (United States)

    Costa, S D; Gaugler, R R

    1989-02-01

    The alkaloids solanine and tomatine and the polyene antibiotic nystatin were tested in vitro against the entomopathogenic fungusBeauveria bassiana. Nystatin was the most inhibitory compound tested, reducing colony formation, growth, and development of conidiaphores to a greater degree and at lower concentrations than the alkaloids. Tomatine inhibited colony formation and growth more than solanine, which had relatively little effect on the fungus. The toxicity of tomatine suggests that germination of conidia and subsequent hyphal growth would be inhibited when an insect consumes conidia along with foliage containing 0.100 mg/g (fresh weight) of this compound. The sensitivity ofB. bassiana to alkaloids appears to be in the middle of the range found with other fungi.

  20. A chemical method for fast and sensitive detection of DNA synthesis in vivo.

    Science.gov (United States)

    Salic, Adrian; Mitchison, Timothy J

    2008-02-19

    We have developed a method to detect DNA synthesis in proliferating cells, based on the incorporation of 5-ethynyl-2'-deoxyuridine (EdU) and its subsequent detection by a fluorescent azide through a Cu(I)-catalyzed [3 + 2] cycloaddition reaction ("click" chemistry). Detection of the EdU label is highly sensitive and can be accomplished in minutes. The small size of the fluorescent azides used for detection results in a high degree of specimen penetration, allowing the staining of whole-mount preparations of large tissue and organ explants. In contrast to BrdU, the method does not require sample fixation or DNA denaturation and permits good structural preservation. We demonstrate the use of the method in cultured cells and in the intestine and brain of whole animals.

  1. Nerve Growth Factor Inhibits Gd3+-sensitive Calcium Influx and Reduces Chemical Anoxic Neuronal Death

    Institute of Scientific and Technical Information of China (English)

    Hui JIANG; Shunlian TIAN; Yan ZENG; Jing SHI

    2008-01-01

    To investigate whether glutamate and voltage-gated calcium channels-independent calcium influx exists during acute anoxic neuronal damage and its possible relationship to neuronal protective function of NGF. In in vitro model of acute anoxia, hippocampal cultures from newborn rats were exposed to 3 mmol/L KCN. Changes of intracellular Ca2+ concentration ([Ca2+]i) were monitored by con-focal imaging and cell viability was assayed by PI and cFDA staining. The results showed that after treatment with primary hippocampal cultures with 3 mmol/L KCN for 15 min,[Ca2+]i was significantly increased 6.27-fold compared to pre-anoxia level and 73.3% of the cells died.When combination of 20 μmol/L MK-801 (glutamate receptor antagonist), 40 μmol/L CNQX (AMPA receptor antagonist) and 5 μmol/L nimodipine (voltage-gated calcium channel antagonist) (hereafter denoted as MCN) were administrated to hippocampal cultures, levels of [Ca2+]i and cell death rate induced by KCN were partially reduced by 35.9% and 47.5% respectively. However, Gd3+ (10μmol/L) almost completely blocked KCN-mediated [Ca2+]i elevation by 81.9% and reduced neuronal death by 88.8% in the presence of MCN. It is noteworthy that NGF, used in combination with MCN,inhibited KCN-induced [Ca2+]i increase by 77.4% and reduced cell death by 87.1%. Only PLC inhibitor U73122 (10 μmol/L) abolished NGF effects. It is concluded that Gd3+-sensitive calcium influx,which is NMDA (glutamate receptor) and voltage-gated calcium channels-independent, is responsible for acute anoxic neuronal death. NGF can inhibit Gd3+-sensitive calcium influx and reduce anoxic neuronal death through activating PLC pathway.

  2. Photovoltaic conversion in TiO{sub 2} coatings sensitized with chemical deposited CdSe thin films

    Energy Technology Data Exchange (ETDEWEB)

    Rincon, M. E; Orihuela, A; Vazquez, G [Centro de Investigacion en Energia, UNAM, Temixco, Morelos (Mexico)

    2000-07-01

    We have investigated the photovoltaic conversion of spray painted titanium dioxide coatings sensitized with chemically deposited cadmium selenide thin films. The optical and photoelectrochemical characterization of the composite films indicate the importance of thermal treatments in improving the annealed cadmium selenide films, the sensitized films based on spray-painted TiO{sub 2} show stronger photocurrents and have a red shifted spectral response. This behavior, along with is good photostability, might broaden the field of applications of the sensitized films, which can be used the trigger water oxidation and reduction reactions in photocatalytic waste treatment. [Spanish] Hemos investigado la conversion fotovoltaica de recubrimientos aplicados por dispersion de dioxido de titanio sensibilizado con peliculas delgadas de selenurio de cadmio depositado quimicamente. La caracterizacion optica y fotoquimica de las peliculas compuestas indican la importancia de tratamientos termicos para mejorar las peliculas de seleniuro de calcio destemplado, las peliculas sensibilizadas basadas en la pintura aplicada con dispersores de TiO{sub 2} muestran fotocorrientes mas elevadas y tienen una respuesta espectral desplazada hacia el rojo. Este comportamiento, juntamente con una buena fotoestabilidad puede ampliar el campo de aplicaciones de peliculas sensibilizadas que pueden usarse para disparar las reacciones de oxidacion y reduccion en el tratamiento del tratamiento fotocatalitico de desperdicio.

  3. Chemical crosslinking of acrylic acid to form biocompatible pH sensitive hydrogel reinforced with cellulose nanocrystals (CNC)

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Lim Sze; Ahmad, Ishak; Lazim, Mohd Azwani Shah Mat [Faculty of Science and Technology, University Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor (Malaysia); Amin, Mohd. Cairul Iqbal Mohd [Faculty of Pharmacy, University Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur (Malaysia)

    2014-09-03

    The purpose of this study is to produce a novel pH and temperature sensitive hydrogel, composed of poly(acrylic acid) (PAA) and cellulose nanocrystal (CNC). CNC was extracted from kenaf fiber through a series of alkali and bleaching treatments followed by acid hydrolysis. The PAA was then subjected to chemical cross-linking using the cross-linking agent (N,N-methylenebisacrylamide) with CNC entrapped in PAA matrix. The mixture was casted onto petri dish to obtain disc shape hydrogel. The effects of reaction conditions such as the ratio of PAA and CNC on the swelling behavior of the hydrogel obtained towards pH and temperature were studied. The obtained hydrogel was further subjected to different tests such swelling test for swelling behaviour at different pH and temperature along with scanning electron microscopy (SEM) for morphology analysis. The hydrogel obtained showed excellent pH sensitivity and obtained maximum swelling at pH 7. Besides that, hydrogel obtained showed significant increase in swelling ratio when temperature of swelling medium was increased from 25°C to 37°C. SEM micrograph showed that the pore size of the hydrogel decreases with increase of CNC content proving that the hydrogel structure became more rigid with addition of CNC. The PAA/CNC hydrogel with such excellent sensitivity towards pH and temperature can be developed further as drug carrier.

  4. A cross-sectional study of self-reported chemical-related sensitivity is associated with gene variants of drug-metabolizing enzymes

    Directory of Open Access Journals (Sweden)

    Fabig Nathalie

    2007-02-01

    Full Text Available Abstract Background N-acetyltransferases (NAT and glutathione S-transferases (GST are involved in the metabolism of several ubiquitous chemical substances leading to the activation and detoxification of carcinogenic heterocyclic and aromatic amines. Since polymorphisms within these genes are described to influence the metabolism of ubiquitous chemicals, we conducted the present study to determine if individuals with self-reported chemical-related sensitivity differed from controls without self-reported chemical-related sensitivity with regard to the distribution of genotype frequencies of NAT2, GSTM1, GSTT1, and GSTP1 polymorphisms. Methods Out of 800 subjects who answered a questionnaire of ten items with regard to their severity of chemical sensitivity 521 unrelated individuals agreed to participate in the study. Subsequently, genetic variants of the NAT2, GSTM1, GSTT1, and GSTP1 genes were analyzed. Results The results show significant differences between individuals with and without self-reported chemical-related sensitivity with regard to the distribution of NAT2, GSTM1, and GSTT1 gene variants. Cases with self-reported chemical-related sensitivity were significantly more frequently NAT2 slow acetylators (controlled OR = 1.81, 95% CI = 1.27–2.59, P = 0.001. GSTM1 and GSTT1 genes were significantly more often homozygously deleted in those individuals reporting sensitivity to chemicals compared to controls (GSTM1: controlled OR 2.08, 95% CI = 1.46–2.96, P = 0.0001; GSTT1: controlled OR = 2.80, 95% CI = 1.65–4.75, P = 0.0001. Effects for GSTP1 gene variants were observed in conjunction with GSTM1, GSTT1 and NAT2 gene. Conclusion The results from our study population show that individuals being slow acetylators and/or harbouring a homozygous GSTM1 and/or GSTT1 deletion reported chemical-related hypersensitivity more frequently.

  5. CHARACTERIZATION OF XANTHOMONAS AXONOPODIS PV. PUNICAE ISOLATES FROM WESTERN MAHARASHTRA AND THEIR SENSITIVITY TO CHEMICAL TREATMENTS

    Directory of Open Access Journals (Sweden)

    K. S. RAGHUWANSHI

    2013-01-01

    Full Text Available Bacterial blight of pomegranate caused by Xanthomonas axonopodis pv. punicae is a major biotic constraint inpeninsular India. Field survey was undertaken in the major pomegranate growing regions of Western Maharashtra,which revealed the high prevalence of bacterial blight incidence in Solapur, Sangli and Nashik districts. Fourdifferent isolates of this pathogen were obtained from the highly infected plant materials collected during the fieldsurvey. X. axonopodis pv. punicae was detected from infected plant material and its identity was confirmed bymorphological, physiological, hypersensitive and pathogenicity tests. Nashik isolate was most virulent. On InterSimple Sequence Repeat (ISSR analysis they formed separate clusters with Akkalkot-Solapur isolate being mostdivergent, while Deola-Nashik and Sangamner-Ahmednagar isolates were most similar. Six chemical treatmentsshowed complete control under in vitro conditions while rest varied in their response to isolates. Completecontrol in all four isolates was observed with Bordeaux mixture (1%; captan (0.25% + Copper oxychloride(0.3%, captan (0.25% + copper hydroxide (0.3%, bromopol (500 ppm + copper oxychloride (0.3%,streptocycline (250 ppm + copper hydroxide (0.3%, streptocycline (500 ppm + copper hydroxide (0.3%during in vitro study

  6. Sensitivity of Biomarkers to Changes in Chemical Emissions in the Earth's Proterozoic Atmosphere

    CERN Document Server

    Grenfell, John Lee; von Paris, Philip; Godolt, Mareike; Hedelt, Pascal; Patzer, Beate; Stracke, Barbara; Rauer, Heike

    2010-01-01

    The search for life beyond the Solar System is a major activity in exoplanet science. However, even if an Earth-like planet were to be found, it is unlikely to be at a similar stage of evolution as the modern Earth. It is therefore of interest to investigate the sensitivity of biomarker signals for life as we know it for an Earth-like planet but at earlier stages of evolution. Here, we assess biomarkers i.e. species almost exclusively associated with life, in present-day and in 10% present atmospheric level oxygen atmospheres corresponding to the Earth's Proterozoic period. We investigate the impact of proposed enhanced microbial emissions of the biomarker nitrous oxide, which photolyses to form nitrogen oxides which can destroy the biomarker ozone. A major result of our work is regardless of the microbial activity producing nitrous oxide in the early anoxic ocean, a certain minimum ozone column can be expected to persist in Proterozoic-type atmospheres due to a stabilising feedback loop between ozone, nitrou...

  7. Quantum chemical investigations aimed at modeling highly efficient zinc porphyrin dye sensitized solar cells.

    Science.gov (United States)

    Irfan, Ahmad; Hina, Naz; Al-Sehemi, Abdullah G; Asiri, Abdullah M

    2012-09-01

    Zinc tetraphenylporphyrin (ZnTPP) was modified by a push-pull strategy and then density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were performed for the resulting derivatives. The smallest HOMO-LUMO energy gaps were found in ZnTPP-6 and ZnTPP-7, which had nitro substituents and a conjugated chain, while the largest was observed for ZnTPP-5. The energy gaps of all of the systems designed in this work were smaller than that of ZnTPP. Clear intramolecular charge transfer was observed from donor to acceptor in ZnTPP-6 and ZnTPP-7, which had nitro groups at positions R8, R9, and R10, as well as in ZnTPP-3 and ZnTPP-4, which had cyano groups at those positions. The narrow band gaps (compared to that of ZnTPP) of these designed systems, where the LUMO is above the conduction band of TiO(2) and the HOMO is below the redox couple, indicate that they are efficient sensitizers. The B bands of these newly designed derivatives, except for ZnTPP-5, are redshifted compared with the B band of ZnTPP.

  8. Research on the Interaction of Hydrogen-Bond Acidic Polymer Sensitive Sensor Materials with Chemical Warfare Agents Simulants by Inverse Gas Chromatography

    Directory of Open Access Journals (Sweden)

    Liu Yang

    2015-06-01

    Full Text Available Hydrogen-bond acidic polymers are important high affinity materials sensitive to organophosphates in the chemical warfare agent sensor detection process. Interactions between the sensor sensitive materials and chemical warfare agent simulants were studied by inverse gas chromatography. Hydrogen bonded acidic polymers, i.e., BSP3, were prepared for micro-packed columns to examine the interaction. DMMP (a nerve gas simulant and 2-CEES (a blister agent simulant were used as probes. Chemical and physical parameters such as heats of absorption and Henry constants of the polymers to DMMP and 2-CEES were determined by inverse gas chromatography. Details concerning absorption performance are also discussed in this paper.

  9. Research on the interaction of hydrogen-bond acidic polymer sensitive sensor materials with chemical warfare agents simulants by inverse gas chromatography.

    Science.gov (United States)

    Yang, Liu; Han, Qiang; Cao, Shuya; Huang, Feng; Qin, Molin; Guo, Chenghai; Ding, Mingyu

    2015-06-02

    Hydrogen-bond acidic polymers are important high affinity materials sensitive to organophosphates in the chemical warfare agent sensor detection process. Interactions between the sensor sensitive materials and chemical warfare agent simulants were studied by inverse gas chromatography. Hydrogen bonded acidic polymers, i.e., BSP3, were prepared for micro-packed columns to examine the interaction. DMMP (a nerve gas simulant) and 2-CEES (a blister agent simulant) were used as probes. Chemical and physical parameters such as heats of absorption and Henry constants of the polymers to DMMP and 2-CEES were determined by inverse gas chromatography. Details concerning absorption performance are also discussed in this paper.

  10. Sensitivity of biomarkers to changes in chemical emissions in the Earth’s Proterozoic atmosphere

    Science.gov (United States)

    Grenfell, J. L.; Gebauer, S.; von Paris, P.; Godolt, M.; Hedelt, P.; Patzer, A. B. C.; Stracke, B.; Rauer, H.

    2011-01-01

    The search for life beyond the Solar System is a major activity in exoplanet science. However, even if an Earth-like planet were to be found, it is unlikely to be at a similar stage of evolution as the modern Earth. It is therefore of interest to investigate the sensitivity of biomarker signals for life as we know it for an Earth-like planet but at earlier stages of evolution. Here, we assess biomarkers, i.e. species almost exclusively associated with life, in present-day and in 10% present atmospheric level oxygen atmospheres corresponding to the Earth's Proterozoic period. We investigate the impact of proposed enhanced microbial emissions of the biomarker nitrous oxide, which photolyses to form nitrogen oxides which can destroy the biomarker ozone. A major result of our work is regardless of the microbial activity producing nitrous oxide in the early anoxic ocean, a certain minimum ozone column can be expected to persist in Proterozoic-type atmospheres due to a stabilising feedback loop between ozone, nitrous oxide and the ultraviolet radiation field. Atmospheric nitrous oxide columns were enhanced by a factor of 51 for the Proterozoic "Canfield ocean" scenario with 100 times increased nitrous oxide surface emissions. In such a scenario nitrous oxide displays prominent spectral features, so may be more important as a biomarker than previously considered in such cases. The run with "Canfield ocean" nitrous oxide emissions enhanced by a factor of 100 also featured additional surface warming of 3.5 K. Our results suggest that the Proterozoic ozone layer mostly survives the changes in composition which implies that it is indeed a good atmospheric biomarker.

  11. Thermodynamic Insights and Conceptual Design of Skin-Sensitive Chitosan Coated Ceramide/PLGA Nanodrug for Regeneration of Stratum Corneum on Atopic Dermatitis

    OpenAIRE

    Sang-Myung Jung; Gwang Heum Yoon; Hoo Chul Lee; Moon Hee Jung; Sun Il Yu; Seung Ju Yeon; Seul Ki Min; Yeo Seon Kwon; Jin Ha Hwang; Hwa Sung Shin

    2015-01-01

    Atopic dermatitis (AD) is a complex skin disease primarily characterized by psoriasis of the stratum corneum. AD drugs have usually been used in acidic and hydrophilic solvents to supply moisture and prevent lipid defects. Ceramide is a typical treatment agent to regenerate the stratum corneum and relieve symptoms of AD. However, ceramide has limitation on direct use for skin because of its low dispersion properties in hydrophilic phase and side effects at excessive treatment. In this study, ...

  12. Study of surfactant-skin interactions by skin impedance measurements.

    Science.gov (United States)

    Lu, Guojin; Moore, David J

    2012-02-01

    The stratum corneum (SC) plays a very critical physiological role as skin barrier in regulating water loss through the skin and protects the body from a wide range of physical and chemical exogenous insults. Surfactant-containing formulations can induce skin damage and irritation owing to surfactant absorption and penetration. It is generally accepted that reduction in skin barrier properties occurs only after surfactants have penetrated/permeated into the skin barrier. To mitigate the harshness of surfactant-based cleansing products, penetration/permeation of surfactants should be reduced. Skin impedance measurements have been taken in vitro on porcine skin using vertical Franz diffusion cells to investigate the impact of surfactants, temperature and pH on skin barrier integrity. These skin impedance results demonstrate excellent correlation with other published methods for assessing skin damage and irritation from different surfactant chemistry, concentration, pH, time of exposure and temperature. This study demonstrates that skin impedance can be utilized as a routine approach to screen surfactant-containing formulations for their propensity to compromise the skin barrier and hence likely lead to skin irritation.

  13. CHEMICALS

    CERN Multimedia

    Medical Service

    2002-01-01

    It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546

  14. Split-face comparative study of 1550 nm fractional photothermolysis and trichloroacetic acid 15% chemical peeling for facial melasma in Asian skin.

    Science.gov (United States)

    Hong, Seung-Phil; Han, Seung-Seog; Choi, Seok-Joo; Kim, Myoung-Shin; Won, Chong-Hyun; Lee, Mi-Woo; Choi, Jee-Ho; Moon, Kee-Chan; Kim, Youn Jin; Chang, Sung-Eun

    2012-04-01

    Fractional photothermolysis (FP) therapy and chemical peels have been reported to be effective in patients with recalcitrant melasma. However, there is little information to compare the efficacy of single treatment session in Asian women. The aim of this study was to examine the efficacy, long-lasting outcomes and safety of a single session of 1550-nm erbium-doped FP in Asian patients, compared with trichloroacetic acid (TCA) peel with a medium depth. Eighteen Korean women (Fitzpatrick skin type III or IV) with moderate-to-severe bilateral melasma were randomly treated with a single session of 1550-nm FP on one cheek, and with a 15% TCA peel on the other cheek. Outcome measures included an objective melasma area severity index and subjective patient-rated overall improvement at 4 and 12 weeks after treatment. Melasma lesions were significantly improved 4 weeks after either treatment, but melasma recurred at 12 weeks. Post-inflammatory hyperpigmentation developed in 28% of patients at 4 weeks but resolved in all but one patient by 12 weeks. There was no difference between FP treatment and TCA peeling with respect to any outcome measure. FP laser and TCA peel treatments were equally effective and safe when used to treat moderate-to-severe melasma, but neither treatment was long-lasting. We suggest that multiple or periodic maintenance treatments and/or supplemental procedures may be required for the successful treatment of melasma in Asian women.

  15. Chemical reconstruction of skin scars therapy using 100% trichloroacetic acid in the treatment of atrophic facial post varicella scars: A pilot study

    Directory of Open Access Journals (Sweden)

    Nidheesh Agarwal

    2013-01-01

    Full Text Available Context: Chickenpox (varicella is a common viral disease caused by Varicella zoster virus. Facial atrophic scars after varicella infection are not uncommon and pose a cosmetic problem. Like atrophic scars of other aetiologies, they are a difficult condition to treat. There are not enough references in the literature regarding efficient treatment of post varicella scars. High strength Trichloroacetic acid (TCA, which is known to cause dermal collagen remodelling, was used to treat varicella scars in the present study. Aims: The study was undertaken to assess the efficiency of Chemical Reconstruction of Skin Scars (CROSS technique using 100% TCA in the treatment of atrophic facial post varicella scars. Settings and Design: Open label, pilot study. Materials and Methods: A total of 16 patients with atrophic facial post varicella scars were treated by focal application of 100% TCA solution by pressing down upon the scar surface by a toothpick (CROSS technique. Total 4 sittings were given at 2 weekly intervals and the results evaluated after 3 months of follow-up. Statistical analysis was carried out using Fischer′s exact t-test. Results: All of the 13 patients who completed the study showed good clinical improvement, with 69% patients grading the response as excellent (>75% improvement, whereas the rest 31% patients reporting good (51-75% improvement. No significant complications were seen in any patient. Conclusions: CROSS technique using 100% TCA is a safe, cheap and effective therapy for the treatment of post varicella scars.

  16. Skin Cancer

    Science.gov (United States)

    ... are round and lie directly under squamous cells. Melanocytes are specialized skin cells that produce pigment called melanin. The melanin pigment produced by melanocytes gives skin its color. It also protects the ...

  17. Skin Cancer

    Science.gov (United States)

    ... the head, face, neck, hands, and arms. Another type of skin cancer, melanoma, is more dangerous but less common. Anyone ... cancer is found early. If not treated, some types of skin cancer cells can spread to other tissues and organs. ...

  18. Sagging Skin

    Science.gov (United States)

    ... Dermatologic Surgery Expertise for the life of your skin (TM) Public Resources Dermatologic Surgery Conditions Treatments and ... learn-more"> 3 million Americans are diagnosed with skin cancer every year Any suspicious new growths or ...

  19. Skin tears.

    Science.gov (United States)

    Baranoski, S

    2001-08-01

    Skin tears are a serious, painful problem for older patients. Find out how your staff can recognize patients at risk, what they can do to prevent skin tears, and how to manage them effectively if they occur.

  20. Skin turgor

    Science.gov (United States)

    ... arm or abdomen is checked. The skin is held for a few seconds then released. Skin with ... University of Washington, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the ...

  1. Quasi-solid state dye-sensitized solar cells based on pyridine or imidazole containing copolymer chemically crosslinked gel electrolytes

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Quasi-solid state dye-sensitized solar cells based on chemically crosslinking with backbone polymers of poly(vinylpyridine-co-acrylonitrile) (P(VP-co-AN)) or poly(vinylimidazole-co-acrylonitrile) (P(VIM-co- AN)) and diiodide compounds of I(CH2)6I or I(CH2CH2O)nCH2CH2I solidified EC/PC/KI/I2 gel electrolytes have been fabricated. The ionic conductivities and apparent diffusion coefficients of I3-Of the electrolytes and cell performances have been investigated. Providing chemically crosslinking points, pyridine or imidazole from the backbone polymers benefited the open circuit voltage and fill factor of the cells. Consequently, the overall energy conversion efficiencies of the quasi-solid DSSCs improved over 10% even near 20% from that of the liquid electrolyte before solidification. Besides, the employing of crosslinker I(CH2CH2O)nCH2CH2I showed higher electrolytic and cell characters than that of I(CH2)6I.

  2. Enhanced gas sensing performance of electrospun Pt-functionalized NiO nanotubes with chemical and electronic sensitization.

    Science.gov (United States)

    Fu, Jiecai; Zhao, Changhui; Zhang, Junli; Peng, Yong; Xie, Erqing

    2013-08-14

    Pt-functionalized NiO composite nanotubes were synthesized by a simple electrospinning method, and their morphology, chemistry, and crystal structure have been characterized at the nanoscale. It was found that the Pt nanoparticles were dispersed uniformly in the NiO nanotubes, and the Pt-functionalized NiO composite nanotubes showed some dendritic structure in the body of nanotubes just like thorns growing in the nanotubes. Compared with the pristine NiO nanotube based gas sensor and other NiO-based gas sensors reported previously, the Pt-functionalized NiO composite nanotube based gas sensor showed substantially enhanced electrical responses to target gas (methane, hydrogen, acetone, and ethanol), especially ethanol. The NiO-Pt 0.7% composite nanotube based gas sensor displayed a response value of 20.85 at 100 ppm at ethanol and 200 °C, whereas the pristine NiO nanotube based gas sensor only showed a response of 2.06 under the same conditions. Moreover, the Pt-functionalized NiO composite nanotube based gas sensor demonstrated outstanding gas selectivity for ethanol against methane, hydrogen, and acetone. The reason for which the Pt-functionalized NiO composite nanotube based gas sensor obviously enhanced the gas sensing performance is attributed to the role of Pt on the chemical sensitization (catalytic oxidation) of target gases and the electronic sensitization (Fermi-level shifting) of NiO.

  3. A miniature photoelectrochemical sensor based on organic electrochemical transistor for sensitive determination of chemical oxygen demand in wastewaters.

    Science.gov (United States)

    Liao, Jianjun; Lin, Shiwei; Zeng, Min; Yang, Yue

    2016-05-01

    A three-electrode configuration is often required in the conventional photoelectrochemical measurements. Nevertheless, one common drawback is the reference electrode and the counter electrode used in the measurements, which has been proved to be an impediment for the miniaturization. In this study, a simple, cost-effective and miniature photoelectrochemical sensor based on high sensitive organic electrochemical transistor (OECT) is developed and used for the determination of chemical oxygen demand (COD) in wastewaters. The devices show detection limit down to 0.01 mg/L COD, which is two orders of magnitude better than that of the conventional photoelectrochemical method. The excellent sensing performance can be contributed to the novel sensing mechanism of OECT devices. That is, the devices are sensitive to the potential changes induced by the photoelectrochemical reaction on TiO2 nanotube arrays gate electrodes. Real sample analyses are also carried out. The results demonstrate that the measured COD values using the OECT devices and the standard dichromate methods are in a good agreement. Since the proposed sensor is constructed on a miniature transistor, it is expected that the device shows a promising application on the integrated COD monitoring platform.

  4. Array of chemically etched fused-silica emitters for improving the sensitivity and quantitation of electrospray ionization mass spectrometry.

    Science.gov (United States)

    Kelly, Ryan T; Page, Jason S; Tang, Keqi; Smith, Richard D

    2007-06-01

    An array of emitters has been developed for increasing the sensitivity of electrospray ionization mass spectrometry (ESI-MS). The linear array consists of 19 chemically etched fused-silica capillaries arranged with 500 microm (center-to-center) spacing. The multiemitter device has a low dead volume to facilitate coupling to capillary liquid chromatography (LC) separations. The high aspect ratio of the emitters enables operation at flow rates as low as 20 nL/min/emitter, effectively extending the benefits of nanoelectrospray to higher flow rate analyses. To accommodate the larger ion current produced by the emitter array, a multicapillary inlet to the mass spectrometer was also constructed. The inlet, which matched the dimensions of the emitter array, preserved ion transmission efficiency. Standard reserpine solutions of varying concentration were electrosprayed at 1 microL/min using the multiemitter/multi-inlet combination, and the results were compared to those from a standard, single-emitter configuration. A 9-fold sensitivity enhancement was observed for the multiemitter relative to the single emitter. A bovine serum albumin tryptic digest was also analyzed, and a sensitivity increase ranging from 2.4- to 12.3-fold for the detected tryptic peptides resulted; the varying response was attributed to reduced ion suppression under the nanoESI conditions afforded by the emitter array. An equimolar mixture of leucine enkephalin and maltopentaose was studied to verify that ion suppression is indeed reduced for the multiplexed ESI (multi-ESI) array relative to a single emitter over a range of flow rates.

  5. Skin Aging

    Science.gov (United States)

    Your skin changes as you age. You might notice wrinkles, age spots and dryness. Your skin also becomes thinner and loses fat, making it ... heal, too. Sunlight is a major cause of skin aging. You can protect yourself by staying out ...

  6. The implications of non-linear biological oscillations on human electrophysiology for electrohypersensitivity (EHS) and multiple chemical sensitivity (MCS).

    Science.gov (United States)

    Sage, Cindy

    2015-01-01

    maintenance; and resilience can be compromised. Electrohypersensitivity can be caused by successive assaults on human bioelectrochemical dynamics from exogenous electromagnetic fields (EMF) and RFR or a single acute exposure. Once sensitized, further exposures are widely reported to cause reactivity to lower and lower intensities of EMF/RFR, at which point thousand-fold lower levels can cause adverse health impacts to the electrosensitive person. Electrohypersensitivity (EHS) can be a precursor to, or linked with, multiple chemical sensitivity (MCS) based on reports of individuals who first develop one condition, then rapidly develop the other. Similarity of chemical biomarkers is seen in both conditions [histamines, markers of oxidative stress, auto-antibodies, heat shock protein (HSP), melatonin markers and leakage of the blood-brain barrier]. Low intensity pulsed microwave activation of voltage-gated calcium channels (VGCCs) is postulated as a mechanism of action for non-thermal health effects.

  7. 导入透明质酸猪脱细胞真皮基质的刺激性及致敏性研究%Skin irritation and sensitization of swine acellular dermal matrix treated with hyaluronic acid

    Institute of Scientific and Technical Information of China (English)

    宁少南; 赵筱卓; 王慧英; 张国安

    2012-01-01

    Objective To evaluate the skin irritation and sensitization potential of the swine acellular dermal matrix treated with hyaluronic acid (SADM-HA).Methods (1) Skin irritation test.Twelve New Zealand rabbits were divided into SADM-HA group,allogeneic skin group,and (human) xeno-skin group according to the random number table,with 4 rabbits in each group.Four test sites were designed on the back of each rabbit.Two test sites of each rabbit in the three groups were covered with SADM-HA,allogeneic skin,and xeno-skin,respectively.Another test site was covered with gauze containing 200 g/L sodium dodecyl sulfate solution as positive control.The last test site was covered with gauze containing normal saline as negative control.The primary irritation index and cumulative irritation index of each material were calculated.(2) Skin closed-patch test.Sixty guinea pigs were used.Fifty-four guinea pigs were divided into SADM-HA group,allogeneic skin group,and (human) xeno-skin group according to the random number table,with 18 guinea pigs in each group.Twelve guinea pigs in each of the three groups were correspondingly induced and stimulated by SADM-HA,allogeneic skin,and xeno-skin,with 6 guinea pigs in each group treated with ethanol-soaked gauze to serve as negative control.The remaining 6 guinea pigs were treated with gauze containing 25% α-hexylcinnamaldehyde ethanol solution as positive control.The rating scales of Magnusson and Kligman were used to grade the condition of skin after being treated with above-mentioned materials to evaluate skin sensitivity to them at post stimulation hour 24 and 48.Data were processed with the nonparametric test of independent samples.Results (1) In the skin irritation test,the primary irritation indexes of the three dressings in SADM-HA group,allogeneic skin group,and xeno-skin group were respectively-0.04,0.13,and 0.08.The cumulative irritation indexes of the three dressings in SADM-HA group,allogeneic skin group,and xeno-skin group were

  8. 高灵敏共轭聚合物化学传感器%Conjugated Polymers for Sensitive Chemical Sensors

    Institute of Scientific and Technical Information of China (English)

    朱春雷; 杨琼; 刘礼兵; 王树

    2011-01-01

    The detections of metal ion and chemical small molecule are of great importance in view of their influences on human health,environment pollution,and food safety.Thus,considerable researches have been conducted toward designing and developing highly sensitive chemical sensors.In the past few decades,due to the superior electrical properties,conjugated polymers (CPs) have aroused great attentions and numerous revolutionary advances have emerged.More recently,facilitated by their signalamplifying response to sensing events,the possibility of CPs to be used as fluorescent probes toward designing novel chemical and biological sensors have been exploited.This mini account highlights the recent progress of CPs in our group for the detection of metal ion and chemical small molecule based on fluorescence technique.Three different signal transduction mechanisms,including electron transfer,fluorescence resonance energy transfer(FRET) and analyteinduced aggregation or conformational change,are involved in this account and concretely elaborated with corresponding examples.Finally,challenges confronted by CPs and their future directions are discussed.%金属离子和化学小分子的检测在人类健康、环境污染以及食品安全等领域具有重要意义,科学工作者们已经在设计、发展高灵敏化学传感器方面进行了大量研究。在过去的几十年里,共轭聚合物由于其卓越的光电性质,引起了人们极大的关注,并取得了众多革命性科技进展。最近,利用共轭聚合物的荧光信号放大机制,人们设计、发展了一系列新型的化学和生物传感体系。共轭聚合物的信号传感机制包括电子转移,荧光共振能量转移以及共轭聚合物聚集或构象改变。本文主要介绍我们实验室在利用共轭聚合物实现金属离子和化学小分子荧光检测方面取得的进展,并对未来发展方向与面临的挑战进行了讨论。

  9. Effect of detergents on the physico-chemical properties of skin stratum corneum: A two-photon excitation fluorescence microscopy study

    DEFF Research Database (Denmark)

    Bloksgaard, Maria; Brewer, Jonathan R.; Pashkovski, Eugene;

    2014-01-01

    OBJECTIVE: Understanding the structural and dynamical features of skin is critical for advancing innovation in personal care and drug discovery. Synthetic detergent mixtures used in commercially available body wash products are thought to be less aggressive towards the skin barrier when compared...

  10. 25th anniversary article: The evolution of electronic skin (e-skin): a brief history, design considerations, and recent progress.

    Science.gov (United States)

    Hammock, Mallory L; Chortos, Alex; Tee, Benjamin C-K; Tok, Jeffrey B-H; Bao, Zhenan

    2013-11-13

    Human skin is a remarkable organ. It consists of an integrated, stretchable network of sensors that relay information about tactile and thermal stimuli to the brain, allowing us to maneuver within our environment safely and effectively. Interest in large-area networks of electronic devices inspired by human skin is motivated by the promise of creating autonomous intelligent robots and biomimetic prosthetics, among other applications. The development of electronic networks comprised of flexible, stretchable, and robust devices that are compatible with large-area implementation and integrated with multiple functionalities is a testament to the progress in developing an electronic skin (e-skin) akin to human skin. E-skins are already capable of providing augmented performance over their organic counterpart, both in superior spatial resolution and thermal sensitivity. They could be further improved through the incorporation of additional functionalities (e.g., chemical and biological sensing) and desired properties (e.g., biodegradability and self-powering). Continued rapid progress in this area is promising for the development of a fully integrated e-skin in the near future.

  11. 照相化学增感剂专利最新动态%The Latest Development of the Patents of Photographic Chemical Sensitizer

    Institute of Scientific and Technical Information of China (English)

    边国俊

    2001-01-01

    In recent ten years, a lot of patents to the new chemical sensitizer have been applied by Eastman Kodak, Fuji, Konica companies. These chemical sensitizers comprises of Ⅷ group metal complex of Periodic Table of Elements and chalcogen element compounds.%近十年来,柯达、富士和柯尼卡公司申请了大量涉及新型化学增感剂的专利。新型增感剂包括元素周期表Ⅷ族金属络合物和硫族元素的化合物。

  12. Sensitization to cereals and peanut evidenced by skin prick test and specific IgE in food-tolerant, grass pollen allergic patients

    DEFF Research Database (Denmark)

    Martens, Maria; Schnoor, Heidi J; Malling, Hans-Jørgen;

    2011-01-01

    The botanical relation between grass and cereal grains may be relevant when diagnosing food allergy to cereals. The aim was to investigate the diagnostic specificity of skin prick test (SPT) and specific immunoglobulin E (sIgE) tests to cereals and peanut in grass pollen allergic subjects without...

  13. Thermodynamic Insights and Conceptual Design of Skin-Sensitive Chitosan Coated Ceramide/PLGA Nanodrug for Regeneration of Stratum Corneum on Atopic Dermatitis.

    Science.gov (United States)

    Jung, Sang-Myung; Yoon, Gwang Heum; Lee, Hoo Chul; Jung, Moon Hee; Yu, Sun Il; Yeon, Seung Ju; Min, Seul Ki; Kwon, Yeo Seon; Hwang, Jin Ha; Shin, Hwa Sung

    2015-12-15

    Atopic dermatitis (AD) is a complex skin disease primarily characterized by psoriasis of the stratum corneum. AD drugs have usually been used in acidic and hydrophilic solvents to supply moisture and prevent lipid defects. Ceramide is a typical treatment agent to regenerate the stratum corneum and relieve symptoms of AD. However, ceramide has limitation on direct use for skin because of its low dispersion properties in hydrophilic phase and side effects at excessive treatment. In this study, ceramide imbedded PLGA nanoparticles were developed with chitosan coating (Chi-PLGA/Cer) to overcome this problem. The chitosan coating enhanced initial adherence to the skin and prevented the initial burst of ceramide, but was degraded by the weakly acidic nature of skin, resulting in controlled release of ceramide with additional driving force of the squeezed PLGA nanoparticles. Additionally, the coating kinetics of chitosan were controlled by manipulating the reaction conditions and then mathematically modeled. The Chi-PLGA/Cer was not found to be cytotoxic and ceramide release was controlled by pH, temperature, and chitosan coating. Finally, Chi-PLGA/Cer was demonstrated to be effective at stratum corneum regeneration in a rat AD model. Overall, the results presented herein indicated that Chi-PLGA/Cer is a novel nanodrug for treatment of AD.

  14. Comparison of Chemical Sensitivity of Fresh and Long-Stored Heat Resistant Neosartorya fischeri Environmental Isolates Using BIOLOG Phenotype MicroArray System.

    Directory of Open Access Journals (Sweden)

    Jacek Panek

    Full Text Available Spoilage of heat processed food and beverage by heat resistant fungi (HRF is a major problem for food industry in many countries. Neosartorya fischeri is the leading source of spoilage in thermally processed products. Its resistance to heat processing and toxigenicity makes studies about Neosartorya fischeri metabolism and chemical sensitivity essential. In this study chemical sensitivity of two environmental Neosartorya fischeri isolates were compared. One was isolated from canned apples in 1923 (DSM3700, the other from thermal processed strawberry product in 2012 (KC179765, used as long-stored and fresh isolate, respectively. The study was conducted using Biolog Phenotype MicroArray platforms of chemical sensitivity panel and traditional hole-plate method. The study allowed for obtaining data about Neosartorya fischeri growth inhibitors. The fresh isolate appeared to be much more resistant to chemical agents than the long-stored isolate. Based on phenotype microarray assay nitrogen compounds, toxic cations and membrane function compounds were the most effective in growth inhibition of N. fischeri isolates. According to the study zaragozic acid A, thallium(I acetate and sodium selenate were potent and promising N. fischeri oriented fungicides which was confirmed by both chemical sensitivity microplates panel and traditional hole-plate methods.

  15. Multiple Chemical Sensitivity

    DEFF Research Database (Denmark)

    Dantoft, Thomas Meinertz

    immunological biomarkers in MCS via three separate studies presented in manuscript IIIV. A complementary investigation of selected biomarkers associated with alternative modes of actions was likewise examined by gene expression measures, as part of manuscript IV. The study presented in Manuscript II compared......, significantly reduced levels of IL-13 in the MCS group and no group differences in the allergen specific IgE measures. The differences were independent of factors such as sex, age, Body Mass Index, asthma, smoking, depression, anxiety and allergen-specific IgE. In conclusion, the study identified a distinct...... cells in the upper airways. Manuscript IV presents an explorative study investigating the feasibility of using gene expression profiling as an analytical tool for biomarker discovery in MCS and to study the pathogenic mechanisms, based on differential gene expression regulation upon the symptom...

  16. Sample handling in surface sensitive chemical and biological sensing: a practical review of basic fluidics and analyte transport.

    Science.gov (United States)

    Orgovan, Norbert; Patko, Daniel; Hos, Csaba; Kurunczi, Sándor; Szabó, Bálint; Ramsden, Jeremy J; Horvath, Robert

    2014-09-01

    This paper gives an overview of the advantages and associated caveats of the most common sample handling methods in surface-sensitive chemical and biological sensing. We summarize the basic theoretical and practical considerations one faces when designing and assembling the fluidic part of the sensor devices. The influence of analyte size, the use of closed and flow-through cuvettes, the importance of flow rate, tubing length and diameter, bubble traps, pressure-driven pumping, cuvette dead volumes, and sample injection systems are all discussed. Typical application areas of particular arrangements are also highlighted, such as the monitoring of cellular adhesion, biomolecule adsorption-desorption and ligand-receptor affinity binding. Our work is a practical review in the sense that for every sample handling arrangement considered we present our own experimental data and critically review our experience with the given arrangement. In the experimental part we focus on sample handling in optical waveguide lightmode spectroscopy (OWLS) measurements, but the present study is equally applicable for other biosensing technologies in which an analyte in solution is captured at a surface and its presence is monitored. Explicit attention is given to features that are expected to play an increasingly decisive role in determining the reliability of (bio)chemical sensing measurements, such as analyte transport to the sensor surface; the distorting influence of dead volumes in the fluidic system; and the appropriate sample handling of cell suspensions (e.g. their quasi-simultaneous deposition). At the appropriate places, biological aspects closely related to fluidics (e.g. cellular mechanotransduction, competitive adsorption, blood flow in veins) are also discussed, particularly with regard to their models used in biosensing.

  17. Rotary Bed Reactor for Chemical-Looping Combustion with Carbon Capture. Part 2: Base Case and Sensitivity Analysis

    KAUST Repository

    Zhao, Zhenlong

    2013-01-17

    Part 1 (10.1021/ef3014103) of this series describes a new rotary reactor for gas-fueled chemical-looping combustion (CLC), in which, a solid wheel with microchannels rotates between the reducing and oxidizing streams. The oxygen carrier (OC) coated on the surfaces of the channels periodically adsorbs oxygen from air and releases it to oxidize the fuel. A one-dimensional model is also developed in part 1 (10.1021/ef3014103). This paper presents the simulation results based on the base-case design parameters. The results indicate that both the fuel conversion efficiency and the carbon separation efficiency are close to unity. Because of the relatively low reduction rate of copper oxide, fuel conversion occurs gradually from the inlet to the exit. A total of 99.9% of the fuel is converted within 75% of the channel, leading to 25% redundant length near the exit, to ensure robustness. In the air sector, the OC is rapidly regenerated while consuming a large amount of oxygen from air. Velocity fluctuations are observed during the transition between sectors because of the complete reactions of OCs. The gas temperature increases monotonically from 823 to 1315 K, which is mainly determined by the solid temperature, whose variations with time are limited within 20 K. The overall energy in the solid phase is balanced between the reaction heat release, conduction, and convective cooling. In the sensitivity analysis, important input parameters are identified and varied around their base-case values. The resulting changes in the model-predicted performance revealed that the most important parameters are the reduction kinetics, the operating pressure, and the feed stream temperatures. © 2012 American Chemical Society.

  18. Sensitivity of thermal infrared sounders to the chemical and micro-physical properties of UTLS secondary sulphate aerosols

    Science.gov (United States)

    Sellitto, P.; Legras, B.

    2015-08-01

    Monitoring upper tropospheric-lower stratospheric (UTLS) secondary sulphate aerosols and their chemical and micro-physical properties from satellite nadir observations is crucial to better understand their formation and evolution processes and then to estimate their impact to the UTLS chemistry, and on regional and global radiative balance. Here we present a study aimed at the evaluation of the sensitivity of thermal infrared (TIR) satellite nadir observations to the chemical composition and the size distribution of idealized UTLS sulphate aerosol layers. The extinction properties of sulphuric acid/water droplets, for different sulphuric acid mixing ratios and temperatures, are systematically analysed. The extinction coefficients are derived by means of a Mie code, using refractive indexes taken from the GEISA (Gestion et Étude des Informations Spectroscopiques Atmosphériques: Management and Study of Spectroscopic Information) spectroscopic database and log-normal size distributions with different effective radii and number concentrations. IASI (Infrared Atmospheric Sounding Interferometer) pseudo-observations are generated using forward radiative transfer calculations performed with the 4A (Automatized Atmospheric Absorption Atlas) radiative transfer model, to estimate the impact of the extinction of idealized aerosol layers, at typical UTLS conditions, on the brightness temperature spectra observed by this satellite instrument. We found a marked and typical spectral signature of these aerosol layers between 700 and 1200 cm-1, due to the absorption bands of the sulphate and bi-sulphate ions and the undissociated sulphuric acid, with the main absorption peaks at 1170 and 905 cm-1. The dependence of the aerosol spectral signature to the sulphuric acid mixing ratio, and effective number concentration and radius, as well as the role of interferring parameters like the ozone, sulphur dioxide, carbon dioxide and ash absorption, and temperature and water vapour profile

  19. Sensitivity of thermal infrared sounders to the chemical and micro-physical properties of UTLS secondary sulphate aerosols

    Directory of Open Access Journals (Sweden)

    P. Sellitto

    2015-08-01

    Full Text Available Monitoring upper tropospheric-lower stratospheric (UTLS secondary sulphate aerosols and their chemical and micro-physical properties from satellite nadir observations is crucial to better understand their formation and evolution processes and then to estimate their impact to the UTLS chemistry, and on regional and global radiative balance. Here we present a study aimed at the evaluation of the sensitivity of thermal infrared (TIR satellite nadir observations to the chemical composition and the size distribution of idealized UTLS sulphate aerosol layers. The extinction properties of sulphuric acid/water droplets, for different sulphuric acid mixing ratios and temperatures, are systematically analysed. The extinction coefficients are derived by means of a Mie code, using refractive indexes taken from the GEISA (Gestion et Étude des Informations Spectroscopiques Atmosphériques: Management and Study of Spectroscopic Information spectroscopic database and log-normal size distributions with different effective radii and number concentrations. IASI (Infrared Atmospheric Sounding Interferometer pseudo-observations are generated using forward radiative transfer calculations performed with the 4A (Automatized Atmospheric Absorption Atlas radiative transfer model, to estimate the impact of the extinction of idealized aerosol layers, at typical UTLS conditions, on the brightness temperature spectra observed by this satellite instrument. We found a marked and typical spectral signature of these aerosol layers between 700 and 1200 cm−1, due to the absorption bands of the sulphate and bi-sulphate ions and the undissociated sulphuric acid, with the main absorption peaks at 1170 and 905 cm−1. The dependence of the aerosol spectral signature to the sulphuric acid mixing ratio, and effective number concentration and radius, as well as the role of interferring parameters like the ozone, sulphur dioxide, carbon dioxide and ash absorption, and temperature and

  20. Mindfulness-based cognitive therapy for multiple chemical sensitivity: a study protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Hauge Christian Riise

    2012-09-01

    Full Text Available Abstract Background Multiple chemical sensitivity (MCS is a condition characterized by recurrent, self-reported symptoms from multiple organ systems, attributable to exposure to a wide range of chemically unrelated substances at low levels. The pathophysiology is unknown, and affected individuals generally favor avoidance of the symptom triggering substances as a coping strategy. The impact of MCS on daily life may thus be severe. An intervention that may effectively reduce the impact of MCS, alleviate the symptoms and the psychological distress associated with the condition is therefore highly needed. In this study we will assess the effects of a mindfulness-based cognitive (MBCT program on MCS. Methods/Design Using a randomized controlled design (RCT, we will compare MBCT with treatment as usual (TAU. The MBCT intervention will include 8 weekly 2.5 hour sessions, and 45 minutes of mindfulness home practice 6 days each week. Participants will be asked to complete questionnaires at baseline, post-treatment, and at 6 and 12 months’ follow-up. Based on sample size estimation, 82 participants will be randomized to either the MBCT intervention or to TAU. The primary outcome will be a measure of the impact of MCS on the participants’ lives. The secondary outcome measures are physical symptoms of psychological distress, perceived stress, illness perceptions, QOL, and work ability. Lastly, we will assess whether any effect of MBCT on the primary effect measure is mediated by level of mindfulness, self-compassion, perceived stress, and rumination. Discussion This trial will provide important information on the effects of MBCT on MCS. Trials registration Clinical trials identifier NCT01240395

  1. Cortical activity during olfactory stimulation in multiple chemical sensitivity: a {sup 18}F-FDG PET/CT study

    Energy Technology Data Exchange (ETDEWEB)

    Chiaravalloti, Agostino; Di Pietro, Barbara [University Tor Vergata, Department of Biomedicine and Prevention, Rome (Italy); Pagani, Marco [Institute of Cognitive Sciences and Technologies, CNR, Rome (Italy); Department of Nuclear Medicine Karolinska Hospital Stockholm, Stockholm (Sweden); Micarelli, Alessandro; Alessandrini, Marco [University Tor Vergata, Department of Medical Science and Translational Medicine, Rome (Italy); Genovesi, Giuseppe [University La Sapienza, Department of Experimental Medicine, Rome (Italy); University La Sapienza, Regional Center for Diagnosis, Treatment and Prevention of MCS, Rome (Italy); Schillaci, Orazio [University Tor Vergata, Department of Biomedicine and Prevention, Rome (Italy); IRCCS Neuromed, Pozzilli (Italy)

    2015-04-01

    To investigate the differences in brain glucose consumption during olfactory stimulation between subjects affected by multiple chemical sensitivity (MCS) and a group of healthy individuals. Two {sup 18}F-FDG PET/CT scans were performed in 26 subjects (6 men and 20 women; mean age 46.7 ± 11 years) with a clinical diagnosis of MCS and in 11 healthy controls (6 women and 5 men; mean age 45.7 ± 11 years), the first scan after a neutral olfactory stimulation (NS) and the second after a pure olfactory stimulation (OS). Differences in {sup 18}F-FDG uptake were analysed by statistical parametric mapping (SPM2). In controls OS led to an increase in glucose consumption in BA 18 and 19 and a reduction in glucose metabolism in BA 10, 11, 32 and 47. In MCS subjects, OS led to an increase in glucose consumption in BA 20, 23, 18 and 37 and a reduction in glucose metabolism in BA 8, 9 and 10. The results of our study suggest that cortical activity in subjects with MCS differs from that in healthy individuals during olfactory stimulation. (orig.)

  2. Sensitive and fast response ethanol chemical sensor based on as-grown Gd2O3 nanostructures

    Institute of Scientific and Technical Information of China (English)

    MM Abdullah; Mohammed M Rahman; Houcine Bouzid; M Faisal; Sher Bahadar Khan; SA Al-Sayari; Adel A Ismail

    2015-01-01

    Well crystalline gadolinium oxide (Gd2O3) nanostructures were grown by annealing the hydrothermally as-prepared nanostructures without using any template. Microscopic studies of Gd2O3 nanostructures were recorded along the [111] direction due to the clearly resolved interplanar distance d(222)~0.31 nm of the cubic crystal structure Gd2O3. Sensing mechanism of Gd2O3 as efficient electron mediator for the detection of ethanol was explored. As-fabricated sensor demonstrated the high-sensitivity of~0.266 µAm/M/cm2 with low detection limit (~52.2 µmol/L) and correlation coefficient (r2, 0.618). To the best of our knowledge, this was the first report for the detection of ethanol using as-grown (at 1000 ºC) Gd2O3 nanostructures by simple and reliable I-V technique and rapid assessment of the reaction kinetics (in the order of seconds). The low cost of the starting reagents and the simplicity of the synthetic route made it a promising chemical sensor for the detection of various toxic analytes, which are not en-vironmentally safe.

  3. Odor aversion of multiple chemical sensitivities: recommendation for a name change and description of successful behavioral medicine treatment.

    Science.gov (United States)

    Amundsen, M A; Hanson, N P; Bruce, B K; Lantz, T D; Schwartz, M S; Lukach, B M

    1996-08-01

    Patients with odor-triggered symptoms, meeting the case definition of multiple chemical sensitivities (MCS), continue to be seen in our institution and other health science centers [Amundsen, Mayo Clinic Dept. Intern. Med. Newslett. 9(1) (1986)]. The term MCS, unfortunately, feeds the thesis that symptoms are allergic-immune system in origin, a theory that has not withstood scientific scrutiny [American College of Physicians, Ann. Intern. Med. 111, 168-178 (1989); Terr, Ann. Intern. Med. 119, 163-164 (1993)]. It has been proposed that some of these cases may be examples of classical (Pavlovian) conditioning: many MCS patients meet diagnostic criteria for psychiatric illnesses, especially mood, anxiety, and somatoform disorders. Attention is turning to the complex relationship between olfactory stimulation, memory, and mood (psyche) in an attempt to understand why some individuals develop odor aversion symptoms and how to best manage these, frequently, severely disabled patients. Two subjects with typical odor-triggered symptoms have been treated, using behavioral medicine techniques, with marked improvement in both cases. The term "odor aversion" is proposed rather than MCS to describe patients with these symptoms.

  4. Controlling the chemical stability of a moisture-sensitive drug product through monitoring and identification of coating process microenvironment.

    Science.gov (United States)

    Kestur, Umesh; Pandey, Preetanshu; Badawy, Sherif; Lin, Judy; Desai, Divyakant

    2014-12-10

    The objective of this work was to monitor and identify the impact of coating microenvironment, as measured by PyroButtons(®) data loggers, on the chemical stability of a moisture-sensitive drug molecule brivanib alaninate (BA). BA tablets were coated at two different scales (15 and 24 in pan). PyroButtons(®) data loggers were allowed to move freely within the tablet bed to record the temperature and relative humidity conditions of the tablet bed. The tablet moisture content at the end of the coating runs, and the rate of hydrolysis of the BA tablets based on HPLC analysis was found to be a function of the coating thermodynamic microenvironment. Wetter coating conditions resulted in tablets with higher water content and showed greater degradation upon storage. The coating process which yielded acceptable stability in a 15 in coater was transferred to a 24 in coater by maintaining similar tablet-bed relative humidity and temperature conditions. This was compared to a traditional scale-up approach where the environmental equivalency factor (EEF) was matched between scales during coating. The moisture content observed across the two scales indicated that maintaining a similar tablet-bed microenvironment ensured consistent results between scales.

  5. Identification of Lilial as a fragrance sensitizer in a perfume by bioassay-guided chemical fractionation and structure-activity relationships

    DEFF Research Database (Denmark)

    Arnau, E G; Andersen, Klaus Ejner; Bruze, M

    2000-01-01

    Fragrance materials are among the most common causes of allergic contact dermatitis. The aim of this study was to identify in a perfume fragrance allergens not included in the fragrance mix, by use of bioassay-guided chemical fractionation and chemical analysis/structure-activity relationships...... test on the pre-sensitized patient. The chemical composition of the fractions giving a positive patch-test response and repeated open application test reactions was obtained by gas chromatography-mass spectrometry. From the compounds identified, those that contained a "structural alert...... mix. The combination of bioassay-guided chemical fractionation and chemical analysis/structure-activity relationships seems to be a valuable tool for the investigation of contact allergy to fragrance materials....

  6. Skin decontamination: principles and perspectives.

    Science.gov (United States)

    Chan, Heidi P; Zhai, Hongbo; Hui, Xiaoying; Maibach, Howard I

    2013-11-01

    Skin decontamination is the primary intervention needed in chemical, biological and radiological exposures, involving immediate removal of the contaminant from the skin performed in the most efficient way. The most readily available decontamination system on a practical basis is washing with soap and water or water only. Timely use of flushing with copious amounts of water may physically remove the contaminant. However, this traditional method may not be completely effective, and contaminants left on the skin after traditional washing procedures can have toxic consequences. This article focuses on the principles and practices of skin decontamination.

  7. LSENS: A General Chemical Kinetics and Sensitivity Analysis Code for homogeneous gas-phase reactions. Part 1: Theory and numerical solution procedures

    Science.gov (United States)

    Radhakrishnan, Krishnan

    1994-01-01

    LSENS, the Lewis General Chemical Kinetics and Sensitivity Analysis Code, has been developed for solving complex, homogeneous, gas-phase chemical kinetics problems and contains sensitivity analysis for a variety of problems, including nonisothermal situations. This report is part 1 of a series of three reference publications that describe LENS, provide a detailed guide to its usage, and present many example problems. Part 1 derives the governing equations and describes the numerical solution procedures for the types of problems that can be solved. The accuracy and efficiency of LSENS are examined by means of various test problems, and comparisons with other methods and codes are presented. LSENS is a flexible, convenient, accurate, and efficient solver for chemical reaction problems such as static system; steady, one-dimensional, inviscid flow; reaction behind incident shock wave, including boundary layer correction; and perfectly stirred (highly backmixed) reactor. In addition, the chemical equilibrium state can be computed for the following assigned states: temperature and pressure, enthalpy and pressure, temperature and volume, and internal energy and volume. For static problems the code computes the sensitivity coefficients of the dependent variables and their temporal derivatives with respect to the initial values of the dependent variables and/or the three rate coefficient parameters of the chemical reactions.

  8. Skin interaction with absorbent hygiene products.

    Science.gov (United States)

    Runeman, Bo

    2008-01-01

    Skin problems due to the use of absorbent hygiene products, such as diapers, incontinence pads, and feminine sanitary articles, are mostly due to climate or chafing discomfort. If these conditions are allowed to prevail, these may develop into an irritant contact dermatitis and eventually superficial skin infections. Skin humidity and aging skin are among the most significant predisposing and aggravating factors for dermatitis development. Improved product design features are believed to explain the decline in observed diaper dermatitis among infants. Where adult incontinence-related skin problems are concerned, it is very important to apply a holistic perspective to understand the influences due to the individual's incontinence level and skin condition, as well as the hygiene and skin care measures provided. Individuals with frail, sensitive skin or with skin diseases may preferably have to use high-quality products, equipped with superabsorbent polymers and water vapor-permeable back sheets, to minimize the risk of skin complications.

  9. Your Skin

    Science.gov (United States)

    ... your body. Without skin, people's muscles, bones, and organs would be hanging out all over the place. Skin holds everything together. It also: protects our bodies helps keep our bodies at just the right temperature allows us to have the sense of touch Don't Miss Your Epidermis The ...

  10. Oily skin

    Science.gov (United States)

    ... keep your skin clean using warm water and soap, or a soapless cleanser. Clean your face with astringent pads if frequent face washing causes irritation. Use only water-based or oil-free cosmetics if you have oily skin. Your ...

  11. Sensitivity of thermal infrared nadir instruments to the chemical and microphysical properties of UTLS secondary sulfate aerosols

    Science.gov (United States)

    Sellitto, P.; Legras, B.

    2016-01-01

    Monitoring upper-tropospheric-lower-stratospheric (UTLS) secondary sulfate aerosols and their chemical and microphysical properties from satellite nadir observations is crucial to better understand their formation and evolution processes and then to estimate their impact on UTLS chemistry, and on regional and global radiative balance. Here we present a study aimed at the evaluation of the sensitivity of thermal infrared (TIR) satellite nadir observations to the chemical composition and the size distribution of idealised UTLS sulfate aerosol layers. The extinction properties of sulfuric acid/water droplets, for different sulfuric acid mixing ratios and temperatures, are systematically analysed. The extinction coefficients are derived by means of a Mie code, using refractive indices taken from the GEISA (Gestion et Étude des Informations Spectroscopiques Atmosphériques: Management and Study of Spectroscopic Information) spectroscopic database and log-normal size distributions with different effective radii and number concentrations. IASI (Infrared Atmospheric Sounding Interferometer) pseudo-observations are generated using forward radiative transfer calculations performed with the 4A (Automatized Atmospheric Absorption Atlas) radiative transfer model, to estimate the impact of the extinction of idealised aerosol layers, at typical UTLS conditions, on the brightness temperature spectra observed by this satellite instrument. We found a marked and typical spectral signature of these aerosol layers between 700 and 1200 cm-1, due to the absorption bands of the sulfate and bisulfate ions and the undissociated sulfuric acid, with the main absorption peaks at 1170 and 905 cm-1. The dependence of the aerosol spectral signature to the sulfuric acid mixing ratio, and effective number concentration and radius, as well as the role of interfering parameters like the ozone, sulfur dioxide, carbon dioxide and ash absorption, and temperature and water vapour profile uncertainties

  12. Relationship between sensitizer concentration and resist performance of chemically amplified extreme ultraviolet resists in sub-10 nm half-pitch resolution region

    Science.gov (United States)

    Kozawa, Takahiro; Santillan, Julius Joseph; Itani, Toshiro

    2017-01-01

    The development of lithography processes with sub-10 nm resolution is challenging. Stochastic phenomena such as line width roughness (LWR) are significant problems. In this study, the feasibility of sub-10 nm fabrication using chemically amplified extreme ultraviolet resists with photodecomposable quenchers was investigated from the viewpoint of the suppression of LWR. The relationship between sensitizer concentration (the sum of acid generator and photodecomposable quencher concentrations) and resist performance was clarified, using the simulation based on the sensitization and reaction mechanisms of chemically amplified resists. For the total sensitizer concentration of 0.5 nm-3 and the effective reaction radius for the deprotection of 0.1 nm, the reachable half-pitch while maintaining 10% critical dimension (CD) LWR was 11 nm. The reachable half-pitch was 7 nm for 20% CD LWR. The increase in the effective reaction radius is required to realize the sub-10 nm fabrication with 10% CD LWR.

  13. Cobalt as chemical modifier to improve chromium sensitivity and minimize matrix effects in tungsten coil atomic emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Sidnei G. [Group of Applied Instrumental Analysis, Department of Chemistry, Federal University of São Carlos, P.O. Box 676, São Carlos, SP 13560-970 (Brazil); Donati, George L., E-mail: georgedonati@yahoo.com.br [Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109 (United States); Santos, Luana N. [Group of Applied Instrumental Analysis, Department of Chemistry, Federal University of São Carlos, P.O. Box 676, São Carlos, SP 13560-970 (Brazil); Jones, Bradley T. [Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109 (United States); Nóbrega, Joaquim A. [Group of Applied Instrumental Analysis, Department of Chemistry, Federal University of São Carlos, P.O. Box 676, São Carlos, SP 13560-970 (Brazil)

    2013-05-30

    Graphical abstract: -- Highlights: •Charge transfer reactions increase the population of Cr{sup +}. •Chromium ions and electrons recombine to form excited-state Cr atoms. •A 10-fold improvement in LOD is observed for Cr emission measurements. •The two-step ionization/excitation mechanism improves sensitivity and accuracy. •High concentrations of Co also minimize matrix effects. -- Abstract: Cobalt is used as chemical modifier to improve sensitivity and minimize matrix effects in Cr determinations by tungsten coil atomic emission spectrometry (WCAES). The atomizer is a tungsten filament extracted from microscope light bulbs. A solid-state power supply and a handheld CCD-based spectrometer are also used in the instrumental setup. In the presence of 1000 mg L{sup −1} Co, WCAES limit of detection for Cr (λ = 425.4 nm) is calculated as 0.070 mg L{sup −1}; a 10-fold improvement compared to determinations without Co modifier. The mechanism involved in such signal enhancement is similar to the one observed in ICP OES and ICP-MS determinations of As and Se in the presence of C. Cobalt increases the population of Cr{sup +} by charge transfer reactions. In a second step, Cr{sup +}/e{sup −} recombination takes place, which results in a larger population of excited-state Cr atoms. This alternative excitation route is energetically more efficient than heat transfer from atomizer and gas phase to analyte atoms. A linear dynamic range of 0.25–10 mg L{sup −1} and repeatability of 3.8% (RSD, n = 10) for a 2.0 mg L{sup −1} Cr solution are obtained with this strategy. The modifier high concentration also contributes to improving accuracy due to a matrix-matching effect. The method was applied to a certified reference material of Dogfish Muscle (DORM-2) and no statistically significant difference was observed between determined and certified Cr values at a 95% confidence level. Spike experiments with bottled water samples resulted in recoveries between 93% and

  14. The future of skin metagenomics.

    Science.gov (United States)

    Mathieu, Alban; Vogel, Timothy M; Simonet, Pascal

    2014-01-01

    Metagenomics, the direct exploitation of environmental microbial DNA, is complementary to traditional culture-based approaches for deciphering taxonomic and functional microbial diversity in a plethora of ecosystems, including those related to the human body such as the mouth, saliva, teeth, gut or skin. DNA extracted from human skin analyzed by sequencing the PCR-amplified rrs gene has already revealed the taxonomic diversity of microbial communities colonizing the human skin ("skin microbiome"). Each individual possesses his/her own skin microbial community structure, with marked taxonomic differences between different parts of the body and temporal evolution depending on physical and chemical conditions (sweat, washing etc.). However, technical limitations due to the low bacterial density at the surface of the human skin or contamination by human DNA still has inhibited extended use of the metagenomic approach for investigating the skin microbiome at a functional level. These difficulties have been overcome in part by the new generation of sequencing platforms that now provide sequences describing the genes and functions carried out by skin bacteria. These methodological advances should help us understand the mechanisms by which these microorganisms adapt to the specific chemical composition of each skin and thereby lead to a better understanding of bacteria/human host interdependence. This knowledge will pave the way for more systemic and individualized pharmaceutical and cosmetic applications.

  15. Studies on chemical protectors against radiation, 29; Protective effects of methanol extracts of various Chinese traditional medicines on skin injury induced by X-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Cheng-Ming; Ohta, Setsuko; Shinoda, Masato (Hoshi Coll. of Pharmacy, Tokyo (Japan))

    1990-03-01

    In order to investigate useful protective medicines for the relief of skin injury induced by irradiation, 60 methanol extracts of Chinese traditional medicines were used in the test of protective potency on skin injury. ICR male mice at 6 weeks of age were whole-body irradiated with 1100R by using a soft X-ray generator (30 kVp, 10 mA, 190 R/min). Each methanol extract of these medicines was injected intraperitoneally into mice before or after irradiation. The degrees of skin injury were determined by a score system of skin reaction within the observation period from 21st to 40th day after irradiation. Protective potency of each medicine on skin injury was calculated from the maximum mean scores of administrated group and un-administrated group. As a result of these studies, the protective potency was detected in Unsei-in, Kumibinro-to, Keisi-syakuyaku-chimo-to, Keigai-rengyo-to, Gosyuyu-to, Koso-san, Saiko-seikan-to, Syo-kankyo-to, Syo-saiko-to, Syoma-kakkon-to, Sen-kan-meimoku-to, Zokumei-to, Sokei-kakketu-to, Bokuryo-in, Mao-to and Rikkunsi-to by intraperitoneal injection before irradiation. Of these effective medicines, only Unsei-in and Mao-to are shown to have a significant protective effect by intraperitoneal injection after irradiation. (author).

  16. Graphene oxide as sensitive layer in Love-wave surface acoustic wave sensors for the detection of chemical warfare agent simulants.

    Science.gov (United States)

    Sayago, Isabel; Matatagui, Daniel; Fernández, María Jesús; Fontecha, José Luis; Jurewicz, Izabela; Garriga, Rosa; Muñoz, Edgar

    2016-02-01

    A Love-wave device with graphene oxide (GO) as sensitive layer has been developed for the detection of chemical warfare agent (CWA) simulants. Sensitive films were fabricated by airbrushing GO dispersions onto Love-wave devices. The resulting Love-wave sensors detected very low CWA simulant concentrations in synthetic air at room temperature (as low as 0.2 ppm for dimethyl-methylphosphonate, DMMP, a simulant of sarin nerve gas, and 0.75 ppm for dipropylene glycol monomethyl ether, DPGME, a simulant of nitrogen mustard). High responses to DMMP and DPGME were obtained with sensitivities of 3087 and 760 Hz/ppm respectively. Very low limit of detection (LOD) values (9 and 40 ppb for DMMP and DPGME, respectively) were calculated from the achieved experimental data. The sensor exhibited outstanding sensitivity, good linearity and repeatability to all simulants tested. The detection mechanism is here explained in terms of hydrogen bonding formation between the tested CWA simulants and GO.

  17. Minimal erythema dose and minimal melanogenesis dose relate better to objectively measured skin type than to Fitzpatricks skin type

    DEFF Research Database (Denmark)

    Wulf, Hans Christian; Philipsen, Peter A; Ravnbak, Mette H

    2010-01-01

    Fitzpatrick skin type (FST I-IV) is a subjective expression of ultraviolet (UV) sensitivity based on erythema and tanning reactivity after a single exposure. Pigment protection factor (PPF) is an objective measurement of skin sensitivity in all skin types after a single exposure.......Fitzpatrick skin type (FST I-IV) is a subjective expression of ultraviolet (UV) sensitivity based on erythema and tanning reactivity after a single exposure. Pigment protection factor (PPF) is an objective measurement of skin sensitivity in all skin types after a single exposure....

  18. 0.1%他克莫司软膏治疗成年人面部敏感性皮肤的疗效和观察%Efficacy and safety of tacrolimus ointment for facial sensitive skin in adults

    Institute of Scientific and Technical Information of China (English)

    曹源; 谢志强; 张春雷

    2016-01-01

    目的:观察0.1%的他克莫司软膏治疗成年人面部敏感性皮肤的疗效和安全性。方法给予36例诊断为敏感性皮肤的患者外用0.1%他克莫司软膏,每日2次,共3周,如果用药不到3周痊愈,可停止用药。于治疗前及治疗后1、3周和停药后4周各随访1次,评估病情严重程度及临床疗效。采用皮肤病生活质量调查问卷评估敏感性皮肤对生活质量的影响。结果36例患者中32例完成临床试验。治疗3周后皮炎症状的临床痊愈率、显效率分别为46.9%、40.6%,有效率为87.5%。治疗3周后10项评估指标及生活质量均有明显改善(P <0.001)。主观症状改善最明显的是自觉干燥、针刺感。客观症状中脱屑、干燥症状对治疗的反应最好。药物不良反应发生率为72.2%(瘙痒占30.8%,烧灼感占69.2%,刺痛占7.7%),其中有50%只出现于用药后2d 内。结论0.1%他克莫司软膏治疗成年人面部敏感性皮肤安全、有效,刺激反应较普遍,多为一过性,可耐受。%Objective To investigate the clinical efficacy and safety of topical 0.1% tacrolimus ointment in the treatment of adults patient with facial sensitive skin. Methods Total 36 cases were treated with topical 0.1% tacrolimus ointment, twice daily, and the clinical symptom and sign scores were recorded before and after the treatment. A new scale, which including 6 subjective skin conditions (pricking, burning sensation, itching, pain, dry sensation, tightness) and 4 visible skin conditions (erythema, swelling, scaling, dryness) was adopted for assessment at the baseline and succeeding improvement of skin condition. Dermatology life quality index was used to evaluate the impact of sensitive skin on life quality. Meanwhile the adverse events were observed. Results Thirty-two of the 36 cases completed the whole course of treatment. The cure rate was 46.9%(15/32), markedly improvement rate was 40.6%(13/32), moderate

  19. Old and stable soil organic matter is not necessarily chemically recalcitrant: Implications for modeling concepts and temperature sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Kleber, M.; Nico, P.S.; Plante, A.; Filley, T.; Kramer, M.; Swanston, C.; Sollins, P.

    2010-03-01

    Soil carbon turnover models generally divide soil carbon into pools with varying intrinsic decomposition rates. Although these decomposition rates are modified by factors such as temperature, texture, and moisture, they are rationalized by assuming chemical structure is a primary controller of decomposition. In the current work, we use near edge X-ray absorption fine structure (NEXAFS) spectroscopy in combination with differential scanning calorimetry (DSC) and alkaline cupric oxide (CuO) oxidation to explore this assumption. Specifically, we examined material from the 2.3-2.6 kg L{sup -1} density fraction of three soils of different type (Oxisol, Alfisol, Inceptisol). The density fraction with the youngest {sup 14}C age (Oxisol, 107 years) showed the highest relative abundance of aromatic groups and the lowest O-alkyl C/aromatic C ratio as determined by NEXAFS. Conversely, the fraction with the oldest C (Inceptisol, 680 years) had the lowest relative abundance of aromatic groups and highest O-alkyl C/aromatic C ratio. This sample also had the highest proportion of thermally labile materials as measured by DSC, and the highest ratio of substituted fatty acids to lignin phenols as indicated by CuO oxidation. Therefore, the organic matter of the Inceptisol sample, with a {sup 14}C age associated with 'passive' pools of carbon (680 years), had the largest proportion of easily metabolizable organic molecules with low thermodynamic stability, whereas the organic matter of the much younger Oxisol sample (107 years) had the highest proportion of supposedly stable organic structures considered more difficult to metabolize. Our results demonstrate that C age is not necessarily related to molecular structure or thermodynamic stability, and we suggest that soil carbon models would benefit from viewing turnover rate as codetermined by the interaction between substrates, microbial actors, and abiotic driving variables. Furthermore, assuming that old carbon is composed

  20. Hand wash and manual skin wipes

    NARCIS (Netherlands)

    Brouwer, D.H.; Boeniger, M.F.; Hemmen, J. van

    2000-01-01

    Hand wash and skin wipes are major techniques that have been used for dermal exposure sampling. Both techniques remove chemicals either deposited on or transferred to the skin contaminant layer by a combination of chemical and mechanical actions. The paper overviews identified methods and techniques

  1. Aging skin.

    Science.gov (United States)

    Bolognia, J L

    1995-01-16

    Aging of the skin is a composite of actinic damage, chronologic aging, and hormonal influences. The majority of changes associated with aging, such as wrinkles and solar lentigines ("liver spots"), are due to photoaging and reflect cumulative sun exposure as well as skin pigmentation. Classically, chronologic aging includes those cutaneous changes that occur in non-sun-exposed areas, such as the buttocks, and are observed in both men and women. A clinical example would be soft tissue sagging due to elastic fiber degeneration. In women, investigations into the effect of hormones on aging of the skin have concentrated on estrogens; in men, there have been a limited number of studies on the influence of testosterone. The latter have shown an age-dependent decrease in tissue androgens in pubic skin, but not scrotal or thigh skin. To date, age has not been shown to have an effect on androgen receptor binding, although a decrease in foreskin 5 alpha-reductase activity with increasing age has been described. In fibroblast cultures from foreskins, there have been conflicting results as to whether 5 alpha-reductase activity decreases in an age-dependent manner. Some of the skin changes that have been categorized as secondary to chronologic aging, such as decreased sebaceous gland activity and decreased hair growth, may actually represent a decline in the concentration of tissue androgens with increasing age. The influence of androgens on age-related changes in keratinocyte and fibroblast function remains speculative.

  2. Human skin volatiles: a review.

    Science.gov (United States)

    Dormont, Laurent; Bessière, Jean-Marie; Cohuet, Anna

    2013-05-01

    Odors emitted by human skin are of great interest to biologists in many fields; applications range from forensic studies to diagnostic tools, the design of perfumes and deodorants, and the ecology of blood-sucking insect vectors of human disease. Numerous studies have investigated the chemical composition of skin odors, and various sampling methods have been used for this purpose. The literature shows that the chemical profile of skin volatiles varies greatly among studies, and the use of different sampling procedures is probably responsible for some of these variations. To our knowledge, this is the first review focused on human skin volatile compounds. We detail the different sampling techniques, each with its own set of advantages and disadvantages, which have been used for the collection of skin odors from different parts of the human body. We present the main skin volatile compounds found in these studies, with particular emphasis on the most frequently studied body regions, axillae, hands, and feet. We propose future directions for promising experimental studies on odors from human skin, particularly in relation to the chemical ecology of blood-sucking insects.

  3. Skin Cancer Prevention

    Science.gov (United States)

    ... Genetics of Skin Cancer Skin Cancer Screening Research Skin Cancer Prevention (PDQ®)–Patient Version What is prevention? ... prevent cancer are being studied. General Information About Skin Cancer Key Points Skin cancer is a disease ...

  4. Skin Cancer Screening

    Science.gov (United States)

    ... Genetics of Skin Cancer Skin Cancer Screening Research Skin Cancer Screening (PDQ®)–Patient Version What is screening? ... These are called diagnostic tests . General Information About Skin Cancer Key Points Skin cancer is a disease ...

  5. Dry Skin (Xerosis)

    Science.gov (United States)

    ... Kids’ zone Video library Find a dermatologist Dry skin Overview Dry, ashy skin: People who had atopic ... often have very dry skin as adults. Dry skin: Overview Also called xerosis Dry skin is common. ...

  6. Beneficial effects of pro-/antioxidant-based nutraceuticals in the skin rejuvenation techniques.

    Science.gov (United States)

    de Luca, C; Deeva, I; Mikhal'Chik, E; Korkina, L

    2007-04-15

    Modern technologies of skin rejuvenation include many physical and chemical intervention tools--laser irradiation, oxygen and ozone therapy, chemical peels, plastic surgery operations--affecting by different mechanisms the sensitive physiological free radical/antioxidant balance in the skin. All these interventions induce from mild to severe tissue damage, providing beneficial biochemical stimuli for skin re-epithelization and rejuvenation. Paradoxically, free radical production in the course of tissue inflammation helps to combat free radical damage consequent to the ageing process. We have studied two animal models (experimental burn and trichloracetic peeling), reproducing on the Wistar rat the effects generated by the commonly practiced aesthetic medicine procedures of laser resurfacing and chemical peels, demonstrating that the severe oxidative stress induced both systemically and on skin can be modulated by the oral pre- and post treatment administration of specific nutraceutical formulations. Potent antioxidants (RRR-alpha-tocopherol, coenzyme Q10), enhancing antioxidant defences, coupled with mild pro-oxidants, enhancers of a specific immune defense (soy phospholipids, L-methionine), at the blood and the skin levels, proved in fact to be beneficial in vivo, on the rat, for skin healing, trophism and accelerated re-epithelization. Data obtained allow us to predict the possibility of innovative protocols for dermocosmetology, enabling successful lowering of the risk of permanent adverse effects, and prolonging the duration of the beneficial effects of dermocosmetologic procedures.

  7. Mammalian Toxicity of Munitions Compounds. Phase I. Acute Oral Toxicity, Primary Skin and Eye Irritation, Dermal Sensitization, Disposition and Metabolism and Ames Tests of Additional Compounds

    Science.gov (United States)

    1978-12-08

    Assay of 300 Chemicals, Proc. Nat. Acad. Sci., 72:5135-5139, 1975. 17. Wang, C. Y., K. Muraoka, and G. T. Bryan, Yatagenicity of Nitrofurans ...L. H. DiSalvo, and J. Ng, Toxicity and Mutagenicity of 2,4,6-Trinitrotoluene and Its Microbial Metabolites , Appl. Environ. Microbiol., 31:576-580

  8. Sensitive determinations of Cu, Pb, Cd, and Cr elements in aqueous solutions using chemical replacement combined with surface-enhanced laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Yang, X Y; Hao, Z Q; Li, C M; Li, J M; Yi, R X; Shen, M; Li, K H; Guo, L B; Li, X Y; Lu, Y F; Zeng, X Y

    2016-06-13

    In this study, chemical replacement combined with surface-enhanced laser-induced breakdown spectroscopy (CR-SENLIBS) was for the first time applied to improve the detection sensitivities of trace heavy metal elements in aqueous solutions. Utilizing chemical replacement effect, heavy metal ions in aqueous solution were enriched on the magnesium alloy surface as a solid replacement layer through reacting with the high chemical activity metallic magnesium (Mg) within 1 minute. Unitary and mixed solutions with Cu, Pb, Cd, and Cr elements were prepared to construct calibration curves, respectively. The CR-SENLIBS showed a much better detection sensitivity and accuracy for both unitary and mixed solutions. The coefficients of determination R2 of the calibration curves were above 0.96, and the LoDs were of the same order of magnitude, i.e., in the range of 0.016-0.386 μg/mL for the unitary solution, and in the range of 0.025-0.420 μg/mL for the mixed solution. These results show that CR-SENLIBS is a feasible method for improving the detection sensitivity of trace element in liquid sample, which definitely provides a way for wider application of LIBS in water quality monitoring.

  9. Investigating Motivations for Women's Skin Bleaching in Tanzania

    Science.gov (United States)

    Lewis, Kelly M.; Robkin, Navit; Gaska, Karie; Njoki, Lillian Carol

    2011-01-01

    Why do many African women continue to use damaging skin-bleaching cosmetics that contain dangerous chemicals (e.g., mercury) that may increase their rates of infertility, skin cancer, and serious skin/brain/kidney disease? To address this question, our study investigated motivations driving the preservation of skin-bleaching practices in Tanzania.…

  10. Allergic Responses Induced by the Immunomodulatory Effects of Nanomaterials upon Skin Exposure

    Science.gov (United States)

    Yoshioka, Yasuo; Kuroda, Etsushi; Hirai, Toshiro; Tsutsumi, Yasuo; Ishii, Ken J.

    2017-01-01

    Over the past decade, a vast array of nanomaterials has been created through the development of nanotechnology. With the increasing application of these nanomaterials in various fields, such as foods, cosmetics, and medicines, there has been concern about their safety, that is, nanotoxicity. Therefore, there is an urgent need to collect information about the biological effects of nanomaterials so that we can exploit their potential benefits and design safer nanomaterials, while avoiding nanotoxicity as a result of inhalation or skin exposure. In particular, the immunomodulating effect of nanomaterials is one of most interesting aspects of nanotoxicity. However, the immunomodulating effects of nanomaterials through skin exposure have not been adequately discussed compared with the effects of inhalation exposure, because skin penetration by nanomaterials is thought to be extremely low under normal conditions. On the other hand, the immunomodulatory effects of nanomaterials via skin may cause severe problems for people with impaired skin barrier function, because some nanomaterials could penetrate the deep layers of their allergic or damaged skin. In addition, some studies, including ours, have shown that nanomaterials could exhibit significant immunomodulating effects even if they do not penetrate the skin. In this review, we summarize our current knowledge of the allergic responses induced by nanomaterials upon skin exposure. First, we discuss nanomaterial penetration of the intact or impaired skin barrier. Next, we describe the immunomodulating effects of nanomaterials, focusing on the sensitization potential of nanomaterials and the effects of co-exposure of nanomaterials with substances such as chemical sensitizers or allergens, on the onset of allergy, following skin exposure. Finally, we discuss the potential mechanisms underlying the immunomodulating effects of nanomaterials by describing the involvement of the protein corona in the interaction of

  11. Chemical-genetic inhibition of a sensitized mutant myosin Vb demonstrates a role in peripheral-pericentriolar membrane traffic

    OpenAIRE

    Provance, D. William; Gourley, Christopher R.; Silan, Colleen M.; Cameron, L. C.; Kevan M Shokat; Goldenring, James R.; Shah, Kavita; Gillespie, Peter G.; John A. Mercer

    2004-01-01

    Selective, in situ inhibition of individual unconventional myosins is a powerful approach to determine their specific physiological functions. Here, we report the engineering of a myosin Vb mutant that still hydrolyzes ATP, yet is selectively sensitized to an N6-substituted ADP analog that inhibits its activity, causing it to remain tightly bound to actin. Inhibition of the sensitized mutant causes inhibition of accumulation of transferrin in the cytoplasm and increases levels of plasma-membr...

  12. Variability in Human Bitter Taste Sensitivity to Chemically Diverse Compounds Can Be Accounted for by Differential TAS2R Activation.

    Science.gov (United States)

    Roura, Eugeni; Aldayyani, Asya; Thavaraj, Pridhuvi; Prakash, Sangeeta; Greenway, Delma; Thomas, Walter G; Meyerhof, Wolfgang; Roudnitzky, Natacha; Foster, Simon R

    2015-07-01

    The human population displays high variation in taste perception. Differences in individual taste sensitivity may also impact on nutrient intake and overall appetite. A well-characterized example is the variable perception of bitter compounds such as 6-n-propylthiouracil (PROP) and phenylthiocarbamide (PTC), which can be accounted for at the molecular level by polymorphic variants in the specific type 2 taste receptor (TAS2R38). This phenotypic variation has been associated with influencing dietary preference and other behaviors, although the generalization of PROP/PTC taster status as a predictor of sensitivity to other tastes is controversial. Here, we proposed that the taste sensitivities of different bitter compounds would be correlated only when they activate the same bitter taste receptor. Thirty-four volunteers were exposed to 8 bitter compounds that were selected based on their potential to activate overlapping and distinct repertoires of TAS2Rs. Taste intensity ratings were evaluated using the general Labeled Magnitude Scale. Our data demonstrate a strong interaction between the intensity for bitter substances when they activate common TAS2Rs. Consequently, PROP/PTC sensitivity was not a reliable predictor of general bitter sensitivity. In addition, our findings provide a novel framework to predict taste sensitivity based on their specific T2R activation profile.

  13. Transient receptor potential ankyrin 1 activation enhances hapten sensitization in a T-helper type 2-driven fluorescein isothiocyanate-induced contact hypersensitivity mouse model

    Energy Technology Data Exchange (ETDEWEB)

    Shiba, Takahiro; Tamai, Takuma; Sahara, Yurina; Kurohane, Kohta [Laboratory of Microbiology and Immunology, School of Pharmaceutical Sciences, University of Shizuoka, 52‐1 Yada, Suruga-ku, Shizuoka City, Shizuoka 422‐8526 (Japan); Watanabe, Tatsuo [Laboratory of Food Chemistry, School of Food and Nutritional Sciences, University of Shizuoka, 52‐1 Yada, Suruga-ku, Shizuoka City, Shizuoka 422‐8526 (Japan); Imai, Yasuyuki, E-mail: imai@u-shizuoka-ken.ac.jp [Laboratory of Microbiology and Immunology, School of Pharmaceutical Sciences, University of Shizuoka, 52‐1 Yada, Suruga-ku, Shizuoka City, Shizuoka 422‐8526 (Japan)

    2012-11-01

    Some chemicals contribute to the development of allergies by increasing the immunogenicity of other allergens. We have demonstrated that several phthalate esters, including dibutyl phthalate (DBP), enhance skin sensitization to fluorescein isothiocyanate (FITC) in a mouse contact hypersensitivity model, in which the T-helper type 2 (Th2) response is essential. On the other hand, some phthalate esters were found to activate transient receptor potential ankyrin 1 (TRPA1) cation channels on sensory neurons. We then found a positive correlation between the enhancing effects of several types of phthalate esters on skin sensitization to FITC and their ability to activate TRPA1. Here we examined the involvement of TRPA1 in sensitization to FITC by using TRPA1 agonists other than phthalate esters. During skin sensitization to FITC, the TRPA1 agonists (menthol, carvacrol, cinnamaldehyde and DBP) augmented the ear-swelling response as well as trafficking of FITC-presenting dendritic cells to draining lymph nodes. We confirmed that these TRPA1 agonists induced calcium influx into TRPA1-expressing Chinese hamster ovary (CHO) cells. We also found that TRPA1 antagonist HC-030031 inhibited DBP-induced calcium influx into TRPA1-expressing CHO cells. After pretreatment with this antagonist upon skin sensitization to FITC, the enhancing effect of DBP on sensitization was suppressed. These results suggest that TRPA1 activation will become a useful marker to find chemicals that facilitate sensitization in combination with other immunogenic haptens. -- Highlights: ► Role of TRPA1 activation was revealed in a mouse model of skin sensitization to FITC. ► TRPA1 agonists enhanced skin sensitization as well as dendritic cell trafficking. ► Dibutyl phthalate (DBP) has been shown to enhance skin sensitization to FITC. ► TRPA1 activation by DBP was inhibited by a selective antagonist, HC-030031. ► HC-030031 inhibited the enhancing effect of DBP on skin sensitization to FITC.

  14. Optical skin friction measurement using shear-sensitive liquid-crystal coatings%基于剪敏液晶涂层的光学摩阻测量技术研究

    Institute of Scientific and Technical Information of China (English)

    陈星; 毕志献; 宫建; 姚大鹏; 文帅

    2012-01-01

    剪切敏感液晶涂层具有对剪切应力敏感的光学特性,液晶涂层的显色不但与所受到的应力大小有关,而且与应力方向有关.在白色光垂直照射下,利用相机拍摄液晶涂层所反射的空间光谱图像,结合标定结果可以获得涂层受到的表面剪切应力矢量分布.基于这样的理论,开展了液晶涂层光学摩阻测量技术研究,包括:液晶材料喷涂工艺研究,搭建相应的测量系统,液晶涂层标定方法研究,表面摩阻测量实验研究等.低速喷流实验定量测量了喷流—平板干扰区表面剪切应力矢量分布.Ma=5的高超声速风洞实验获得了尖前缘平板表面摩阻分布定量测量结果,以此判断了平板边界层的转捩.%Shear-sensitive liquid-crystal coatings (SSLCCs) have an optical characteristic that is sensitive to the applied shear stress. Color-change response of a liquid-crystal coating (LCC) depends on both the magnitude of the applied shear vector and its direction. Images of spatial reflection spectrum of the LCC with illumination of white light from normal direction can be gained utilizing a camera, and then processed to get the surface shear stress vector distribution on the coating with the calibration data. Based on this theory, we did investigations on skin friction measurement using the LCCs, including spraying skills of the liquid crystals, construction of a measurement system, shear calibration, experimental measurement of skin friction and so on. In the low speed jet flow experiment, surface shear stress vector distribution in a jet flow/flat plate interaction region was quantitatively measured. In the Ma = 5 hypersonic wind tunnel experiment, distribution of skin friction on a sharp leading edge flat plate was obtained, from which the flat plate boundary layer transition could be determined.

  15. Skin-inspired electronic devices

    Directory of Open Access Journals (Sweden)

    Alex Chortos

    2014-09-01

    Full Text Available Electronic devices that mimic the properties of skin have potential important applications in advanced robotics, prosthetics, and health monitoring technologies. Methods for measuring tactile and temperature signals have progressed rapidly due to innovations in materials and processing methods. Imparting skin-like stretchability to electronic devices can be accomplished by patterning traditional electronic materials or developing new materials that are intrinsically stretchable. The incorporation of sensing methods with transistors facilitates large-area sensor arrays. While sensor arrays have surpassed the properties of human skin in terms of sensitivity, time response, and device density, many opportunities remain for future development.

  16. Influence of the physical–chemical properties of polyaniline thin films on the final sensitivity of varied field effect sensors

    Energy Technology Data Exchange (ETDEWEB)

    Mello, Hugo José Nogueira Pedroza Dias, E-mail: hugodiasmello@usp.br; Heimfarth, Tobias; Mulato, Marcelo

    2015-06-15

    We investigated the use of electrodeposited polyaniline (PANI) thin sensing films in pH sensors. Two configurations of the Extended Gate Field Effect Transistor (EGFET) sensor were studied: the Single EGFET (S-EGFET) and the Instrumental Amplifier EGFET (IA-EGFET) setups. The films were analyzed in both systems and the sensitivity and linearity of each sensor were compared. Initial sensitivities (70–80 mV/pH) measured in the IA-EGFET were reduced due to polymer bulk protonation after a prior measurement in the S-EGFET system. Films with high amount of deposited polymer had their sensitivities least reduced. Bulk protonation occurred due to the step potential applied to the reference electrode in the S-EGFET system. These changes were also analyzed by scanning electron microscopy (SEM), visible reflectance spectroscopy and evaluation of CIE L*a*b* color scale. PANI pH EGFET sensors exhibited good linearity and stability that along with their high sensitivity, easy processing and low cost film production have large potential applications. - Highlights: • Electrodeposited polyaniline thin films were analyzed in two EGFET setups. • Polymer protonation provided changeable sensitivities. • Color and morphological variation confirm polymer aggregation and electrical changes.

  17. Skin Cancer

    Science.gov (United States)

    ... you ever get a bad sunburn that caused blisters when you were a child?Does your skin ... Cancer InstituteMelanoma International FoundationAmerican Cancer Society ResourcesDiagnosis and Management of Malignant Melanoma by BG Goldstein, AO Goldstein( ...

  18. Demonstration of a rapidly-swept external cavity quantum cascade laser for rapid and sensitive quantification of chemical mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Brumfield, Brian E.; Taubman, Matthew S.; Phillips, Mark C.

    2016-02-13

    A rapidly-swept external cavity quantum cascade laser (ECQCL) system for fast open-path quantification of multiple chemicals and mixtures is presented. The ECQCL system is swept over its entire tuning range (>100 cm-1) at frequencies up to 200 Hz. At 200 Hz the wavelength tuning rate and spectral resolution are 2x104 cm-1/sec and < 0.2 cm-1, respectively. The capability of the current system to quantify changes in chemical concentrations on millesecond timescales is demonstrated at atmospheric pressure using an open-path multi-pass cell. The detection limits for chemicals ranged from ppb to ppm levels depending on the absorption cross-section.

  19. pH-sensitive transformation of the peptidic bolaamphiphile self-assembly: exploitation for the pH-triggered chemical reaction.

    Science.gov (United States)

    Kwak, Jinyoung; Lee, Sang-Yup

    2014-03-01

    Control of the macroscopic self-assembled structure of the amphiphilic molecule has been a challenging issue in micro/nanotechnologies. In this study, the microtubular self-assembly of a novel peptidic bolaamphiphile, bis(N-α-amido-glycylglycine)-1,10-decene dicarboxylate, which undergoes reversible structural transformation between microtubes and precipitates as a function of pH, was exploited for pH-triggered chemical release. At neutral and basic conditions above a pH of 6, the peptidic bolaamphiphilic molecule self-assembled to form tubular structures several hundreds of micrometers in length. When the solution became acidic below a pH of 4, the tubular assembly disintegrated to form aggregated precipitates. The reversible transformation of precipitate to microtube was achieved by raising the pH above 6. From the Raman spectroscopy results, it was revealed that the hydrogen bonds of the amide group and carboxylate were enhanced under the acidic conditions. These variation of the hydrogen bonds resulted in precipitation of peptidic bolaamphiphilic molecules while rupturing the microtubular structure. The pH-sensitive microscopic structural transformation was exploited for release of a chemical in which the pH-triggered release of a model chemical, a fluorescence dye of ANS, was demonstrated. The ANS dye was released gradually with decreasing pH, which suggests gradual disintegration of the microtubular self-assembly. Furthermore, this pH-triggered release of a chemical was exploited for the chemical reaction of gold ion reduction to produce solid clusters. This study demonstrated the reversible transformation of peptidic bolaamphiphile and its application as a pH-sensitive host matrix.

  20. Squamous cell skin cancer

    Science.gov (United States)

    ... that reflect light more, such as water, sand, concrete, and areas that are painted white. The higher ... - skin - squamous cell; Skin cancer - squamous cell; Nonmelanoma skin cancer - squamous ...

  1. Minimal erythema dose and minimal melanogenesis dose relate better to objectively measured skin type than to Fitzpatricks skin type

    DEFF Research Database (Denmark)

    Wulf, Hans Christian; Philipsen, Peter A; Ravnbak, Mette H

    2010-01-01

    Fitzpatrick skin type (FST I-IV) is a subjective expression of ultraviolet (UV) sensitivity based on erythema and tanning reactivity after a single exposure. Pigment protection factor (PPF) is an objective measurement of skin sensitivity in all skin types after a single exposure....

  2. Contact dermatitis and other skin conditions in instrumental musicians

    Directory of Open Access Journals (Sweden)

    Freitag Marcus

    2004-04-01

    Full Text Available Abstract Background The skin is important in the positioning and playing of a musical instrument. During practicing and performing there is a permanent more or less intense contact between the instrument and the musician's skin. Apart from aggravation of predisposed skin diseases (e.g., atopic eczema or psoriasis due to music-making, specific dermatologic conditions may develop that are directly caused by playing a musical instrument. Methods To perform a systematic review on instrument-related skin diseases in musicians we searched the PubMed database without time limits. Furthermore we studied the online bibliography "Occupational diseases of performing artist. A performing arts medicine bibliography. October, 2003" and checked references of all selected articles for relevant papers. Results The most prevalent skin disorders of instrumental musicians, in particular string instrumentalists (e.g., violinists, cellists, guitarists, woodwind players (e.g., flautists, clarinetists, and brass instrumentalists (e.g., trumpeters, include a variety of allergic contact sensitizations (e.g., colophony, nickel, and exotic woods and irritant (physical-chemical noxae skin conditions whose clinical presentation and localization are usually specific for the instrument used (e.g., "fiddler's neck", "cellist's chest", "guitar nipple", "flautist's chin". Apart from common callosities and "occupational marks" (e.g., "Garrod's pads" more or less severe skin injuries may occur in musical instrumentalists, in particular acute and chronic wounds including their complications. Skin infections such as herpes labialis seem to be a more common skin problem in woodwind and brass instrumentalists. Conclusions Skin conditions may be a significant problem not only in professional instrumentalists, but also in musicians of all ages and ability. Although not life threatening they may lead to impaired performance and occupational hazard. Unfortunately, epidemiological

  3. Chemical-genetic inhibition of a sensitized mutant myosin Vb demonstrates a role in peripheral-pericentriolar membrane traffic.

    Science.gov (United States)

    Provance, D William; Gourley, Christopher R; Silan, Colleen M; Cameron, L C; Shokat, Kevan M; Goldenring, James R; Shah, Kavita; Gillespie, Peter G; Mercer, John A

    2004-02-17

    Selective, in situ inhibition of individual unconventional myosins is a powerful approach to determine their specific physiological functions. Here, we report the engineering of a myosin Vb mutant that still hydrolyzes ATP, yet is selectively sensitized to an N(6)-substituted ADP analog that inhibits its activity, causing it to remain tightly bound to actin. Inhibition of the sensitized mutant causes inhibition of accumulation of transferrin in the cytoplasm and increases levels of plasma-membrane transferrin receptor, suggesting that myosin Vb functions in traffic between peripheral and pericentrosomal compartments.

  4. Chemical burn or reaction

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000059.htm Chemical burn or reaction To use the sharing features on this page, please enable JavaScript. Chemicals that touch skin can lead to a reaction on the skin, throughout the body, or both. ...

  5. The effect of chemical information on the spatial distribution of fruit flies: II parameterization, calibration, and sensitivity

    NARCIS (Netherlands)

    Gee, de M.; Lof, M.E.; Hemerik, L.

    2008-01-01

    In a companion paper (Lof et al., in Bull. Math. Biol., 2008), we describe a spatio-temporal model for insect behavior. This model includes chemical information for finding resources and conspecifics. As a model species, we used Drosophila melanogaster, because its behavior is documented comparative

  6. Airway morphology and function of rats following dermal sensitization and respiratory challenge with low molecular weight chemicals

    NARCIS (Netherlands)

    Arts, J.H.E.; Kuper, C.F.; Spoor, S.M.; Bloksma, N.

    1998-01-01

    Local lymph node activation and increased total serum IgE levels are suggested to be predictive parameters of airway hypersensitivity caused by low molecular weight (LMW) chemicals. Whether increases of total serum IgE are indicative of actual induction of specific airway reactions (morphological an

  7. 改性塔拉微粉兔皮复鞣工艺中的应用%Chemical Modification of Tara Powder and Application in Rabbit Skin

    Institute of Scientific and Technical Information of China (English)

    吴樊花; 刘公岩; 张宗才

    2013-01-01

    The tara powder was modified and applied in the retanning of rabbit skin.The shrink-temperature and the free formaldehyde content of the skin retanned by modified-tara were determined.The result shows that the application of modified tara in retanning decreases the formaldehyde dosage used in the process.The solftness and fullness of the fur tanned by this method are well,which comply with the requirements of eco-fur.%对塔拉微粉进行改性后,将其应用于兔皮复鞣工艺中,考察了兔皮的收缩温度及游离甲醛含量等指标,结果表明:在复鞣阶段使用改性塔拉单宁,大大降低了兔皮复鞣工艺中甲醛的用量,且鞣制后兔皮皮板的丰满度、弹性较好,符合生态裘皮的要求.

  8. A controlled study of the effect of a mindfulness-based stress reduction technique in women with multiple chemical sensitivity, chronic fatigue syndrome, and fibromyalgia

    Directory of Open Access Journals (Sweden)

    Tara Sampalli

    2009-04-01

    Full Text Available Tara Sampalli1, Elizabeth Berlasso1, Roy Fox1, Mark Petter21Nova Scotia Environmental Health Centre, Fall River, Nova Scotia, Canada; 2Doctoral Candidate, Department of Psychology, Dalhousie University, Halifax, CanadaBackground: The objective of this study was to examine the effect of a mindfulness-based stress reduction (MBSR program on women diagnosed with conditions such as multiple chemical sensitivity (MCS, chronic fatigue syndrome (CFS, and fibromyalgia (FM. Methods: The intervention group underwent a 10-week MBSR program. Symptoms Checklist Inventory (SCL-90R was used as outcome measure and was administered before the start of the program (pre-, immediately upon completion (post- and at three-month follow-up. Women on the wait list to receive treatment at the Nova Scotia Environmental Health Centre were used as control subjects for the study.Results: A total of 50 participants in the intervention group and 26 in the wait-list controls group were recruited for this study. Global scores in the intervention group reached statistical significance pre-post (<0.0001 and at pre-follow-up (<0.0001 while the global scores in the control group remained the same. Five of nine and eight of nine subscales of the SCL-90R showed improvement of statistical significance in MBSR group following treatment and at three-month follow-up.Conclusions: The study showed the importance of complementary interventions such as MBSR techniques in the reduction of psychological distress in women with chronic conditions.Keywords: chronic conditions, multiple chemical sensitivity, mindfulness-based stress reduction, chemical sensitivity

  9. Detection of chemical vapor with high sensitivity by using the symmetrical metal-cladding waveguide-enhanced Goos-Hänchen shift.

    Science.gov (United States)

    Nie, Yiyou; Li, Yuanhua; Wu, Zhijing; Wang, Xianping; Yuan, Wen; Sang, Minghuang

    2014-04-21

    We present a novel and simple optical structure, i.e., the symmetrical metal-cladding waveguide, in which a polymer layer is added into the guiding layer, for sensitive detection of chemical vapor by using the enhanced Goos-Hänchen (GH) shift (nearly a millimeter scale). Owing to the high sensitivity of the excited ultrahigh-order modes, the vapor-induced effect (swelling effect and refractive index change) in the polymer layer will lead to a dramatic variation of the GH shift. The detected GH shift signal is irrelevant to the power fluctuation of the incident light. The detection limit of 9.5 ppm for toluene and 28.5 ppm for benzene has been achieved.

  10. Skin Cancer Foundation

    Science.gov (United States)

    ... Host a Fundraising Event | About Us | Store The Skin Cancer Foundation The Skin Cancer Foundation is the ... A "Sunscreen Gene"? Skin Cancer Facts & Statistics The Skin Cancer Foundation's Champions for Change Gala 2016 Learn ...

  11. Skin Pigmentation Disorders

    Science.gov (United States)

    Pigmentation means coloring. Skin pigmentation disorders affect the color of your skin. Your skin gets its color from a pigment called melanin. Special cells in the skin make melanin. When these cells become damaged or ...

  12. Influence of metabolism in skin on dosimetry after topical exposure.

    OpenAIRE

    1994-01-01

    Metabolism of chemicals occurs in skin and therefore should be taken into account when one determines topical exposure dose. Skin metabolism is difficult to measure in vivo because biological specimens may also contain metabolites from other tissues. Metabolism in skin during percutaneous absorption can be studied with viable skin in flow-through diffusion cells. Several compounds metabolized by microsomal enzymes in skin (benzo[a]pyrene and 7-ethoxycoumarin) penetrated human and hairless gui...

  13. Porcine skin flow-through diffusion cell system.

    Science.gov (United States)

    Baynes, R E

    2001-11-01

    Porcine Skin Flow-Through Diffusion Cell System (Ronald E. Baynes, North Carolina State University, Raleigh, North Carolina). Porcine skin can be used in a diffusion cell apparatus to study the rate and extent of absorption of topically applied chemicals through the skin. Although the skin of a number of animals can be used in this system, that of the pig most closely approximates human skin anatomically and physiologically.

  14. Experimental Verification of the Chemical Sensitivity of Two-Site Double Core-Hole States Formed by an X-ray FEL

    CERN Document Server

    Salen, P; Schmidt, H T; Thomas, R D; Larsson, M; Feifel, R; Piancastelli, M N; Fang, L; Murphy, B; Osipov, T; Berrah, N; Kukk, E; Ueda, K; Bozek, J D; Bostedt, C; Wada, S; Richter, R; Feyer, V; Prince, K C

    2012-01-01

    We have performed X-ray two-photon photoelectron spectroscopy (XTPPS) using the Linac Coherent Light Source (LCLS) X-ray free-electron laser (FEL) in order to study double core-hole (DCH) states of CO2, N2O and N2. The experiment verifies the theory behind the chemical sensitivity of two-site (ts) DCH states by comparing a set of small molecules with respect to the energy shift of the tsDCH state and by extracting the relevant parameters from this shift.

  15. Skin Bleaching

    OpenAIRE

    Ahmed, Samira M.

    2015-01-01

    In this project, I aim to investigate the reasoning behind the practice of skin bleaching by analyzing the documentary ”Dark Girls”, to gain a better understanding of race and colorism issues. Also this project tries to see if there is a connection with history and if this has been a part of making the european beauty ideal determine the choices black’s make in regards to beauty.

  16. Influence of NH{sub 3}.H{sub 2}O additive on the photovoltaic performance of dye-sensitized solar cells with chemical sintered scattering layers

    Energy Technology Data Exchange (ETDEWEB)

    Lan Zhang, E-mail: lanzhang@hqu.edu.cn [Engineering Research Center of Environment-Friendly Functional Materials, Ministry of Education, Huaqiao University, Quanzhou 362021 (China); Key Laboratory of Functional Materials for Fujian Higher Education, Huaqiao University, Quanzhou 362021 (China); Institute of Materials Physical Chemistry, Huaqiao University, Quanzhou 362021 (China); Wu Jihuai, E-mail: jhwu@hqu.edu.cn [Engineering Research Center of Environment-Friendly Functional Materials, Ministry of Education, Huaqiao University, Quanzhou 362021 (China); Key Laboratory of Functional Materials for Fujian Higher Education, Huaqiao University, Quanzhou 362021 (China); Institute of Materials Physical Chemistry, Huaqiao University, Quanzhou 362021 (China); Lin Jianming; Huang, Miaoliang [Engineering Research Center of Environment-Friendly Functional Materials, Ministry of Education, Huaqiao University, Quanzhou 362021 (China); Key Laboratory of Functional Materials for Fujian Higher Education, Huaqiao University, Quanzhou 362021 (China); Institute of Materials Physical Chemistry, Huaqiao University, Quanzhou 362021 (China)

    2011-11-30

    Graphical abstract: Chemical sintered bi-functional nanocrystalline TiO{sub 2} layers for highly efficient photoelectrodes. Display Omitted Highlights: > A chemical sintered bi-functional nanocrystalline TiO{sub 2} layer was prepared. > The nanocrystalline TiO{sub 2} layer can offer both light-scattering and electron generating properties. > The DSSC with this nanocrystalline TiO{sub 2} layer in the photoelectrode shows obviously enhanced photovoltaic performance. > The influence of additional amount of NH{sub 3}.H{sub 2}O chemical sintering agent on the photovoltaic performance of DSSCs was studied. - Abstract: A bi-functional nanocrystalline TiO{sub 2} (nc-TiO{sub 2}) layer able to offer both light-scattering and electron generating properties was prepared with a simple method through adding the basic NH{sub 3}.H{sub 2}O agent into an acid nc-TiO{sub 2} paste to form some big rod-like nc-TiO{sub 2} aggregates by the chemical sintering process. The influence of additional amount of NH{sub 3}.H{sub 2}O on the photovoltaic performance of the dye-sensitized solar cell with this bi-functional nc-TiO{sub 2} layer in the photoelectrode was studied. It was found that through controlling the additional amount of NH{sub 3}.H{sub 2}O and the thickness of the bi-functional nc-TiO{sub 2} layer, the highest energy conversion efficiency about 8.11% could be obtained, which was much higher than that of the dye-sensitized solar cell containing a single nc-TiO{sub 2} layer prepared with the original acid nc-TiO{sub 2} paste (4.34%).

  17. A strategy for skin irritation testing.

    Science.gov (United States)

    Robinson, Michael K; Perkins, Mary A

    2002-03-01

    Skin irritation safety testing and risk assessment for new products, and the ingredients they contain, is a critical requirement before market introduction. In the past, much of this skin testing required the use of experimental animals. However, new current best approaches for skin corrosion and skin irritation testing and risk assessment are being defined, obviating the need for animal test methods. Several in vitro skin corrosion test methods have been endorsed after successful validation and are gaining acceptance by regulatory authorities. In vitro test methods for acute, cumulative (repeat exposure), and chronic (prolonged exposure) skin irritation are under development. Though not yet validated, many are being used successfully for testing and risk assessment purposes as documented through an expanding literature. Likewise, a novel acute irritation patch test in human subjects is providing a valid and ethical alternative to animal testing for prediction of chemical skin irritation potential. An array of other human test methods also have been developed and used for the prediction of cumulative/chronic skin irritation and the general skin compatibility of finished products. The development of instrumental methods (e.g., transepidermal water loss, capacitance, and so on) has provided the means for analyzing various biophysical properties of human skin and changes in these properties caused by exposure to irritants. However, these methods do not directly measure skin inflammation. A recently introduced skin surface tape sampling procedure has been shown to detect changes in skin surface cytokine recovery that correlate with inflammatory skin changes associated with chemical irritant exposures or existing dermatitis. It holds promise for more objective quantification of skin irritation events, including subclinical (sensory) irritation, in the future.

  18. The Different Sensitive Behaviors of a Hydrogen-Bond Acidic Polymer-Coated SAW Sensor for Chemical Warfare Agents and Their Simulants

    Directory of Open Access Journals (Sweden)

    Yin Long

    2015-07-01

    Full Text Available A linear hydrogen-bond acidic (HBA linear functionalized polymer (PLF, was deposited onto a bare surface acoustic wave (SAW device to fabricate a chemical sensor. Real-time responses of the sensor to a series of compounds including sarin (GB, dimethyl methylphosphonate (DMMP, mustard gas (HD, chloroethyl ethyl sulphide (2-CEES, 1,5-dichloropentane (DCP and some organic solvents were studied. The results show that the sensor is highly sensitive to GB and DMMP, and has low sensitivity to HD and DCP, as expected. However, the sensor possesses an unexpected high sensitivity toward 2-CEES. This good sensing performance can’t be solely or mainly attributed to the dipole-dipole interaction since the sensor is not sensitive to some high polarity solvents. We believe the lone pair electrons around the sulphur atom of 2-CEES provide an electron-rich site, which facilitates the formation of hydrogen bonding between PLF and 2-CEES. On the contrary, the electron cloud on the sulphur atom of the HD molecule is offset or depleted by its two neighbouring strong electron-withdrawing groups, hence, hydrogen bonding can hardly be formed.

  19. Understanding Chemical Sensitivity and Surface Response in Detecting Trace Levels of Explosives Using Vibrational Sum Frequency Spectroscopy

    Science.gov (United States)

    2013-11-04

    does not degrade contaminants on surfaces, a positive detection result leaves any explosives detected in place for subsequent forensic analysis...applications. Optical sum-frequency generation (SFG) has long been used for studying surface chemistry [Lambert et al., 2005; Shen, 2000]. SFG is...present on surfaces at low concentrations, surface selectivity and high sensitivity to surface chemistry are key advantages of VSFS in detecting HEs

  20. The evaluation of the impact of age, skin tags, metabolic syndrome, body mass index, and smoking on homocysteine, endothelin-1, high-sensitive C-reactive protein, and on the heart

    Directory of Open Access Journals (Sweden)

    Omar Soliman El Safoury

    2013-01-01

    Full Text Available Background: Skin tags (STs are small, pedunculated skin-colored or brown papules that occur around any site where skin folds occur. The literature is short of comprehensive and controlled clinical studies aimed to evaluate the atherogenic risk factors in patients with STs. Aim of Work: The aim of this study is to evaluate the impact of age, STs, metabolic syndrome (METs, body mass index (BMI, and smoking on homocysteine (Hcy, endothelin-1 (ET-1, high-sensitive C-reactive protein (Hs-CRP, and on cardiovascular diseases. Materials and Methods: This study included 30 cardiac patients with STs, 30 non-cardiac patients with STs, and 30 healthy controls with neither heart disease nor STs. History of smoking, measurement of height, weight, BMI, waist circumference (WC, blood pressure, STs number, color, acanthosis nigricans, estimation of serum level of fasting glucose, triglycerides (TGs, cholesterol, high-dense lipoproteins (HDL, Hcy, ET-1, Hs-CRP, and the presence of the METs were elicited in the three groups. Results: Regarding the Hcy, ET-1, and Hs-CRP, the cardiac-STs group showed the highest levels and the control group showed the least ( P < 0.001. The percents of patients with METs were 56.7% in the cardiac-STs, 40% in the non-cardiac-STs, and 0% in the control group ( P < 0.001. Mean BMI exceeded the limit of obesity in the cardiac-STs group (30.9 ± 3.9 and the non-cardiac-STs group (32.6 ± 6 and was normal in the control group (24.7 ± 2.8. Hyperpigmented STs were present in 66.7% of the cardiac-STs group. Multivariate regression analysis for the independent effectors on Hcy level were the presence of STs ( P < 0.001, METs ( P = 0.001, and BMI ( P = 0.024. Regarding ET-1, the effectors were the presence of STs and METs ( P = 0.032. For Hs-CRP, effectors were the presence of STs ( P < 0.001 and smoking ( P = 0.040. Multivariate logistic regression of the predictors of cardiac disease showed that the independent predictors of the occurrence

  1. Skin protection in the prevention of skin diseases.

    Science.gov (United States)

    Elsner, Peter

    2007-01-01

    Occupational skin diseases comprise a wide spectrum of conditions. Under epidemiological aspects, occupational contact dermatitis that is usually manifested on the hands is the most frequent occupational skin disease with an estimated average incidence rate of 0.7-1.5 cases per 1,000 workers per year. Irritant dermatitis is due to individual susceptibility and the exposure to irritants such as wet work combined with detergents or other hydrophilic irritants or solvents at the workplace. Chronic irritant dermatitis is a risk factor for delayed-type sensitization and subsequently allergic contact dermatitis. It is therefore the prevention of chronic or cumulative irritant dermatitis that is the decisive factor in the prevention of occupational skin disease. Within prevention programs at the workplace, skin protection plays an important, but limited role. Others are technical and organizational means to avoid or reduce skin exposure to irritants and allergens. Educational measures to increase the awareness of workers for workplace hazards and to motivate them to use skin protection measures appropriately are just as important as the careful selection of skin protection materials.

  2. Cutaneous skin tag

    Science.gov (United States)

    Skin tag; Acrochordon; Fibroepithelial polyp ... have diabetes. They are thought to occur from skin rubbing against skin. ... The tag sticks out of the skin and may have a short, narrow stalk connecting it to the surface of the skin. Some skin tags are as long as ...

  3. GTP gamma S causes contraction of skinned frog skeletal muscle via the DHP-sensitive Ca2+ channels of sealed T-tubules.

    Science.gov (United States)

    Somasundaram, B; Tregear, R T; Trentham, D R

    1991-03-01

    We have investigated the involvement of G-proteins in excitation-contraction coupling of fast-twitch skeletal muscle, using a fibre preparation designed to retain intact T-tubules and sarcoplasmic reticulum. The nonhydrolysable analogue of guanosine triphosphate, GTP gamma S (50-500 microM) caused a strong, transient isometric contraction in this preparation. Reduction of ethylene-bis(oxonitrilo)tetraacete (EGTA) in the sealed T-tubules from 5 mM to 0.1 mM lowered the threshold to GTP gamma S and removal of sodium reversibly raised it. The dihydropyridine (DHP) calcium channel antagonists nicardipine and nifedipine allowed a first contraction and then blocked subsequent GTP gamma S action. The phenylalkylamine methoxyverapamil (D-600) did likewise, reversibly, at 10 degrees C. The guanosine diphosphate analogue, GDP beta S, and procaine reversibly blocked the action of GTP gamma S; pertussis toxin also blocked it. Photolytic release of 40-100 microM GTP gamma S within 0.1 s from S-caged GTP gamma S caused contraction after a latent period of 0.3-20 s. We conclude that GTP gamma S can activate contraction in frog skeletal muscle via a route requiring both the integrity of the T-tubular DHP-sensitive calcium channel (DHPr) and the presence of sodium in the sealed T-tubules. We propose that in this preparation GTP gamma S activates a G-protein, which in turn activates the DHPr as a calcium channel and releases stored calcium from within the sealed T-tubule. Implications of these results for the excitation-contraction coupling mechanism in skeletal muscle are discussed.

  4. 青海湖裸鲤体表白点病病原菌的分离与药敏试验%Identification and Drug Sensitivity Test of Pathogenic Bacteria of White-spot Disease From Skin Surface of Gymnocypris przewaiskii

    Institute of Scientific and Technical Information of China (English)

    李增魁; 李长忠; 康明; 圈华; 张勤文; 刘道鑫; 马东红; 夏若措毛; 李英

    2015-01-01

    To assure the pathogenic bacteria of white-spot disease from skin surface in Gymnocypris prze-waiskii and treat the disease,three bacterial strains (Citrobacter freundii ,Aeromonas veronii ,Morganella fulton)were isolated from naturally infected Gymnocypris przewaiskii and identified by morphology,cul-tural characteristics,physical and chemical characters,and 16 S rRNA sequence analysis.The three strains were Gram negative.Colony morphologies were consistent.Drug sensitivity test revealed that the three strains were highly sensitive to cefepime,amikacin and gentamicin,which will benefit the treatment of dis-ease in Gymnocypris przewaiskii .%为确定养殖青海湖裸鲤(Gymnocypris przewaiskii )体表白点病的病原,分别对患病鱼白色点状囊泡样物进行了细菌分离、生理生化特性鉴定、16 S rRNA 基因分析和药敏感试验,分离到了以弗氏柠檬酸杆菌(Citrobacter freundii )、维氏气单胞菌(Aeromonas veronii ,AV)和摩氏摩根菌(Morganella fulton )为代表的菌落形态一致、革兰阴性细菌;且分离到的3种菌都对头孢吡肟、丁胺卡那霉素、庆大霉素等药物敏感。

  5. Cutaneous challenge with chemical warfare agents in the SKH-1 hairless mouse (II): effects of some currently used skin decontaminants (RSDL and Fuller's earth) against liquid sulphur mustard and VX exposure.

    Science.gov (United States)

    Taysse, L; Dorandeu, F; Daulon, S; Foquin, A; Perrier, N; Lallement, G; Breton, P

    2011-06-01

    Using the hairless mouse screening model presented in the companion paper(1) the aim of this study was to assess two skin decontaminating systems: Fuller's earth (FE) and Reactive Skin Decontamination Lotion (RSDL) against two extremely toxic chemical warfare agents that represent a special percutaneous hazard, sulphur mustard (SM) and O-ethyl-S-(2[di-isopropylamino]ethyl)methyl-phosphonothioate (VX). Five minutes after being exposed on the back to either 2 µL of neat sulphur mustard or 50 µg.kg(-1) of diluted VX, mice were decontaminated. Both systems were able to reduce blisters 3 days after SM exposure. However, RSDL was found to be more efficient than FE in reducing the necrosis of the epidermis and erosion. In the case of VX exposure, RSDL, whatever the ratio of decontaminant to toxicant used (RSDL 10, 20, 50), was not able to sufficiently prevent the inhibition of plasma cholinesterases taken as a surrogate marker of exposure and toxicity. Only FE reduced significantly the ChE inhibition. Some of these observations are different from our previous results obtained in domestic swine and these changes are thus discussed in the perspective of using SKH-1 hairless mice for the initial in vivo screening of decontaminants.

  6. The skin-blanching assay.

    Science.gov (United States)

    Smit, P; Neumann, H A M; Thio, H B

    2012-10-01

    The skin-blanching assay is used for the determination and bioequivalence of dermatologic glucocorticoids (GCs). The exact mechanism of the production of blanching is not fully understood, but it is considered that local vasoconstriction of the skin microvasculature and the consequent blood-flow reduction cause this phenomenon. Several factors influence skin blanching, including drug concentration, duration of application, nature of vehicle, occlusion, posture and location. The intensity of vasoconstriction can be measured in several ways: visual or quantitative methods, such as reflectance spectroscopy, thermography, laser Doppler velocimetry and chromametry. In literature, contradicting results in the correlation of the skin-blanching assay with different tests to determine GC sensitivity have been reported, limiting its clinical usefulness.

  7. Isoform-specific modulation of the chemical sensitivity of conserved TRPA1 channel in the major honeybee ectoparasitic mite, Tropilaelaps mercedesae

    Science.gov (United States)

    Dong, Xiaofeng; Kashio, Makiko; Peng, Guangda; Wang, Xinyue; Tominaga, Makoto

    2016-01-01

    We identified and characterized the TRPA1 channel of Tropilaelaps mercedesae (TmTRPA1), one of two major species of honeybee ectoparasitic mite. Three TmTRPA1 isoforms with unique N-terminal sequences were activated by heat, and the isoform highly expressed in the mite's front legs, TmTRPA1b, was also activated by 27 plant-derived compounds including electrophiles. This suggests that the heat- and electrophile-dependent gating mechanisms as nocisensitive TRPA1 channel are well conserved between arthropod species. Intriguingly, one TmTRPA1 isoform, TmTRPA1a, was activated by only six compounds compared with two other isoforms, demonstrating that the N-terminal sequences are critical determinants for the chemical sensitivity. This is the first example of isoform-specific modulation of chemical sensitivity of TRPA1 channel in one species. α-terpineol showed repellent activity towards T. mercedesae in a laboratory assay and repressed T. mercedesae entry for reproduction into the brood cells with fifth instar larvae in hives. Thus, α-terpineol could be used as the potential compound to control two major honeybee ectoparasitic mites, T. mercedesae and Varroa destructor, in the apiculture industry. PMID:27307515

  8. Constraining the sensitivity of iodide adduct chemical ionization mass spectrometry to multifunctional organic molecules using the collision limit and thermodynamic stability of iodide ion adducts

    Science.gov (United States)

    Lopez-Hilfiker, Felipe D.; Iyer, Siddarth; Mohr, Claudia; Lee, Ben H.; D'Ambro, Emma L.; Kurtén, Theo; Thornton, Joel A.

    2016-04-01

    The sensitivity of a chemical ionization mass spectrometer (ions formed per number density of analytes) is fundamentally limited by the collision frequency between reagent ions and analytes, known as the collision limit, the ion-molecule reaction time, and the transmission efficiency of product ions to the detector. We use the response of a time-of-flight chemical ionization mass spectrometer (ToF-CIMS) to N2O5, known to react with iodide at the collision limit, to constrain the combined effects of ion-molecule reaction time, which is strongly influenced by mixing and ion losses in the ion-molecule reaction drift tube. A mass spectrometric voltage scanning procedure elucidates the relative binding energies of the ion adducts, which influence the transmission efficiency of molecular ions through the electric fields within the vacuum chamber. Together, this information provides a critical constraint on the sensitivity of a ToF-CIMS towards a wide suite of routinely detected multifunctional organic molecules for which no calibration standards exist. We describe the scanning procedure and collision limit determination, and we show results from the application of these constraints to the measurement of organic aerosol composition at two different field locations.

  9. Radiation-sensitive indicator based on radiation-chemical formation of acids in polyvinyl butyral films containing chloral hydrate

    Science.gov (United States)

    Abdel-Fattah, Atef A.; El-Kelany, M.

    1998-03-01

    Radiation-sensitive indicators based on dyed polyvinyl butyral (PVB) containing acid-sensitive dye (bromophenol blue, BPB) and chloral hydrate (CCl 3CH(OH) 2, 2,2,2-trichloroethane-1, 1-diol) have been developed. These plastic film dosimeters undergo colour change from blue (the alkaline form of BPB) to yellow (the acidic form of BPB), indicating acid formation. The concentration of radiation-formed acids in the films containing different concentrations of chloral hydrate was calculated at different doses. The kinetics of the acid-formation reaction is discussed, indicating a half-order reaction with respect to chloral hydrate concentration. These films can be used as dosimeters for food irradiation applications where the maxima of the useful dose ranges are between 1 and 4 kGy depending on chloral hydrate concentration in the film. The response of these films depends on temperature during irradiation; therefore a correction should be applied. These films have the advantage of negligible humidity effects on response in the intermediate range of relative humidity from 10 to 70% as well as good post-irradiation stability when stored in the dark at room temperature.

  10. Characterization of porcine skin as a model for human skin studies using infrared spectroscopic imaging.

    Science.gov (United States)

    Kong, Rong; Bhargava, Rohit

    2011-06-07

    Porcine skin is often considered a substitute for human skin based on morphological and functional data, for example, for transdermal drug diffusion studies. A chemical, structural and temporal characterization of porcine skin in comparison to human skin is not available but will likely improve our understanding of this porcine skin model. Here, we employ Fourier transform infrared (FT-IR) spectroscopic imaging to holistically measure chemical species as well as spatial structure as a function of time to characterize porcine skin as a model for human skin. Porcine skin was found to resemble human skin spectroscopically and differences are elucidated. Cryo-prepared fresh porcine skin samples for spectroscopic imaging were found to be stable over time and small variations are observed. Hence, we extended characterization to the use of this model for dynamic processes. In particular, the capacity and stability of this model in transdermal diffusion is examined. The results indicate that porcine skin is likely to be an attractive tool for studying diffusion dynamics of materials in human skin.

  11. Skin cancer in skin of color: an update on current facts, trends, and misconceptions.

    Science.gov (United States)

    Battie, Claire; Gohara, Mona; Verschoore, Michèle; Roberts, Wendy

    2013-02-01

    For many fair-skinned individuals around the world, skin cancer is the leading malignancy. Although skin cancer comprises only 1% to 2% of all malignancies in those with darker complexions, the mortality rates in this subgroup are substantially higher when compared with their Caucasian counterparts. This discrepancy is largely as a result of delayed detection/treatment, and a false perception among patient and physician that brown skin confers complete protection against skin cancer. Recent studies show that 65% of surveyed African Americans never wore sunscreen, despite living in sunny climates, and that more than 60% of minority respondents erroneously believed that they were not at risk for skin cancer. Dark skin offers some protection from ultraviolet (UV) light. However, there is considerable heterogeneity in skin of color, a phenomenon that is accentuated by mixed heritage. Ethnicity does not confer skin type anymore. People of color do experience sunburn, and from a biological point of view, all skin types appear to be sensitive to UV-induced DNA damage, with an inverse relationship between skin color and sensitivity to UV light. Our population is changing rapidly, and within the next few decades minority populations will become the majority. It is therefore imperative to educate both physicians and patients on the perceived immunity against cutaneous malignancies, the need for sun protection, and the clinical signs of skin cancer in non-Caucasian people, so that future unnecessary mortality can be avoided.

  12. Modelling the exposure to chemicals for risk assessment: a comprehensive library of multimedia and PBPK models for integration, prediction, uncertainty and sensitivity analysis - the MERLIN-Expo tool.

    Science.gov (United States)

    Ciffroy, P; Alfonso, B; Altenpohl, A; Banjac, Z; Bierkens, J; Brochot, C; Critto, A; De Wilde, T; Fait, G; Fierens, T; Garratt, J; Giubilato, E; Grange, E; Johansson, E; Radomyski, A; Reschwann, K; Suciu, N; Tanaka, T; Tediosi, A; Van Holderbeke, M; Verdonck, F

    2016-10-15

    MERLIN-Expo is a library of models that was developed in the frame of the FP7 EU project 4FUN in order to provide an integrated assessment tool for state-of-the-art exposure assessment for environment, biota and humans, allowing the detection of scientific uncertainties at each step of the exposure process. This paper describes the main features of the MERLIN-Expo tool. The main challenges in exposure modelling that MERLIN-Expo has tackled are: (i) the integration of multimedia (MM) models simulating the fate of chemicals in environmental media, and of physiologically based pharmacokinetic (PBPK) models simulating the fate of chemicals in human body. MERLIN-Expo thus allows the determination of internal effective chemical concentrations; (ii) the incorporation of a set of functionalities for uncertainty/sensitivity analysis, from screening to variance-based approaches. The availability of such tools for uncertainty and sensitivity analysis aimed to facilitate the incorporation of such issues in future decision making; (iii) the integration of human and wildlife biota targets with common fate modelling in the environment. MERLIN-Expo is composed of a library of fate models dedicated to non biological receptor media (surface waters, soils, outdoor air), biological media of concern for humans (several cultivated crops, mammals, milk, fish), as well as wildlife biota (primary producers in rivers, invertebrates, fish) and humans. These models can be linked together to create flexible scenarios relevant for both human and wildlife biota exposure. Standardized documentation for each model and training material were prepared to support an accurate use of the tool by end-users. One of the objectives of the 4FUN project was also to increase the confidence in the applicability of the MERLIN-Expo tool through targeted realistic case studies. In particular, we aimed at demonstrating the feasibility of building complex realistic exposure scenarios and the accuracy of the

  13. High performance PbS quantum dot sensitized solar cells via electric field assisted in situ chemical deposition on modulated TiO2 nanotube arrays.

    Science.gov (United States)

    Tao, Liang; Xiong, Yan; Liu, Hong; Shen, Wenzhong

    2014-01-21

    Quantum dot sensitized solar cells (QDSSCs) are attractive photovoltaic devices due to their simplicity and low material requirements. However, efforts to realize high efficiencies in QDSSCs have often been offset by complicated processes and expensive or toxic materials, significantly limiting their useful application. In this work, we have realized for the first time, high performance PbS QDSSCs based on TiO2 nanotube arrays (NTAs) via an in situ chemical deposition method controlled by a low electric field. An efficiency, η, of ~3.41% under full sun illumination has been achieved, which is 133.6% higher than the best result previously reported for a simple system without doping or co-sensitizing, and comparable to systems with additional chemicals. Furthermore, a high open-circuit voltage (0.64 V), short-circuit current (8.48 mA cm(-2)) and fill factor (0.63) have been achieved. A great increase in the quantity of the loaded quantum dots (QDs) in the NTAs was obtained from the in situ electric field assisted chemical bath deposition (EACBD) process, which was the most significant contributing factor with respect to the high JSC. The high VOC and FF have been attributed to a much shorter electron path, less structural and electronic defects, and lower recombination in the ordered TiO2 NTAs produced by oscillating anodic voltage. Besides, the optimal film thickness (~4 μm) based on the NTAs was much thinner than that of the control cell based on nanoporous film (~30.0 μm). This investigation can hopefully offer an effective way of realizing high performance QDSSCs and QD growth/installation in other nanostructures as well.

  14. Evaluation on the capability of a skin decontaminatant PF2009 to inactivate chemical warfare agents%皮肤洗消剂PF2009对化学毒剂的消毒作用

    Institute of Scientific and Technical Information of China (English)

    刘红岩; 刘艳芹; 应莺; 林京玉; 王伊文; 左国民; 朱海燕; 钟玉绪

    2011-01-01

    Objective To evaluate the capability of skin decontamination lotion PF2009 to decontaminate chemical warfare agents. Methods The remnant of chemical warfare agents, soman (GD), VX or sulfur mustard(HD), was measured with gas phase chromatography or T-135 method after being mixed with PF2009 for indicated time. The mixtures of PF2009 with GD, VX at a molar ratio of 10:1 was measured by the main agent were administered to rabbits through intraperitoneal injection. 6 days later, the activity of acetylcholinesterase(AChE) in animal blood was determined with the method of DTNB. The survival rate was calculated after counting the living and died rabbits. The mixtures of PF2009 with HD were administered to rabbit skin. The area of injured skin was measured. Histochemical method was employed to observe the pathological change in the injured skin. Results Remnant of GD or VX could not be detected after being mixed with PF2009 at a volume ratio of 150 for 10 min. Under the same mixing condition, decontaminated HD increased from 80% to 94% when prolonging the incubation time from 10 to 60 min. Rabbits were intraperitoneally administered with the mixture of PF2009 with GD at a dose of 454 or 9.00 mg/kg or VX at a dose 3.34 mg/kg. No animals died in PF2009 group. In contrast, all rabbits died in lotion matrix control group during the 6 days' observation. 90% activity of AChE in blood was maintained for PF2009 group when compared with that for un-administered normal animals. The mixture of PF2009 with HD was administered to the rabbit skin at a dose of 1 mg/ cm2. The damage of skin was much lighter in PF2009 group than in lotion matrix control group when being evaluated with the area value of injured skin and histochemical staining. Conclusion The skin decontamination lotion PF2009 is effective in inactivating chemical warfare agents in vitro.%目的 通过检测皮肤洗消剂PF2009对化学毒剂的体外消毒效率,对皮肤洗消剂PF2009的消毒效果进行评价.方法

  15. Reduction of Large Detailed Chemical Kinetic Mechanisms for Autoignition Using Joint Analyses of Reaction Rates and Sensitivities

    Energy Technology Data Exchange (ETDEWEB)

    Saylam, A; Ribaucour, M; Pitz, W J; Minetti, R

    2006-11-29

    A new technique of reduction of detailed mechanisms for autoignition, which is based on two analysis methods is described. An analysis of reaction rates is coupled to an analysis of reaction sensitivity for the detection of redundant reactions. Thresholds associated with the two analyses have a great influence on the size and efficiency of the reduced mechanism. Rules of selection of the thresholds are defined. The reduction technique has been successfully applied to detailed autoignition mechanisms of two reference hydrocarbons: n-heptane and iso-octane. The efficiency of the technique and the ability of the reduced mechanisms to reproduce well the results generated by the full mechanism are discussed. A speedup of calculations by a factor of 5.9 for n-heptane mechanism and by a factor of 16.7 for iso-octane mechanism is obtained without losing accuracy of the prediction of autoignition delay times and concentrations of intermediate species.

  16. Chemical synthesis of CdS onto TiO2 nanorods for quantum dot sensitized solar cells

    Science.gov (United States)

    Pawar, Sachin A.; Patil, Dipali S.; Lokhande, Abhishek C.; Gang, Myeng Gil; Shin, Jae Cheol; Patil, Pramod S.; Kim, Jin Hyeok

    2016-08-01

    A quantum dot sensitized solar cell (QDSSC) is fabricated using hydrothermally grown TiO2 nanorods and successive ionic layer adsorption and reaction (SILAR) deposited CdS. Surface morphology of the TiO2 films coated with different SILAR cycles of CdS is examined by Scanning Electron Microscopy which revealed aggregated CdS QDs coverage grow on increasing onto the TiO2 nanorods with respect to cycle number. Under AM 1.5G illumination, we found the TiO2/CdS QDSSC photoelectrode shows a power conversion efficiency of 1.75%, in an aqueous polysulfide electrolyte with short-circuit photocurrent density of 4.04 mA/cm2 which is higher than that of a bare TiO2 nanorods array.

  17. Chemical and structural analysis of solvothermal synthesized tungsten oxide nanotube without template and its hydrogen sensitive property

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Taisheng; Zhang, Yue, E-mail: zhangy@buaa.edu.cn; Li, Chen

    2014-01-25

    Graphical abstract: Imaged models of formation of nanotube during crystal growth: (a) precursor react with each other; (b) the crystal plane bended as crystallization; (c) the nanotube formed finally. Highlights: • The WO{sub 3} naonotube was prepared by solvothermal method without any addition. • The steric effect and the nucleation and growth mechanism resulted in the nanotube. • The nanotube film surface showed high oxygen vacancies. • The nanotube film showed diffusion dominated sensitivity. -- Abstract: Tungsten oxide nanotubes were synthesized by solvothermal process without template. The steric effect and the concentration of WCl{sub 6} are the dominant factors for the formation mechanism of the nanotube. The steric effect was experimentally and systematically studied with solvents including ethanol, isopropanol, n-propanol and butylalcohol, which have different molecular configuration and length, while the effect of concentration was investigated by characterizing the nanostructured productions. The samples have been investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The surface chemistry of the nanotube is characterized by X-ray photoelectron spectroscopy (XPS). The results indicated that the solvents species and WCl{sub 6} concentration obviously diversified the morphologies of the products; the nanotubes synthesized with isopropanol composed of W{sub 18}O{sub 49} phase; the crystal defects (O atom vacancy) formed during rapid crystallization could be modified by heat treatment. The DC electrical response of the nanotube thin film to hydrogen was measured the temperature range from 200 °C to 300 °C, which indicated a decline in electrical resistance with good sensitivity, and showed the mechanism that the reaction limited process works at low temperature, whereas the diffusion limited process works at higher temperature.

  18. Skin Keratins.

    Science.gov (United States)

    Wang, Fengrong; Zieman, Abigail; Coulombe, Pierre A

    2016-01-01

    Keratins comprise the type I and type II intermediate filament-forming proteins and occur primarily in epithelial cells. They are encoded by 54 evolutionarily conserved genes (28 type I, 26 type II) and regulated in a pairwise and tissue type-, differentiation-, and context-dependent manner. Keratins serve multiple homeostatic and stress-enhanced mechanical and nonmechanical functions in epithelia, including the maintenance of cellular integrity, regulation of cell growth and migration, and protection from apoptosis. These functions are tightly regulated by posttranslational modifications as well as keratin-associated proteins. Genetically determined alterations in keratin-coding sequences underlie highly penetrant and rare disorders whose pathophysiology reflects cell fragility and/or altered tissue homeostasis. Moreover, keratin mutation or misregulation represents risk factors or genetic modifiers for several acute and chronic diseases. This chapter focuses on keratins that are expressed in skin epithelia, and details a number of basic protocols and assays that have proven useful for analyses being carried out in skin.

  19. Filaggrin and Skin Barrier Function.

    Science.gov (United States)

    Kezic, Sanja; Jakasa, Ivone

    2016-01-01

    The skin barrier function is greatly dependent on the structure and composition of the uppermost layer of the epidermis, the stratum corneum (SC), which is made up of flattened anucleated cells surrounded by highly organized and continuous lipid matrix. The interior of the corneocytes consists mainly of keratin filaments aggregated by filaggrin (FLG) protein. Next, together with several other proteins, FLG is cross-linked into a mechanically robust cornified cell envelope providing a scaffold for the extracellular lipid matrix. In addition to its role for the SC structural and mechanical integrity, FLG degradation products account in part for the water-holding capacity and maintenance of acidic pH of the SC, both crucial for the epidermal barrier homoeostasis by regulating activity of multiple enzymes that control desquamation, lipid synthesis and inflammation. The major determinant of FLG expression in the skin are loss-of-function mutations in FLG, the strongest genetic risk factor for atopic dermatitis (AD), an inflammatory skin disease characterized by a reduced skin barrier function. The prevalence of FLG mutations varies greatly among different populations and ranges from about 10% in Northern Europeans to less than 1% in the African populations. An impaired skin barrier facilitates absorption of potentially hazardous chemicals, which might cause adverse effects in the skin, such as contact dermatitis, or systemic toxicity after their passage into blood. In another direction, a leaky epidermal barrier will lead to enhanced loss of water from the skin. A recent study has shown that even subtle increase in epidermal water loss in newborns increases the risk for AD. Although there are multiple modes of action by which FLG might affect skin barrier it is still unclear whether and how FLG deficiency leads to the reduced skin barrier function. This chapter summarizes the current knowledge in this field obtained from clinical studies, and animal and in vitro models

  20. Linkages between the life-history evolution of tropical and temperate birds and the resistance of cultured skin fibroblasts to oxidative and non-oxidative chemical injury

    OpenAIRE

    Jimenez, Ana Gabriela; Harper, James M.; Simon A. Queenborough; Williams, Joseph B.

    2013-01-01

    A fundamental challenge facing physiological ecologists is to understand how variation in life history at the whole-organism level might be linked to cellular function. Thus, because tropical birds have higher annual survival and lower rates of metabolism, we hypothesized that cells from tropical species would have greater cellular resistance to chemical injury than cells from temperate species. We cultured dermal fibroblasts from 26 tropical and 26 temperate species of birds and examined cel...

  1. Evidence that radio-sensitive cells are central to skin-phase protective immunity in CBA/Ca mice vaccinated with radiation-attenuated cercariae of Schistosoma mansoni as well as in naive mice protected with vaccine serum

    Energy Technology Data Exchange (ETDEWEB)

    Delgado, V.S.; McLaren, D.J. (National Inst. for Medical Research, London (UK))

    1990-02-01

    Naive CBA/Ca mice and CBA/ca mice vaccinated 4 weeks previously with radiation-attenuated cercariae of Schistosoma mansoni were subjected to 550 rad of whole body (gamma) irradiation and then challenged 3 days later with normal cercariae. The perfusion recovery data showed that this procedure reduced the primary worm burden in naive mice by 22% and the challence worm burden in vaccinated mice by 82%. Irradiation also ablated the peripheral blood leucocytes of both mouse groups by 90-100% at the time of challenge. Histological data revealed that such treatment caused a dramatic change in number, size and leucocyte composition of cutaneous inflammatory skin reactions that characterize challenged vacccinated mice and are known to entrap invading larvae; cutaneous eosinophils were preferentially abolished by this treatment. Polyvaccine mouse serum that conferred protection passively upon naive recipient mice, failed to protect naive/irradiated mice when administered by the same protocol. Distraction of macrophages by treatment of mice with silica did not affect the establishment of a primary worm burden and reduced the protection exhibited by vaccinated mice by only 16%. These data indicade that radio-sensitive cells are important to both innate and specific acquired resistance in this mouse model and that macrophages contribute only marginally to the expression of vaccine immunity. (author).

  2. Triclosan Induces Thymic Stromal Lymphopoietin in Skin Promoting Th2 Allergic Responses.

    Science.gov (United States)

    Marshall, Nikki B; Lukomska, Ewa; Long, Carrie M; Kashon, Michael L; Sharpnack, Douglas D; Nayak, Ajay P; Anderson, Katie L; Jean Meade, B; Anderson, Stacey E

    2015-09-01

    Triclosan is an antimicrobial chemical incorporated into many personal, medical and household products. Approximately, 75% of the U.S. population has detectable levels of triclosan in their urine, and although it is not typically considered a contact sensitizer, recent studies have begun to link triclosan exposure with augmented allergic disease. We examined the effects of dermal triclosan exposure on the skin and lymph nodes of mice and in a human skin model to identify mechanisms for augmenting allergic responses. Triclosan (0%-3%) was applied topically at 24-h intervals to the ear pinnae of OVA-sensitized BALB/c mice. Skin and draining lymph nodes were evaluated for cellular responses and cytokine expression over time. The effects of triclosan (0%-0.75%) on cytokine expression in a human skin tissue model were also examined. Exposure to triclosan increased the expression of TSLP, IL-1β, and TNF-α in the skin with concomitant decreases in IL-25, IL-33, and IL-1α. Similar changes in TSLP, IL1B, and IL33 expression occurred in human skin. Topical application of triclosan also increased draining lymph node cellularity consisting of activated CD86(+)GL-7(+) B cells, CD80(+)CD86(+) dendritic cells, GATA-3(+)OX-40(+)IL-4(+)IL-13(+) Th2 cells and IL-17 A(+) CD4 T cells. In vivo antibody blockade of TSLP reduced skin irritation, IL-1β expression, lymph node cellularity, and Th2 responses augmented by triclosan. Repeated dermal exposure to triclosan induces TSLP expression in skin tissue as a potential mechanism for augmenting allergic responses.

  3. Fluorescence Ratiometric Assay Strategy for Chemical Transmitter of Living Cells Using H2O2-Sensitive Conjugated Polymers.

    Science.gov (United States)

    Wang, Yunxia; Li, Shengliang; Feng, Liheng; Nie, Chenyao; Liu, Libing; Lv, Fengting; Wang, Shu

    2015-11-01

    A new water-soluble conjugated poly(fluorene-co-phenylene) derivative (PFP-FB) modified with boronate-protected fluorescein (peroxyfluor-1) via PEG linker has been designed and synthesized. In the presence of H2O2, the peroxyfluor-1 group can transform into green fluorescent fluorescein by deprotecting the boronate protecting groups. In this case, upon selective excitation of PFP-FB backbone at 380 nm, efficient fluorescence resonance energy transfer (FRET) from PFP-FB backbone to fluorescein occurs, and accordingly, the fluorescence color of PFP-FB changes from blue to green. Furthermore, the emission color of PFP-FB and the FRET ratio change in a concentration-dependent manner. By taking advantage of PFP-FB, ratiometric detection of choline and acetylcholine (ACh) through cascade enzymatic reactions and further dynamic monitoring of the choline consumption process of cancer cells have been successfully realized. Thus, this new polymer probe promotes the development of enzymatic biosensors and provides a simpler and more effective way for detecting the chemical transmitter of living cells.

  4. Modeling and experiment of dye-sensitized solar cell with vertically aligned ZnO nanorods through chemical bath deposition

    Science.gov (United States)

    Wahyuono, Ruri Agung; Risanti, Doty D.

    2015-01-01

    A theoretical model based on electron diffusion differential equation and Schottky barrier model was developed to determine the current-voltage characteristics of DSSC. To verify the model DSSC with ZnO nanorods photoelectrode which was chemically bath deposited onto the TCO was fabricated. According to modeling results, increasing of recombination current density J at these interfaces results in a decrease in Schottky barrier height φb and therefore improves the photovoltage under the open-circuit condition. It is found that the open-circuit voltage remains constant when the TCO/ZnO Schottky barrier height was varied in the range of 0.45 - 0.6 eV. This theoretical model consistents with the experimental result in which the fabricated DSSCs can produce conversion efficiency in the range of 0.98 - 1.16%. The trend in photovoltage calculated in the theoretical model basically agrees with the experimental result, although the calculated photocurrent is somewhat over estimated compared to the experimental results. The model presents that the ideality factor for ZnO nanorods, which also contributes to the enhancement of photovoltage, increases in the range of 2.75 - 3.0 as the annealing temperature is increased in the experiment.

  5. A preliminary study of skin ultrasound in diffuse cutaneous systemic sclerosis: Does skin echogenicity matter?

    Science.gov (United States)

    Xu, Dong; Wang, Liang; Li, Jian-chu; Jiang, Yu-xin; Wang, Qian; Li, Meng-tao; Zhang, Feng-chun; Zeng, Xiao-feng

    2017-01-01

    Objective To evaluate the usefulness of skin ultrasound and acoustic radiation force impulse (ARFI) quantification in diffuse cutaneous systemic sclerosis (dcSSc). Patients and methods 28 patients with dcSSc, and 15 age gender matched normal controls were recruited. Skin echogenicity, thickness, and ARFI quantification were measured by ultrasound at 17 sites corresponding to the modified Rodnan skin score (mRSS) in each participant. Compared with controls, skin echogenicity of dcSSc patients was classified into isoechoic, hypoechoic, and hyperechoic. The skin thickness, ARFI quantification and mRSS were compared between isoechoic, hypoechoic, hyperechoic and controls. Results In patients with dcSSc, the skin thickness increased as the echogenicity changed on the order of isoechoic, hypoechoic and hyperechoic. ARFI quantification was significantly higher in hyperechoic than isoechoic (p<0.001). The mRSS were significantly higher in hyperechoic and/or hypoechoic than isoechoic. For isoechoic patients and healthy controls, the skin echogenicity or thickness was no significant different, however, the ARFI quantification was significantly higher in isoechoic than controls. Conclusion Skin ultrasound is feasible for assessing the skin involvement in dcSSc. Skin echogenicity correlates with skin thickness, stiffness, and mRSS. ARFI quantification may be more sensitive to detect skin changes, compared with skin echogenicity and thickness. PMID:28339492

  6. The LINA Study: Higher Sensitivity of Infant Compared to Maternal Eosinophil/Basophil Progenitors to Indoor Chemical Exposures

    Directory of Open Access Journals (Sweden)

    Friederike Hörnig

    2016-01-01

    Full Text Available Purpose. Enhanced eosinophil/basophil (Eo/B progenitor cell levels are known to be associated with allergic inflammation and atopy risk. The aim of the present study was to investigate the influence of different indoor exposures on the recruitment and differentiation of Eo/B progenitors in mother-child pairs. Methods. In 68 mother-child pairs of the LINA study peripheral blood mononuclear cells were used to assess Eo/B colony forming units (CFUs. Information about disease outcomes and indoor exposures was obtained from questionnaires. Indoor concentrations of volatile organic compounds (VOCs were measured by passive sampling. Results. Infant’s Eo/B CFUs were positively associated with exposure to tobacco smoke, disinfectants, or VOCs. In contrast, for maternal Eo/B CFUs, only a few associations were seen. Higher numbers of infant Eo/B CFUs were observed in children with wheezing symptoms within the second year of life. Conclusions. We demonstrate that infant’s hematopoietic cells seem to respond with more sensitivity to environmental exposure compared to maternal cells. At least in infants, an activation of these hematopoietic cells by environmental exposure could contribute to an enhanced risk for the development of respiratory outcomes.

  7. Sensitivity of chemistry-transport model simulations to the duration of chemical and transport operators: a case study with GEOS-Chem v10-01

    Science.gov (United States)

    Philip, Sajeev; Martin, Randall V.; Keller, Christoph A.

    2016-05-01

    Chemistry-transport models involve considerable computational expense. Fine temporal resolution offers accuracy at the expense of computation time. Assessment is needed of the sensitivity of simulation accuracy to the duration of chemical and transport operators. We conduct a series of simulations with the GEOS-Chem chemistry-transport model at different temporal and spatial resolutions to examine the sensitivity of simulated atmospheric composition to operator duration. Subsequently, we compare the species simulated with operator durations from 10 to 60 min as typically used by global chemistry-transport models, and identify the operator durations that optimize both computational expense and simulation accuracy. We find that longer continuous transport operator duration increases concentrations of emitted species such as nitrogen oxides and carbon monoxide since a more homogeneous distribution reduces loss through chemical reactions and dry deposition. The increased concentrations of ozone precursors increase ozone production with longer transport operator duration. Longer chemical operator duration decreases sulfate and ammonium but increases nitrate due to feedbacks with in-cloud sulfur dioxide oxidation and aerosol thermodynamics. The simulation duration decreases by up to a factor of 5 from fine (5 min) to coarse (60 min) operator duration. We assess the change in simulation accuracy with resolution by comparing the root mean square difference in ground-level concentrations of nitrogen oxides, secondary inorganic aerosols, ozone and carbon monoxide with a finer temporal or spatial resolution taken as "truth". Relative simulation error for these species increases by more than a factor of 5 from the shortest (5 min) to longest (60 min) operator duration. Chemical operator duration twice that of the transport operator duration offers more simulation accuracy per unit computation. However, the relative simulation error from coarser spatial resolution generally

  8. Different pH-sensitivity patterns of 30 sodium channel inhibitors suggest chemically different pools along the access pathway

    Science.gov (United States)

    Lazar, Alexandra; Lenkey, Nora; Pesti, Krisztina; Fodor, Laszlo; Mike, Arpad

    2015-01-01

    The major drug binding site of sodium channels is inaccessible from the extracellular side, drug molecules can only access it either from the membrane phase, or from the intracellular aqueous phase. For this reason, ligand-membrane interactions are as important determinants of inhibitor properties, as ligand-protein interactions. One-way to probe this is to modify the pH of the extracellular fluid, which alters the ratio of charged vs. uncharged forms of some compounds, thereby changing their interaction with the membrane. In this electrophysiology study we used three different pH values: 6.0, 7.3, and 8.6 to test the significance of the protonation-deprotonation equilibrium in drug access and affinity. We investigated drugs of several different indications: carbamazepine, lamotrigine, phenytoin, lidocaine, bupivacaine, mexiletine, flecainide, ranolazine, riluzole, memantine, ritanserin, tolperisone, silperisone, ambroxol, haloperidol, chlorpromazine, clozapine, fluoxetine, sertraline, paroxetine, amitriptyline, imipramine, desipramine, maprotiline, nisoxetine, mianserin, mirtazapine, venlafaxine, nefazodone, and trazodone. We recorded the pH-dependence of potency, reversibility, as well as onset/offset kinetics. As expected, we observed a strong correlation between the acidic dissociation constant (pKa) of drugs and the pH-dependence of their potency. Unexpectedly, however, the pH-dependence of reversibility or kinetics showed diverse patterns, not simple correlation. Our data are best explained by a model where drug molecules can be trapped in at least two chemically different environments: A hydrophilic trap (which may be the aqueous cavity within the inner vestibule), which favors polar and less lipophilic compounds, and a lipophilic trap (which may be the membrane phase itself, and/or lipophilic binding sites on the channel). Rescue from the hydrophilic and lipophilic traps can be promoted by alkalic and acidic extracellular pH, respectively. PMID:26441665

  9. Different pH-sensitivity patterns of 30 sodium channel inhibitors suggest chemically different pools along the access pathway.

    Directory of Open Access Journals (Sweden)

    Alexandra eLazar

    2015-09-01

    Full Text Available The major drug binding site of sodium channels is inaccessible from the extracellular side, drug molecules can only access it either from the membrane phase, or from the intracellular aqueous phase. For this reason, ligand-membrane interactions are as important determinants of inhibitor properties, as ligand-protein interactions. One way to probe this is to modify the pH of the extracellular fluid, which alters the ratio of charged vs. uncharged forms of some compounds, thereby changing their interaction with the membrane. In this electrophysiology study we used three different pH values: 6.0, 7.3 and 8.6 to test the significance of the protonation-deprotonation equilibrium in drug access and affinity. We investigated drugs of several different indications: carbamazepine, lamotrigine, phenytoin, lidocaine, bupivacaine, mexiletine, flecainide, ranolazine, riluzole, memantine, ritanserin, tolperisone, silperisone, ambroxol, haloperidol, chlorpromazine, clozapine, fluoxetine, sertraline, paroxetine, amitriptyline, imipramine, desipramine, maprotiline, nisoxetine, mianserin, mirtazapine, venlafaxine, nefazodone and trazodone. We recorded the pH-dependence of potency, reversibility, as well as onset/offset kinetics. As expected, we observed a strong correlation between the acidic dissociation constant (pKa of drugs and the pH-dependence of their potency. Unexpectedly, however, the pH-dependence of reversibility or kinetics showed diverse patterns, not simple correlation. Our data are best explained by a model where drug molecules can be trapped in at least two chemically different environments: A hydrophilic trap (which may be the aqueous cavity within the inner vestibule, which favors polar and less lipophilic compounds, and a lipophilic trap (which may be the membrane phase itself, and/or lipophilic binding sites on the channel. Rescue from the hydrophilic and lipophilic traps can be promoted by alkalic and acidic extracellular pH, respectively.

  10. Template-free TiO2 photoanodes for dye-sensitized solar cell via modified chemical route.

    Science.gov (United States)

    Gaikwad, M A; Mane, A A; Desai, S P; Moholkar, A V

    2017-02-15

    Surfactant and template-free Titanium dioxide (TiO2) spheres have been deposited via ultrasonic rinsing assisted modified successive ionic layer adsorption and reaction (M-SILAR) method. The effect of M-SILAR cycle variation on the growth of TiO2 films and power conversion efficiency (PCE) of dye-sensitized solar cells (DSSCs) has been reported. Also, the significant influence of the dye adsorption time of photoelectrodes on the overall PCE of TiO2 based DSSCs has been investigated systematically. The SEM images reveal that the TiO2 microspheres are made up of densely packed and interconnected nanospheres. After dye loading maximum absorption peak around 500nm is seen with broader coverage in the visible region of the solar spectrum. The excess amount of dye for dye loading time 15h did not contribute to current and is suspected to be present either in multilayers or physisorbed on the surface of TiO2. The DSSC prepared using photoelectrode TO125 and dye loading time of 12h exhibited the highest power conversion efficiency (PCE) of 1.16% with short-circuit current density (Jsc) of 8.17mA/cm(2), open circuit voltage (Voc) of 0.42V and fill factor of 0.34. The PCE is attributed to the large molecular interconnected TiO2 spheres diffusing visible light to enhance the light absorption. Also, it possesses relatively superior 3-D microsphere like structure and thus provides the effective pathway to the photogenerated electrons with low recombination rate, leading to attaining the high PCE.

  11. Pickering emulsions for skin decontamination.

    Science.gov (United States)

    Salerno, Alicia; Bolzinger, Marie-Alexandrine; Rolland, Pauline; Chevalier, Yves; Josse, Denis; Briançon, Stéphanie

    2016-08-01

    This study aimed at developing innovative systems for skin decontamination. Pickering emulsions, i.e. solid-stabilized emulsions, containing silica (S-PE) or Fuller's earth (FE-PE) were formulated. Their efficiency for skin decontamination was evaluated, in vitro, 45min after an exposure to VX, one of the most highly toxic chemical warfare agents. Pickering emulsions were compared to FE (FE-W) and silica (S-W) aqueous suspensions. PE containing an oil with a similar hydrophobicity to VX should promote its extraction. All the formulations reduced significantly the amount of VX quantified on and into the skin compared to the control. Wiping the skin surface with a pad already allowed removing more than half of VX. FE-W was the less efficient (85% of VX removed). The other formulations (FE-PE, S-PE and S-W) resulted in more than 90% of the quantity of VX removed. The charge of particles was the most influential factor. The low pH of formulations containing silica favored electrostatic interactions of VX with particles explaining the better elimination from the skin surface. Formulations containing FE had basic pH, and weak interactions with VX did not improve the skin decontamination. However, these low interactions between VX and FE promote the transfer of VX into the oil droplets in the FE-PE.

  12. Chemically grown vertically aligned 1D ZnO nanorods with CdS coating for efficient quantum dot sensitized solar cells (QDSSC): a controlled synthesis route.

    Science.gov (United States)

    Mali, Sawanta S; Kim, Hyungjin; Patil, Pramod S; Hong, Chang Kook

    2013-12-28

    In the present article, vertically aligned ZnO nanorod arrays were synthesized by an aqueous chemical growth (ACG) route on a fluoride doped tin oxide (FTO) coated glass substrate. These nanorods were further sensitized with cadmium sulfide (CdS) quantum dots (QDs) by a successive ionic layer adsorption and reaction (SILAR) technique. The synthesized CdS coated ZnO nanorods were characterized for their structural and morphological properties with X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and field emission scanning electron microscopy (FESEM). Finally, prepared CdS coated 1D ZnO photoelectrodes were tested for their photoelectrochemical performance. Our results show that the sample deposited after 40 SILAR cycles shows 5.61 mA cm(-2) short current density (JSC) with η = 1.61% power conversion efficiency.

  13. Pharmaceutical effect of contraceptive pills on the skin.

    Science.gov (United States)

    Foldes, E G

    1988-07-01

    Described are the various effects of birth control methods on the skin-mainly those of the contraceptive pill. The equilibrium of healthy skins and mucosa might be affected by these chemicals or pharmaceutical agents, causing different manifestations. The skin and mucosa should be looked upon as integral parts of the human body and its functions even where localized symptoms arise.

  14. How to improve skin notation

    DEFF Research Database (Denmark)

    Sartorelli, Pietro; Ahlers, Heinz W.; Alanko, Kristiina

    2007-01-01

    The ICOH Scientific Committee on Occupational and Environmental Dermatoses organized an International Workshop on “Dermal risk assessment at workplace” with the aim of focussing on the different ways of approaching the concept of skin notation (S) for chemicals. The Workshop participants presented...... their ideas on several aspects of S such as the problems related to the absorption through the compromised skin, the different approaches to S and models that can be used as alternatives to S. Participants agreed to produce a position paper with the goal of exploring the actions needed to improve the S system...

  15. Penetration through the Skin Barrier

    DEFF Research Database (Denmark)

    Nielsen, Jesper Bo; Benfeldt, Eva; Holmgaard, Rikke

    2016-01-01

    The skin is a strong and flexible organ with barrier properties essential for maintaining homeostasis and thereby human life. Characterizing this barrier is the ability to prevent some chemicals from crossing the barrier while allowing others, including medicinal products, to pass at varying rates......-through diffusion cells) as well as in vivo methods (microdialysis and microperfusion). Then follows a discussion with examples of how different characteristics of the skin (age, site and integrity) and of the penetrants (size, solubility, ionization, logPow and vehicles) affect the kinetics of percutaneous...

  16. Mouse Prkar1a haploinsufficiency leads to an increase in tumors in the Trp53+/− or Rb1+/− backgrounds and chemically induced skin papillomas by dysregulation of the cell cycle and Wnt signaling

    Science.gov (United States)

    Almeida, Madson Q.; Muchow, Michael; Boikos, Sosipatros; Bauer, Andrew J.; Griffin, Kurt J.; Tsang, Kit Man; Cheadle, Chris; Watkins, Tonya; Wen, Feng; Starost, Matthew F.; Bossis, Ioannis; Nesterova, Maria; Stratakis, Constantine A.

    2010-01-01

    PRKAR1A inactivation leads to dysregulated cAMP signaling and Carney complex (CNC) in humans, a syndrome associated with skin, endocrine and other tumors. The CNC phenotype is not easily explained by the ubiquitous cAMP signaling defect; furthermore, Prkar1a+/− mice did not develop skin and other CNC tumors. To identify whether a Prkar1a defect is truly a generic but weak tumorigenic signal that depends on tissue-specific or other factors, we investigated Prkar1a+/− mice when bred within the Rb1+/− or Trp53+/− backgrounds, or treated with a two-step skin carcinogenesis protocol. Prkar1a+/− Trp53+/− mice developed more sarcomas than Trp53+/− mice (P < 0.05) and Prkar1a+/− Rb1+/− mice grew more (and larger) pituitary and thyroid tumors than Rb1+/− mice. All mice with double heterozygosity had significantly reduced life-spans compared with their single-heterozygous counterparts. Prkar1a+/− mice also developed more papillomas than wild-type animals. A whole-genome transcriptome profiling of tumors produced by all three models identified Wnt signaling as the main pathway activated by abnormal cAMP signaling, along with cell cycle abnormalities; all changes were confirmed by qRT–PCR array and immunohistochemistry. siRNA down-regulation of Ctnnb1, E2f1 or Cdk4 inhibited proliferation of human adrenal cells bearing a PRKAR1A-inactivating mutation and Prkar1a+/− mouse embryonic fibroblasts and arrested both cell lines at the G0/G1 phase of the cell cycle. In conclusion, Prkar1a haploinsufficiency is a relatively weak tumorigenic signal that can act synergistically with other tumor suppressor gene defects or chemicals to induce tumors, mostly through Wnt-signaling activation and cell cycle dysregulation, consistent with studies in human neoplasms carrying PRKAR1A defects. PMID:20080939

  17. TRP Channels in Skin Biology and Pathophysiology

    Science.gov (United States)

    Caterina, Michael J.; Pang, Zixuan

    2016-01-01

    Ion channels of the Transient Receptor Potential (TRP) family mediate the influx of monovalent and/or divalent cations into cells in response to a host of chemical or physical stimuli. In the skin, TRP channels are expressed in many cell types, including keratinocytes, sensory neurons, melanocytes, and immune/inflammatory cells. Within these diverse cell types, TRP channels participate in physiological processes ranging from sensation to skin homeostasis. In addition, there is a growing body of evidence implicating abnormal TRP channel function, as a product of excessive or deficient channel activity, in pathological skin conditions such as chronic pain and itch, dermatitis, vitiligo, alopecia, wound healing, skin carcinogenesis, and skin barrier compromise. These diverse functions, coupled with the fact that many TRP channels possess pharmacologically accessible sites, make this family of proteins appealing therapeutic targets for skin disorders. PMID:27983625

  18. TRP Channels in Skin Biology and Pathophysiology

    Directory of Open Access Journals (Sweden)

    Michael J. Caterina

    2016-12-01

    Full Text Available Ion channels of the Transient Receptor Potential (TRP family mediate the influx of monovalent and/or divalent cations into cells in response to a host of chemical or physical stimuli. In the skin, TRP channels are expressed in many cell types, including keratinocytes, sensory neurons, melanocytes, and immune/inflammatory cells. Within these diverse cell types, TRP channels participate in physiological processes ranging from sensation to skin homeostasis. In addition, there is a growing body of evidence implicating abnormal TRP channel function, as a product of excessive or deficient channel activity, in pathological skin conditions such as chronic pain and itch, dermatitis, vitiligo, alopecia, wound healing, skin carcinogenesis, and skin barrier compromise. These diverse functions, coupled with the fact that many TRP channels possess pharmacologically accessible sites, make this family of proteins appealing therapeutic targets for skin disorders.

  19. Nanocarriers for skin delivery of cosmetic antioxidants

    Directory of Open Access Journals (Sweden)

    Lucia Montenegro

    2014-08-01

    Full Text Available The demand of natural skin care products is steadily growing since consumers perceive them as safe. Currently, cosmetic manufacturers are focusing their efforts on developing innovative natural products to address skin-aging signs, thus meeting consumers’ needs of healthy appearance and well-being. To prevent or treat skin aging, topical supplementation with antioxidant is regarded as one o