72 research outputs found

    The cancer stem cell: Evidence for its origin as an injured autoreactive T Cell

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    This review explores similarities between lymphocytes and cancer cells, and proposes a new model for the genesis of human cancer. We suggest that the development of cancer requires infection(s) during which antigenic determinants from pathogens mimicking self-antigens are co-presented to the immune system, leading to breaking T cell tolerance. Some level of autoimmunity is normal and necessary for effective pathogen eradication. However, autoreactive T cells must be eliminated by apoptosis when the immune response is terminated. Apoptosis can be deficient in the event of a weakened immune system, the causes of which are multifactorial. Some autoreactive T cells suffer genomic damage in this process, but manage to survive. The resulting cancer stem cell still retains some functions of an inflammatory T cell, so it seeks out sites of inflammation inside the body. Due to its defective constitutive production of inflammatory cytokines and other growth factors, a stroma is built at the site of inflammation similar to the temporary stroma built during wound healing. The cancer cells grow inside this stroma, forming a tumor that provides their vascular supply and protects them from cellular immune response. As cancer stem cells have plasticity comparable to normal stem cells, interactions with surrounding normal tissues cause them to give rise to all the various types of cancers, resembling differentiated tissue types. Metastases form at an advanced stage of the disease, with the proliferation of sites of inflammation inside the body following a similar mechanism. Immunosuppressive cancer therapies inadvertently re-invigorate pathogenic microorganisms and parasitic infections common to cancer, leading to a vicious circle of infection, autoimmunity and malignancy that ultimately dooms cancer patients. Based on this new understanding, we recommend a systemic approach to the development of cancer therapies that supports rather than antagonizes the immune system

    Cancer: a single disease with a multitude of manifestions?

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    The relationships of critical nutrients such as plant phenolics, vitamins, minerals and lipids are considered with respect to the incidence of a variety of cancers, and analyzed in terms of how these nutrient deficiencies alter immune function, DNA integrity and cell proliferation. With a significant correlation found between cancer and these nutrient deficiencies, the hypothesis is presented here that nutrition could provide a unifying perception of cancer and recast it as a single disease. This further suggests that a coordinated administration of specific, critical nutrients to cancer patients could lead to the reversal of the disease. It is also proposed that the concurrent presence of a variety of nutritional deficiencies in cancer patients requires a multilevel, systemic approach to this disease as opposed to the single active therapeutic agent approach that is the cornerstone of contemporary research and pharmacology

    Transformation of glucocorticoid and progesterone receptors to the DNA-binding state

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    This brief review explores some recent observations relating to the structure of untransformed glucocorticoid and progesterone receptors and the mechanism by which the receptors are transformed to the DNA-binding state. In their molybdate-stabilized, untransformed state, progesterone and glucocorticoid receptors exist as a heteromeric 8-9S complex containing one unit of steroid binding phosphoprotein and one or two units of the 90 kD heat shock protein hsp90. When the receptors are transformed, the steroid-binding protein dissociates from hsp90. In cytosol preparations, temperature-mediated dissociation proceeds much more rapidly in the presence of hormone. The dissociated receptor binds to DNA with high affinity, regardless of whether it is in the hormone-bound or the hormone-free state. These observations raise the possibility that the primary, and perhaps the only, role for the hormone is to promote dissociation of the receptor-hsp90 complex. Molybdate, vanadate, and tungstate inhibit receptor transformation to the DNA-binding form, an effect that appears to reflect the ability of these transition metal oxyanions to stabilize the complex between the steroid receptor and hsp90. By promoting the formation of disulfide bonds, hydrogen peroxide also stabilizes the glucocorticoid receptor-hsp90 complex and prevents receptor transformation. A small, heat-stable factor present in all cytosol preparations inhibits receptor transformation, and, when the factor is removed, glucocorticoid receptors are rapidly transformed. This ubiquitous factor has the physical properties of a metal anion, and it is proposed that molybdate and vanadate affect steroid receptor complexes by interacting with a metal anion-binding site that is normally occupied by this endogenous receptor-stabilizing factor.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38448/1/240350105_ftp.pd

    Comprehensive overview of the structure and regulation of the glucocorticoid receptor

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    Glucocorticoids are among the most prescribed drugs worldwide for the treatment of numerous immune and inflammatory disorders. They exert their actions by binding to the glucocorticoid receptor (GR), a member of the nuclear receptor superfamily. There are several GR isoforms resulting from alternative RNA splicing and translation initiation of the GR transcript. Additionally, these isoforms are all subject to several transcriptional, post-transcriptional, and post-translational modifications, all of which affect the protein's stability and/or function. In this review, we summarize recent knowledge on the distinct GR isoforms and the processes that generate them. We also review the importance of all known transcriptional, post-transcriptional, and post-translational modifications, including the regulation of GR by microRNAs. Moreover, we discuss the crucial role of the putative GR-bound DNA sequence as an allosteric ligand influencing GR structure and activity. Finally, we describe how the differential composition and distinct regulation at multiple levels of different GR species could account for the wide and diverse effects of glucocorticoids

    School segregation : A case study of ethnic and socioeconomic school segregation in Frödingskolan

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    Det fria skolvalet infördes Är 1992 för att möjliggöra en social förflyttning i grundskolan. Reformen syftade till att förÀldrarnas socioekonomiska samt etniska bakgrund inte skulle pÄverka elevers betyg. Ett flertal studier visar tydliga tendenser pÄ att det fria skolvalet har resulterat i det motsatta dÄ elevsammansÀttningen med tiden blivit allt mer homogen samt att betygen har försÀmrats.   Syftet med denna studie Àr att undersöka hur elevsammansÀttningen samt betyg, utifrÄn etnisk samt socioekonomisk bakgrund, pÄverkats pÄ Frödingskolan i Karlstad kommun sedan det fria skolvalet infördes. Studien utgÄr frÄn kvantitativ statistisk mellan lÀsÄren 2005/2006 samt 2016/2017. Statistiken Àr hÀmtad frÄn databasen Siris, Skolverkets internetbaserade resultat- och kvalitetinformationssystem. Insamlade data har bearbetats och redovisas genom stapeldiagram för att sedan analyseras med hjÀlp av teorier som White flight och White avoidance, Micromotives and Macrobehavior samt Bourdieus teori som behandlar utbildningskapital.   Resultatet visar att elevsammansÀttningen utifrÄn etnisk bakgrund har förÀndrats pÄ Frödingskolan genom att andelen elever med svensk bakgrund har minskat markant i jÀmförelse med elever av annan etnisk bakgrund. Resultatet visar sÄledes att det inte har skett en förÀndring i elevsammansÀttningen utifrÄn socioekonomisk bakgrund dÄ elever vars förÀldrar har en för-och gymnasial utbildning eller eftergymnasial utbildning har minskat i ungefÀr lika stor omfattning. Resultatet tyder pÄ en etnisk segregation, dÄ elevsammansÀttningen enbart förÀndrades utifrÄn etnisk bakgrund. Betygen har, till skillnad frÄn vad tidigare forskning visat, förbÀttrats i majoriteten av kategorier

    School segregation : A case study of ethnic and socioeconomic school segregation in Frödingskolan

    No full text
    Det fria skolvalet infördes Är 1992 för att möjliggöra en social förflyttning i grundskolan. Reformen syftade till att förÀldrarnas socioekonomiska samt etniska bakgrund inte skulle pÄverka elevers betyg. Ett flertal studier visar tydliga tendenser pÄ att det fria skolvalet har resulterat i det motsatta dÄ elevsammansÀttningen med tiden blivit allt mer homogen samt att betygen har försÀmrats.   Syftet med denna studie Àr att undersöka hur elevsammansÀttningen samt betyg, utifrÄn etnisk samt socioekonomisk bakgrund, pÄverkats pÄ Frödingskolan i Karlstad kommun sedan det fria skolvalet infördes. Studien utgÄr frÄn kvantitativ statistisk mellan lÀsÄren 2005/2006 samt 2016/2017. Statistiken Àr hÀmtad frÄn databasen Siris, Skolverkets internetbaserade resultat- och kvalitetinformationssystem. Insamlade data har bearbetats och redovisas genom stapeldiagram för att sedan analyseras med hjÀlp av teorier som White flight och White avoidance, Micromotives and Macrobehavior samt Bourdieus teori som behandlar utbildningskapital.   Resultatet visar att elevsammansÀttningen utifrÄn etnisk bakgrund har förÀndrats pÄ Frödingskolan genom att andelen elever med svensk bakgrund har minskat markant i jÀmförelse med elever av annan etnisk bakgrund. Resultatet visar sÄledes att det inte har skett en förÀndring i elevsammansÀttningen utifrÄn socioekonomisk bakgrund dÄ elever vars förÀldrar har en för-och gymnasial utbildning eller eftergymnasial utbildning har minskat i ungefÀr lika stor omfattning. Resultatet tyder pÄ en etnisk segregation, dÄ elevsammansÀttningen enbart förÀndrades utifrÄn etnisk bakgrund. Betygen har, till skillnad frÄn vad tidigare forskning visat, förbÀttrats i majoriteten av kategorier

    Fatigue analysis of marine boiler : Sunrod CPDB12

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    Problematik med utmattningsbrott är känt sedan början på 1800-talet och fenomenet har studerats sedan dess. Efter lång tids arbete har man hittat en metodik för att ta fram analytiska beräkningsmodeller samt säkra och noggranna livslängdsberäkningar för stålkonstruktioner. Syftet med detta arbete har varit att undersöka en marin ångpannas utmattningshållfasthet under loppet av dess ekonomiska livslängd. I den här studien har en analytisk beräkning gjorts på en marin ångpannas utmattningslivslängd med hjälp av DNV ́s regler för klassifikation av fartyg samt Europeiska tryckkärlsnormen. I studien har författarna tagit hänsyn till ångpannans tryckvariationer, temperaturvariationer samt den marina ångpannans yttre påverkan från fartygets rörelse i vattnet och de resulterande hävkrafterna. Detta för att med hög tillförlitlighet (konfidens) kunna värna om människoliv, natur och miljö, fysisk egendom (fartyg samt last), operativa tillgänglighet samt lagar och regler.Problems with fractures due to fatigue have been known since the early 19th century, and the phenomenon has been studied since then. After long periods of work, a methodology has been found to develop analytical fatigue calculation models for steel structures. The purpose of this work has been to investigate the fatigue assessments of marine boilers during it ́s economic lifetime. In this study, an analytical calculation has been made of the marine boiler using DNV's ship classification rules and the European pressure vessel standard. In the study, the authors have taken into account the boilers pressure variations, temperature variations, and the marine boiler's external impact from the vessel's motion in the water and the resulting forces. In order to be able to protect human life, nature and the environment, physical property (ships and cargo), operational availability as well as laws and regulations, with high reliability (confidentiality)
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