63 research outputs found

    AKT1/BRCA1 in the control of homologous recombination and genetic stability: the missing link between hereditary and sporadic breast cancers

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    Endogenous replicative stress could be one trigger leading to tumor initiation: indeed, activation of the DNA damage response (DDR), considered the result of replicative stress, is observed in pre-cancerous cells; moreover, in hereditary breast cancers, almost all of the genes affected relate to the DDR. The most frequently mutated gene in hereditary breast cancers, BRCA1, is essential for homologous recombination (HR), a fundamental process for maintaining genome stability that permits the reactivation of blocked replication forks. Recent studies have established links between DDR and the oncogenic kinase AKT1, which is upregulated in about 50% of sporadic breast cancers. More specifically, the activation of AKT1 shows a deficient phenotype in BRCA1 and HR, revealing molecular similarities between hereditary and sporadic breast cancers. However, these results reveal a paradox regarding the physiological role of AKT1: in non-tumor cells, AKT1 promotes cellular proliferation, but consequently endangers genome integrity during replication if HR is inhibited. Since HR could itself lead to genetic instability, we propose that, under physiological conditions, moderate activation of AKT1 does not inhibit but prevents an excess of HR. The regulation of AKT1 would represent a fine transitory system for controlling HR and maintaining genomic integrity

    Added values in groceries : a case study of a market leader

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    Konkurrensen pÄ den svenska dagligvarumarknaden Àr stor. I dagens matbutiker möts konsumenten av ett ofantligt utbud av produkter. Varje vara finns i olika mÀrken, i olika prisklasser och i olika produktutformningar med olika egenskaper. Detta gör att det Àr svÄrt för producenter att fÄ in en ny produkt pÄ marknaden och dessutom allt svÄrare att hÄlla kvar den dÀr. DÀrmed kan mervÀrdesaspekten bli allt viktigare för producenterna eftersom den ger en möjlighet till att differentiera sig frÄn konkurrenterna genom att skapa mervÀrden som konsumenten efterfrÄgar. MervÀrden ses som vÀrdeökningar för en produkt eller tjÀnst som uppkommer pÄ grund av till exempel en speciell egenskap, aktivitet, funktion eller nytta. Denna studie syftar till att förklara nÄgra av de grunder som finns för att anvÀnda mervÀrden i marknadsföringen av livsmedel. Studien förklarar ocksÄ vad Lindahls mejeriprodukter anser Àr differentieringsgrunder för deras produkt turkisk yoghurt. För att ge den empiriska studien ett djup och kontext har en kombination av flera kÀllor anvÀnts. En litteraturstudie har gjorts för att skapa en teoretisk kunskapsbas med hjÀlp av tidigare forskning och dÀrefter har en fallstudie genomförts pÄ produkten turkisk yoghurt frÄn företaget Lindahls mejeriprodukter. Den teoretiska kunskapsbasen har varit en grund för insamlingen och tolkningen av empiriskt data. NÄgra centrala begrepp inom den teoretiska kunskapsbasen Àr marknadsföringsmixen, varumÀrkesteori, köpbeslutskategorisering och mervÀrden. Det som framkommit under studien Àr att differentieringsgrunder för Lindahls mejeriprodukter Àr att de var först in pÄ marknaden, att de har ett starkt varumÀrke, en bra grundprodukt, en god kundkontakt samt Àr och har alltid varit marknadsledare i produktsegmentet matlagningsyoghurt. Vidare visar studien att de grunder för mervÀrdesskapande som anses mest betydelsefulla Àr hÀlsoaspekten, miljö- och hÄllbarhetsaspekten, identitetsskapande samt design.The competition in the Swedish grocery market is well developed. In grocery stores the consumers meet a vast range of products. Each product is available in different brands, price ranges and characteristics. This makes it difficult for producers to get their new products into the market and even more difficult to keep them there. Therefore it is possible that the aspect of added value becomes increasingly important for the producers as it provides a means to differentiate them from the competition and enables a creation of added value that the consumers demand. Added value is seen as an increase of value for a product or service that comes from special characteristics, activities, functions or benefits that is seen as additional to the expected standard. The aim of this study is to explain grounds used in marketing a food product with added values. The study also explains what the company Lindahls dairy products believe are the grounds for differentiation for their Turkish-style-yoghurt. A combination of sources has been used as a means to give the paper a greater understanding. A literature study has been done on previous research to create a theoretical knowledge-base and a case study has been done on the product Turkish-style-yoghurt from Lindahls dairy products. The theoretical knowledge-base functioned as a ground for the collecting of empirical data. Some of the key conceptions from the theoretical knowledge-base are the marketing mix, branding, buying behavior and added values. The study demonstrates that the grounds for differentiation for Lindahls dairy products are the following: they were first in the market, they have a strong brand, their product has a good standard, they have a well-established contact with their customers and they have always been the market leader in the segment of their products. Furthermore the study shows that the grounds considered the most important for creating added value are health concerns, environmental sustainability, identity creation and design

    Updating the mechanisms of common fragile site instability: how to reconcile the different views?

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    Common fragile sites (CFSs) are large chromosomal regions long identified by conventional cytogenetics as sequences prone to breakage in cells subjected to replication stress. The interest in CFSs came from their key role in the formation of DNA damage, resulting in chromosomal rearrangements. The instability of CFSs was notably correlated with the appearance of genome instability in precancerous lesions and during tumor progression. Identification of the molecular mechanisms responsible for their instability therefore represents a major challenge. A number of data show that breaks result from mitotic entry before replication completion but the mechanisms responsible for such delayed replication of CFSs and relaxed checkpoint surveillance are still debated. In addition, clues to the molecular events leading to breakage just start to emerge. We present here the results of recent reports addressing these questions

    Framskrivninger for arealbrukssektoren (LULUCF) under FNs klimakonvensjon og EUs klimarammeverk

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    Arealbrukssektoren (engelsk: Land Use, Land-Use Change and Forestry, LULUCF) omfatter arealbruk og arealbruksendringer, med tilhĂžrende utslipp og opptak av CO2, CH4 og N2O, og er en del av det nasjonale klimagassregnskapet under FNs klimakonvensjon. Framskrivningene presentert her er basert pĂ„ data og metodikk fra Norges siste rapportering til FNs klimakonvensjon (IPCC), Norges National Inventory Report (NIR), innsendt 8. april 2022 (MiljĂždirektoratet mfl. 2022). Perioden 2006 – 2020 har vĂŠrt lagt til grunn som referanseperiode, og framskrivning av arealutvikling og utslipp er i all hovedsak basert pĂ„ rapporterte data for denne tidsperioden. Utviklingen i gjenvĂŠrende skog er framskrevet ved hjelp av simuleringsverktĂžyet SiTree og Yasso07. Klimaendringer under klimascenariet i RCP 4.5 er lagt til grunn. Framskrivingen er framstilt pĂ„ to ulike formater: BĂ„de i henhold til FNs klimakonvensjon sitt regelverk (alle arealbrukskategorier og kilder) og basert pĂ„ EUs regelverk under LULUCF-forordningen (2018/841) (European Union 2018).publishedVersio

    Best Practices for Virtual Care: A Consensus Statement From the Canadian Rheumatology Association

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    Objective. To develop best practice statements for the provision of virtual care in adult and pediatric rheumatology for the Canadian Rheumatology Association\u27s (CRA) Telehealth Working Group (TWG). Methods. Four members of the TWG representing adult, pediatric, university-based, and community rheumatology practices defined the scope of the project. A rapid literature review of existing systematic reviews, policy documents, and published literature and abstracts on the topic was conducted between April and May 2021. The review informed a candidate set of 7 statements and a supporting document. The statements were submitted to a 3-round (R) modified Delphi process with 22 panelists recruited through the CRA and patient advocacy organizations. Panelists rated the importance and feasibility of the statements on a Likert scale of 1-9. Statements with final median ratings between 7-9 with no disagreement were retained in the final set. Results. Twenty-one (95%) panelists participated in R1, 15 (71%) in R2, and 18 (82%) in R3. All but 1 statement met inclusion criteria during R1. Revisions were made to 5/7 statements following R2 and an additional statement was added. All statements met inclusion criteria following R3. The statements addressed the following themes in the provision of virtual care: adherence to existing standards and regulations, appropriateness, consent, physical examination, patient-reported outcomes, use in addition to in-person visits, and complex comanagement of disease. Conclusion. The best practice statements represent a starting point for advancing virtual care in rheumatology. Future educational efforts to help implement these best practices and research to address identified knowledge gaps are planned

    Globalization and the Transmission of Social Values: The Case of Tolerance

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    Recombinaison homologue protÚge contre les défauts de la mitose et la ségrégation des chromosomes déséquilibre causé par le stress de réplication spontanée

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    Les cellules dĂ©ficientes pour la recombinaison homologue (RH) prĂ©sentent un ralentissement des fourches de rĂ©plication, un nombre aberrant de centrosomes et une aneuploĂŻdie mĂȘme en absence de stress exogĂšne (Bertrand P 2003, Daboussi F 2005, 2008, Deng 1999, 2002, Griffin 2000, Kraakman-van der Zwet 2002). De plus, la frĂ©quence des mitoses prĂ©sentant des chromosomes surnumĂ©raires est plus Ă©levĂ©e dans ces cellules.L’ensemble des ces rĂ©sultats suggĂ©raient que le ralentissement des fourches de rĂ©plication dans les cellules dĂ©ficientes pour la RH pourrait avoir un impact direct sur la formation de centrosomes surnumĂ©raires. De plus, nous voulions savoir si cela pouvait Ă©galement influencer la sĂ©grĂ©gation des chromosomes au cours de la mitose. Les rĂ©sultats que nous avons obtenus sont rassemblĂ©s dans l’article intitulé : “Homologous Recombination protects against mitotic defects and unbalanced chromosome segregation caused by spontaneous replication stress”.Le traitement des cellules compĂ©tentes pour la RH avec 5”M d’hydroxyurĂ©e (HU), un inhibiteur de l’enzyme de synthĂšse des dNTPs, induit un ralentissement des fourches de rĂ©plication parfaitement comparable Ă  celui observĂ© dans les cellules dĂ©ficientes pour la RH. AprĂšs traitement Ă  l’HU des cellules compĂ©tentes pour la RH, la frĂ©quence de mitoses prĂ©sentant des chromosomes surnumĂ©raires augmente et devient similaire Ă  la frĂ©quence de mitoses avec des chromosomes surnumĂ©raires pour les cellules dĂ©ficientes pour la HR non traitĂ©es Ă  l’HU. Nous avons mesurĂ© l’impact de l’HU sur l’apparition des ponts anaphasiques et sur des dĂ©fauts de sĂ©grĂ©gation des chromosomes lors de la mitose. En l’absence de traitement, nous observons une frĂ©quence plus Ă©levĂ©e de ponts anaphasiques et de dĂ©fauts de sĂ©grĂ©gation dans des cellules dĂ©ficientes pour la RH. Des traitements avec 5”M d’HU augmentent la frĂ©quence des ponts anaphasiques et des erreurs de sĂ©grĂ©gation dans les cellules compĂ©tentes pour la RH, pour atteindre un niveau comparable aux cellules dĂ©ficientes pour la RH. Ainsi, une altĂ©ration de la dynamique de rĂ©plication consĂ©cutive Ă  une dĂ©ficience de RH ou Ă  un traitment avec de faibles doses d’HU induit des dĂ©fauts au cours de la mitose. Un lien direct entre une dynamique de rĂ©plication anormale et l’apparition d’un nombre aberrant de centrosomes pourrait ĂȘtre la persistance en mitose d’ADN non rĂ©pliquĂ© ou endommagĂ©.  Comme l’ADN non rĂ©pliquĂ© ou les fourches bloquĂ©es induisent la formation d’ADN simple brin couvert par RPA, nous avons comptĂ© le nombre de cellules en G2/M prĂ©sentant des foyers de RPA, et observĂ© que la fraction de cellules ayant plus de 5 foyers de RPA augmente dans des cellules dĂ©ficientes pour Brca2. En conclusion, nous proposons un lien direct entre des altĂ©rations de la cinĂ©tique de rĂ©plication, l’apparition de centrosomes surnumĂ©raires et des dĂ©fauts de sĂ©grĂ©gation des chromosomes en mitose dans les cellules dĂ©ficientes pour la RH mĂȘme non soumises Ă  un stress exogĂšne. L’utilisation de faibles doses d’HU dans des cellules compĂ©tentes pour la RH mime les phĂ©notypes observĂ©s dans les cellules dĂ©ficientes pour la RH et confirme notre modĂšle.Nous avons Ă©galement cherchĂ© Ă  comprendre les causes du ralentissement des fourches de rĂ©plication observĂ© dans les cellules dĂ©ficientes pour la RH. Il est ainsi possible que les arrĂȘts de fourches spontanĂ©s soient une consĂ©quence d’un stress oxydatif endogĂšne. Dans les cellules compĂ©tentes pour la RH, le redĂ©marrage des fourches bloquĂ©es est possible et assure une progression normale de la rĂ©plication de l’ADN. Ceci favorise une sĂ©grĂ©gation Ă©quilibrĂ©e des chromosomes, le maintien de la diploĂŻdie et la stabilitĂ© du gĂ©nome. Dans des cellules dĂ©ficientes pour la RH, les blocages de fourches devraient ĂȘtre dĂ©lĂ©tĂšres puisque les principaux mĂ©canismes de redĂ©marrage des fourches ne sont pas fonctionnels. De plus, l’arrĂȘt prolongĂ© des fourches ainsi que les cassures double brin gĂ©nĂ©rĂ©es par l’effondrement des fourches devraient activer des voies de signalisation. Nous avons nĂ©anmoins observĂ© que les cellules ne sont pas bloquĂ©es dans le cycle cellulaire, ce qui suggĂšre qu’un seuil supĂ©rieur de dommages doive ĂȘtre atteint pour induire l’arrĂȘt du cycle. Les stress endogĂšnes ne semblent donc pas suffisamment Ă©levĂ©s pour atteindre ce seuil : mĂȘme si l’ensemble des fourches parcourant le gĂ©nome sont ralenties, l’activation d’origines cryptiques permet de compenser et ainsi de maintenir la progression dans le cycle. Mais puisque les cellules ne sont pas arrĂȘtĂ©es dans le cycle, des fourches bloquĂ©es, de l’ADN endommagĂ© ou non rĂ©pliquĂ© pourraient persister jusqu’à la transition G2/M et in fine perturber le dĂ©roulement de la mitose. Des centrosomes multipolaires provoquent la formation de fuseaux multipolaires et favorisent la sĂ©grĂ©gation dĂ©sĂ©quilibrĂ©e des chromosomes, entraĂźnant l’aneuploĂŻdie, la dĂ©stabilisation du gĂ©nome et le dĂ©veloppement de cancers.HR deficient cells show slow replication kinetics, aberrant centrosome number and aneuploidy even in the absence of any exogenous stress (Bertrand P 2003, Daboussi F 2005, 2008, Deng 1999, 2002, Griffin 2000, Kraakman-van der Zwet 2002). Frequency of mitosis with extra centrosomes is elevated and replication kinetics decreased in HR deficient compared to HR proficient cells, in the absence of exogenous stress. Thus the question arose, if replication slowing down in HR deficient cells has direct impact on the appearance of supernumerary centrosomes. Furthermore we wanted to know if this might directly impact chromosome segregation. The results we gained are brought together in the paper “Homologous recombination suppression causes spontaneous mitotic alterations through endogenous replication stress”. By treating our HR proficient cells with 5”M HU we found the perfect concentration to mimic replication dynamics of HR deficient cells in an HR proficient background. This concentration was applied to HR proficient cells. After HU treatment the frequency of mitosis with extra centrosomes was elevated in HR proficient cells. Now they showed the same frequency of mitosis with extra centrosomes, than unchallenged HR deficient cells. We measured the impact of HU treatment on occurrence of anaphase bridges or aberrant mitotic segregation. In the absence of treatment higher frequency of anaphase bridges and aberrant mitotic segregation was detected for HR deficient cells. With 5”M HU the frequency of anaphase bridges and aberrant mitosis could be elevated in HR proficient cells. Now they showed aberrant mitotic features with the same frequency than unchallenged HR deficient cells. A direct link between abnormal replication kinetics and aberrant centrosomes might be unreplicated or damaged DNA, that enter mitosis. Unreplicated or blocked DNA might harbour ss DNA bound RPA. Thus we counted G2/M cells with RPA foci. Indeed the fraction of cells that harbour more than 5 RPA foci was elevated in Brca2 deficient in comparison to Brca2 proficient cells. In conclusion we propose a direct link between delayed replication, supernumerary centrosomes and aberrant chromosome segregation in unchallenged HR deficient cells. If we mimicked replication kinetics of HR deficient cells in an HR proficient background, we also mimicked frequency of mitosis with extra centrosome number and aberrant chromosome segregation. Furthermore we investigated the causes of replication slowing down in HR deficient cells. It can be hypothesized that endogenous oxidative stress is implicated in spontaneous fork arrest. In HR proficient cells, reactivation of stalled replication forks and therefore normal replication progression is assured. This favours balanced chromosome segregation, diploidy and genetic stability.In HR deficient cells, replication fork blockage might be detrimental as the main restart mechanism for blocked forks is absent. Prolonged fork blockage or DSB’s arising by fork collapse or resolution of blocked replication forks might activate signalling pathways. However cells are not arrested in cell cycle progression, suggesting that a threshold should be reached to activate cell cycle arrest. Endogenous stress is not sufficient high to reach this threshold. Replication is genome wide slowed down. In this context, the activation of cryptic origins compensates at least partly the slow replication velocity. However, because cells were not arrested in cell cycle progression, some blocked replication forks and damaged or unreplicated DNA regions might persist until G2/M phase and affect centrosome duplication and chromosome segregation. Multipolar centrosomes cause multipolar spindles and favour unbalanced chromosome segregation leading to aneuploidy, genetic instability and cancer development

    Recombinaison homologue protÚge contre les défauts de la mitose et la ségrégation des chromosomes déséquilibre causé par le stress de réplication spontanée

    No full text
    Les cellules dĂ©ficientes pour la recombinaison homologue (RH) prĂ©sentent un ralentissement des fourches de rĂ©plication, un nombre aberrant de centrosomes et une aneuploĂŻdie mĂȘme en absence de stress exogĂšne (Bertrand P 2003, Daboussi F 2005, 2008, Deng 1999, 2002, Griffin 2000, Kraakman-van der Zwet 2002). De plus, la frĂ©quence des mitoses prĂ©sentant des chromosomes surnumĂ©raires est plus Ă©levĂ©e dans ces cellules.L ensemble des ces rĂ©sultats suggĂ©raient que le ralentissement des fourches de rĂ©plication dans les cellules dĂ©ficientes pour la RH pourrait avoir un impact direct sur la formation de centrosomes surnumĂ©raires. De plus, nous voulions savoir si cela pouvait Ă©galement influencer la sĂ©grĂ©gation des chromosomes au cours de la mitose. Les rĂ©sultats que nous avons obtenus sont rassemblĂ©s dans l article intitulĂ©: Homologous Recombination protects against mitotic defects and unbalanced chromosome segregation caused by spontaneous replication stress .Le traitement des cellules compĂ©tentes pour la RH avec 5 M d hydroxyurĂ©e (HU), un inhibiteur de l enzyme de synthĂšse des dNTPs, induit un ralentissement des fourches de rĂ©plication parfaitement comparable Ă  celui observĂ© dans les cellules dĂ©ficientes pour la RH. AprĂšs traitement Ă  l HU des cellules compĂ©tentes pour la RH, la frĂ©quence de mitoses prĂ©sentant des chromosomes surnumĂ©raires augmente et devient similaire Ă  la frĂ©quence de mitoses avec des chromosomes surnumĂ©raires pour les cellules dĂ©ficientes pour la HR non traitĂ©es Ă  l HU. Nous avons mesurĂ© l impact de l HU sur l apparition des ponts anaphasiques et sur des dĂ©fauts de sĂ©grĂ©gation des chromosomes lors de la mitose. En l absence de traitement, nous observons une frĂ©quence plus Ă©levĂ©e de ponts anaphasiques et de dĂ©fauts de sĂ©grĂ©gation dans des cellules dĂ©ficientes pour la RH. Des traitements avec 5 M d HU augmentent la frĂ©quence des ponts anaphasiques et des erreurs de sĂ©grĂ©gation dans les cellules compĂ©tentes pour la RH, pour atteindre un niveau comparable aux cellules dĂ©ficientes pour la RH. Ainsi, une altĂ©ration de la dynamique de rĂ©plication consĂ©cutive Ă  une dĂ©ficience de RH ou Ă  un traitment avec de faibles doses d HU induit des dĂ©fauts au cours de la mitose. Un lien direct entre une dynamique de rĂ©plication anormale et l apparition d un nombre aberrant de centrosomes pourrait ĂȘtre la persistance en mitose d ADN non rĂ©pliquĂ© ou endommagĂ©. Comme l ADN non rĂ©pliquĂ© ou les fourches bloquĂ©es induisent la formation d ADN simple brin couvert par RPA, nous avons comptĂ© le nombre de cellules en G2/M prĂ©sentant des foyers de RPA, et observĂ© que la fraction de cellules ayant plus de 5 foyers de RPA augmente dans des cellules dĂ©ficientes pour Brca2. En conclusion, nous proposons un lien direct entre des altĂ©rations de la cinĂ©tique de rĂ©plication, l apparition de centrosomes surnumĂ©raires et des dĂ©fauts de sĂ©grĂ©gation des chromosomes en mitose dans les cellules dĂ©ficientes pour la RH mĂȘme non soumises Ă  un stress exogĂšne. L utilisation de faibles doses d HU dans des cellules compĂ©tentes pour la RH mime les phĂ©notypes observĂ©s dans les cellules dĂ©ficientes pour la RH et confirme notre modĂšle.Nous avons Ă©galement cherchĂ© Ă  comprendre les causes du ralentissement des fourches de rĂ©plication observĂ© dans les cellules dĂ©ficientes pour la RH. Il est ainsi possible que les arrĂȘts de fourches spontanĂ©s soient une consĂ©quence d un stress oxydatif endogĂšne. Dans les cellules compĂ©tentes pour la RH, le redĂ©marrage des fourches bloquĂ©es est possible et assure une progression normale de la rĂ©plication de l ADN. Ceci favorise une sĂ©grĂ©gation Ă©quilibrĂ©e des chromosomes, le maintien de la diploĂŻdie et la stabilitĂ© du gĂ©nome. Dans des cellules dĂ©ficientes pour la RH, les blocages de fourches devraient ĂȘtre dĂ©lĂ©tĂšres puisque les principaux mĂ©canismes de redĂ©marrage des fourches ne sont pas fonctionnels. De plus, l arrĂȘt prolongĂ© des fourches ainsi que les cassures double brin gĂ©nĂ©rĂ©es par l effondrement des fourches devraient activer des voies de signalisation. Nous avons nĂ©anmoins observĂ© que les cellules ne sont pas bloquĂ©es dans le cycle cellulaire, ce qui suggĂšre qu un seuil supĂ©rieur de dommages doive ĂȘtre atteint pour induire l arrĂȘt du cycle. Les stress endogĂšnes ne semblent donc pas suffisamment Ă©levĂ©s pour atteindre ce seuil: mĂȘme si l ensemble des fourches parcourant le gĂ©nome sont ralenties, l activation d origines cryptiques permet de compenser et ainsi de maintenir la progression dans le cycle. Mais puisque les cellules ne sont pas arrĂȘtĂ©es dans le cycle, des fourches bloquĂ©es, de l ADN endommagĂ© ou non rĂ©pliquĂ© pourraient persister jusqu Ă  la transition G2/M et in fine perturber le dĂ©roulement de la mitose. Des centrosomes multipolaires provoquent la formation de fuseaux multipolaires et favorisent la sĂ©grĂ©gation dĂ©sĂ©quilibrĂ©e des chromosomes, entraĂźnant l aneuploĂŻdie, la dĂ©stabilisation du gĂ©nome et le dĂ©veloppement de cancers.HR deficient cells show slow replication kinetics, aberrant centrosome number and aneuploidy even in the absence of any exogenous stress (Bertrand P 2003, Daboussi F 2005, 2008, Deng 1999, 2002, Griffin 2000, Kraakman-van der Zwet 2002). Frequency of mitosis with extra centrosomes is elevated and replication kinetics decreased in HR deficient compared to HR proficient cells, in the absence of exogenous stress. Thus the question arose, if replication slowing down in HR deficient cells has direct impact on the appearance of supernumerary centrosomes. Furthermore we wanted to know if this might directly impact chromosome segregation. The results we gained are brought together in the paper Homologous recombination suppression causes spontaneous mitotic alterations through endogenous replication stress . By treating our HR proficient cells with 5 M HU we found the perfect concentration to mimic replication dynamics of HR deficient cells in an HR proficient background. This concentration was applied to HR proficient cells. After HU treatment the frequency of mitosis with extra centrosomes was elevated in HR proficient cells. Now they showed the same frequency of mitosis with extra centrosomes, than unchallenged HR deficient cells. We measured the impact of HU treatment on occurrence of anaphase bridges or aberrant mitotic segregation. In the absence of treatment higher frequency of anaphase bridges and aberrant mitotic segregation was detected for HR deficient cells. With 5 M HU the frequency of anaphase bridges and aberrant mitosis could be elevated in HR proficient cells. Now they showed aberrant mitotic features with the same frequency than unchallenged HR deficient cells. A direct link between abnormal replication kinetics and aberrant centrosomes might be unreplicated or damaged DNA, that enter mitosis. Unreplicated or blocked DNA might harbour ss DNA bound RPA. Thus we counted G2/M cells with RPA foci. Indeed the fraction of cells that harbour more than 5 RPA foci was elevated in Brca2 deficient in comparison to Brca2 proficient cells. In conclusion we propose a direct link between delayed replication, supernumerary centrosomes and aberrant chromosome segregation in unchallenged HR deficient cells. If we mimicked replication kinetics of HR deficient cells in an HR proficient background, we also mimicked frequency of mitosis with extra centrosome number and aberrant chromosome segregation. Furthermore we investigated the causes of replication slowing down in HR deficient cells. It can be hypothesized that endogenous oxidative stress is implicated in spontaneous fork arrest. In HR proficient cells, reactivation of stalled replication forks and therefore normal replication progression is assured. This favours balanced chromosome segregation, diploidy and genetic stability.In HR deficient cells, replication fork blockage might be detrimental as the main restart mechanism for blocked forks is absent. Prolonged fork blockage or DSB s arising by fork collapse or resolution of blocked replication forks might activate signalling pathways. However cells are not arrested in cell cycle progression, suggesting that a threshold should be reached to activate cell cycle arrest. Endogenous stress is not sufficient high to reach this threshold. Replication is genome wide slowed down. In this context, the activation of cryptic origins compensates at least partly the slow replication velocity. However, because cells were not arrested in cell cycle progression, some blocked replication forks and damaged or unreplicated DNA regions might persist until G2/M phase and affect centrosome duplication and chromosome segregation. Multipolar centrosomes cause multipolar spindles and favour unbalanced chromosome segregation leading to aneuploidy, genetic instability and cancer development.PARIS11-SCD-Bib. Ă©lectronique (914719901) / SudocSudocFranceF

    ”Det Ă€r bra att ha trĂ„kigt.” - en narrativanalys av genus och makt i barnlitteratur

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    Uppsatsen menar att undersöka vilka aspekter av genus och makt som kan ses i hĂ€ndelseförlopp i bilderböcker som konsumeras av barn i Ă„ldern 0–6. Bilderböcker kan ha stor inverkan pĂ„ barns syn pĂ„ genus (Peterson & Lach, 1990) och eftersom en del av en förskollĂ€rares yrkesroll Ă€r att motverka traditionella könsmönster (lpfö 16) vill vi undersöka just hur genus som presenteras för barn i hĂ€ndelseförloppen samt hur makt mellan vuxna och barn framstĂ€lls. Med stöd i Connell & Pearse (2015) genusteorier, Nikolajevas (2017) teorier om narrativ samt KĂ„relands (2013) teorier om maktkampen mellan barn och vuxna i barnlitteratur, undersöks tre böcker av den mest utlĂ„nade barnlitteraturen pĂ„ Malmö stadsbibliotek under 2018. Arbetet har utförts genom en kvalitativ narrativanalys. Analysen visar att hĂ€ndelseförloppen i böckerna bĂ„de kan ses som maskulina och feminina men en övergripande bild som utformas Ă€r vuxnas makt över barn samt en stark moralisk underton
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