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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
251

Vliv diabetogenních autoantigenů na cytokinovou odpověď mononukleárních buněk periferní krve pacientů s diabetem 1. typu / Effect of diabetogenic autoantigens on the cytokine production of peripheral blood mononuclear cells from type 1 diabetic patients

Labiková, Jana January 2012 (has links)
5 Abstract Type 1 diabetes (T1D) is a serious organ-specific autoimmune disease characterised by irreversible destruction of pancreatic β-cells by immune system. This process results in an absolute insulin deficiency. Both genetical predisposition and environmental factors influence the development of the disease. β-cell destruction is mediated by cellular components of an immune system. Proinflammatory Th1 response is considered as most pathological. Autoimmune destruction of β-cells can be identified by the detection of specific serum autoantibodies a long time before the T1D clinical onset. Currently, there is no efficient cure available to prevent or at least to delay the destructive insulitis. This diploma thesis describes the influence of synthetic diabetogenic autoantigens GAD65 and IA2 on the cytokine response of peripheral blood mononuclear cells (PBMC) obtained from T1D patients with regards to their antibody profile. The study has been carried out on patients with confirmed T1D diagnosis who tested positive for anti-GAD65 and/or anti-IA2 autoantibodies. By using flow cytometry we measured the cell type ratio in PBMC samples. The cells have been stimulated by three different concentrations of antigens and their IFNγ and IL-17 production has been detected by ELISPOT assay. In the case of both...
252

Hypoxia-Inducible Factor -1 contributes to transcriptional regulation of Bcl2-adenovirus E1B 19KDa -interacting protein in hypoxic cortical neurons

Atoui, Samira 07 April 2016 (has links)
PARP-1 has been identified as a major player in apoptotic pathways. Its excessive activation causes mitochondrial dysfunction, permeability, and AIF mitochondrion-to-nucleus translocation. It has been suggested that PARP-1 interacts indirectly with Bnip3, a mitochondrial pro-apoptotic factor. However, the mechanistic linkage is still not well understood. Our lab has shown that cytosolic/nuclear NAD+ depletion is a hallmark for PARP-1 over activation and inhibition of sirtuin activity. Specifically in my project, we think that PARP-1 induced- NAD+ depletion and sirtuin inhibition causes hyperacetylation of the α subunit of the transcription factor HIF-1 allowing increased HIF-1 binding to Bnip3 upstream promoter, and increased Bnip3 expression. Indeed, our PARP-1 Knock out neurons, MNNG and PJ34 treatment, chromatin immunoprecipitation, and HIF-1α loss of function studies strongly confirmed the necessity of HIF-1 to increase Bnip3 expression in hypoxia. Overall, our research suggests a role for HIF-1 in increasing PARP-1 dependent Bnip3 expression in hypoxic models. / May 2016
253

Barn och ungdomars erfarenheter av att leva med diabetes typ 1 : En litteraturstudie / Children and adolescents experiences of living with diabetes type 1

Harpa, Natasja, Andersson, Erika January 2017 (has links)
Bakgrund: Diabetes typ 1 är en stor folksjukdom som främst drabbar yngre människor. Att drabbas av diabetes är påfrestande fysiskt och psykiskt. Det är därför ett viktigt ämne att belysa för att kunna underlätta och förbättra vården av barn och ungdomar med diabetes. Syfte: Syftet med litteraturstudien var att belysa barn och ungdomars erfarenheter av att leva med diabetes typ 1. Metod: Litteraturstudien är en sammanställning av 10 kvalitativa studier där samtliga kvalitetsgranskats, analyserats och sammanställts. Deltagarna i litteraturstudien var 6–22 år gamla. Resultat: Resultatet visade på barn och ungdomars erfarenheter av att leva med diabetes typ 1 från att få diagnosen, ta kontroll över sjukdomen, få stöd från hälsoprofessioner, familj och vänner till att lära sig leva ett förändrat men ”normalt” liv.Konklusion: Att leva med diabetes är en ständig kamp om att leva så normalt och självständigt som möjligt. Detta underlättas genom stöd och tillräcklig information från familj och vårdpersonal. Denna fördjupande kunskap och förståelse av barn och ungdomars erfarenheter av att leva med diabetes kan bidra till förbättrad diabetesvård som kan underlätta för dessa att leva ett gott liv trots diabetes. / Background: Diabetes type 1 is a large endemic disease that mainly affects younger people. Diabetes has shown to be straining physically and psychologically and is an important subject to highlight to ease and improve the care for adolescents with diabetes. Purpose: The aim with this literature study was to highlight children and adolescents experience of living with diabetes type 1. Method: The literature study is a compilation of 10 qualitative studies that has been quality reviewed, analysed and compiled. The participants in the study was 6-22 years old. Results: The result showed children and adolescents experiences of living with diabetes type 1. From being diagnosed, taking control of the disease, getting support from healthcare, family and friends to learning how to live a changed but “normal” life.Conclusions: To live with diabetes is a constant struggle to live as normal and independent as possible. This facilitates with care and information from family and health professionals. Increased knowledge and understanding of children and adolescence experience of living with diabetes may help to improve diabetes healthcare which can ease their life despite diabetes.
254

Développement d’une nouvelle classe d'agents de sortie de latence du VIH-1 ciblant la protéine virale Tat / Development of a novel class of HIV-1 latency-reversing agent targeting the viral protein Tat

Tong, Phuoc Bao Viet 23 July 2019 (has links)
Bien que le traitement antirétroviral (ART) supprime efficacement la multiplication du VIH-1 chez les patients infectés, l’ART ne guérit pas l'infection. En effet, si l'ART est arrêté, nous observons un rebond viral. Celui–ci est principalement dû à l'activation stochastique de cellules latentes qui contiennent le génome viral intégré mais ne produisent pas de virus et ne sont donc pas ciblées par l'ART ou le système immunitaire. Ces cellules latentes sont peu nombreuses (1-10 par million de cellules T-CD4+ quiescentes) mais elles apparaissent rapidement après la primo infection et constituent donc un obstacle majeur à l'éradication virale. La stratégie la plus prometteuse pour supprimer ces cellules, dite "Shock and Kill", est de les réactiver pour qu'elles soient ensuite ciblées par l'ART et/ou lysées par les cellules T cytotoxiques. Un certain nombre d’agents de sortie de latence (LRAs) ont été mis au point pour réactiver ces cellules. Ils ciblent les protéines cellulaires telles que les Histone-désacétylases (HDAC) ou la protéine kinase C. La plupart d'entre eux présentent donc des effets non spécifiques et parfois une toxicité. Tat est la protéine du VIH-1 qui permet la transcription virale et favorise la traduction des gènes viraux. Tat est la protéine clé pour la levée de latence et l'initiation de la production des protéines virales par la cellule latente. Sur la base des structures RMN de Tat disponibles, nous avons identifié par dynamique moléculaire les conformations les plus stables de Tat. Cela nous a permis d'identifier par criblage in silico des ligands potentiels de Tat. Dix molécules ont été sélectionnées. Une molécule appelée D10 se fixe spécifiquement à la protéine Tat et augmente son activité de transactivation d'environ 4 fois. De plus, D10 présente une activité LRA sur les lignées cellulaires latentes JLat-9.2 et OM-10.1. L’activité LRA de D10 sur ces lignées représente 50 à 70% de celle du SAHA (vorinostat), un inhibiteur des HDAC candidat LRA en cours d’essais cliniques (Phase 2). Sur les cellules latentes de patients VIH traités, D10 à 50 nM a une activité LRA très efficace, 80% supérieure à celle de la bryostatine-1 qui agit sur la PKC et est considéré comme le LRA le plus prometteur actuellement. Le mécanisme d’action de D10, à semble être la stabilisation du complexe de transcription Tat-TAR. Cet effet est observé à 30 nM D10. En utilisant une approche chémoinformatique nous avons sélectionné 11 analogues de D10, dit N1-N11. Certains de ces analogues (N5, N8) montrent un effet plus fort que D10 sur l’augmentation de la transactivation de Tat ainsi que pour l’effet LRA sur les lignées cellulaires latentes. Ce résultat nous a permis d'ébaucher une relation structure chimique / activité LRA de ces molécules. Nous avons donc identifié de nouveaux agents de sortie de latence du VIH-1 ciblant Tat, plus spécifiques que les LRAs ciblant les protéines cellulaires. Ce sont les premiers activateurs de Tat identifiés. / Despite its efficiency to prevent viral multiplication, antiretroviral therapy (ART) is unable to cure patients with HIV-1. Indeed if ART is stopped, a viral rebound is observed. This increase in blood viral load is due to the activation of HIV-1 reservoirs, among which latently-infected memory CD4+ T cells. These cells are rare (1 per million of quiescent T cells) and appear very quickly following infection. To purge this long-lived reservoir the "Shock and Kill" approach was developed. This strategy relies on the use of latency reversing agents (LRAs) to induce reservoir activation. All LRAs developed until now target cellular proteins such as Histone deacetylases or protein kinase C. These LRAs are not specific for viral transcription and displayed modest effects ex vivo. Here we present a new LRA family that binds to and activates HIV-1 Tat which is the key regulator for viral transcription and latency reversal. These compounds are not cytotoxic and specifically activate Tat transcriptional activity. They were less efficient than available LRAs on HIV-1 latent cell lines. Nevertheless, when tested on latent T-cells from HIV-1 patients, the lead compound D10 was ~ 80% more efficient than bryostatin-1, one of the best LRA available to date. This effect was observed at 50 nM, which corresponds to the D10 concentration required for this compound to stabilize the Tat-TAR transcription complex. These molecules are the first Tat activators available.
255

Untersuchung der PD-1/PDL-1/PDL-2 Expression und infiltrierender T-Zellen im humanen kolorektalen Karzinom und ihre Auswirkung auf die Immunantwort / Investigation of PD-1/PDL-1/PDL-2 expression and infiltrating T cells in human colorectal carcinoma and its effect on the immune response

Königshausen, Matthias January 2007 (has links) (PDF)
Zusammenfassung Neueste Daten deuten daraufhin, dass maligne Tumoren der immunologischen Überwachung über eine Herunterregulierung der T-Zell-Aktivierung mittels eines PD-1 (programmed death 1)/ PDL-1/PDL-2 Signals ausweichen. Dies führt offensichtlich zu einer herabgesetzten Immunantwort und kann somit das Tumorwachstum fördern. Das Oberflächenmolekül PD-1, welches auf T- und B-Zellen, myeloischen Zellen und auf vielen menschlichen Karzinomen exprimiert wird, gehört zu der CD28 Familie, und PDL-1 (B7H1) und PDL-2 (B7DC) wurden als Liganden zu PD-1 beschrieben. Der CD28/B7 Signalweg gehört zu der Gruppe kostimulatorischer Signale, die beim zustande kommen einer T-Zell-gerichteten Immunantwort als zweites kostimulatorisches Signal notwendig sind. In dieser Arbeit wurde die molekulare Expression von PD-1, PDL-1 und PDL-2, von Zytokinen und T-Zell-Subpopulationen im Tumorgewebe von 81 Patienten analysiert, die sich einer kurativen oder palliativen Operation (gemäß UICC- Stadien I-IV) eines primären kolorektalen Karzinoms unterzogen hatten. Es zeigte sich auf Protein- als auch auf molekularer Ebene erstmals, dass PDL-1 und PDL-2 im Tumorgewebe fortgeschrittener Tumorstadien (UICC III/IV) signifikant überexprimiert wurden, PD-1 dagegen erniedrigt exprimiert war. PD-1 wurde dagegen deutlich auf infiltrierenden CD4+ Zellen bei Patienten fortgeschrittener Tumorstadien (UICC III/IV) detektiert, wohingegen PDL-1 auf CD4+ Zellen in frühen Stadien gefunden wurde. Im Vergleich zu den frühen Stadien (UICC I/II) wurde eine grössere Anzahl an T-Zellen mit regulatorischem Charakter in den Tumorstadien III/IV beobachtet. Letzteres würde dem Tumor im Bezug auf sein fortschreitendes Wachstum von Vorteil sein, da regulatorische T-Zellen T-Effektorzellen inhibieren können. Im Tumorgewebe fand sich zudem eine verminderte Expression an IFN-gamma, welches unter anderem T-Effektorzellen aktiviert und damit eine Immunantwort verstärkt. Das Zytokin IL-10, welches mit regulatorischen T-Zellen, aber auch mit T-Helfer (Th)2-Zellen und Tumorgewebe assoziiert ist und antiinflammatorische Eigenschaften besitzt, wurde in höheren Stadien verstärkt nachgewiesen. Dadurch verschafft es dem Tumor einen Überlebensvorteil. Die Beobachtungen in dieser Arbeit zeigen, dass PDL-1 und PDL-2 eine Schlüsselrolle während der Tumorprogression zukommen. Regulatorische T-Zellen sind offensichtlich in den Prozeß der Immunantwort gegen den Tumor eingebunden. Die deutliche PDL-1- und PDL-2-Expression auf T-Zellen insbesondere in frühen Tumorstadien lässt darauf schließen, dass die PD-1/PDL-1- bzw. PD-1/PDL-2-Interaktion inhibitorische Signale zwischen Tumorzellen und den T-Zellen vermittelt. In fortgeschrittenen Stadien (UICC III/IV) waren diese kostimulatorischen Signale auf den T-Zellen nur vermindert vorzufinden. Dies hat zur Folge, dass der Tumor sein Wachstum ungehindert fortsetzen kann, da die anti-Tumor-T-Zell-Antwort, die den Tumor normalerweise in seiner Expansion beeinträchtigt, gestört ist. Es wird somit festgestellt, dass eine Blockade der untersuchten Oberflächenmoleküle PDL-1 oder PDL-2 auf Tumorzellen eine wertvolle Option in der Immuntherapie des humanen kolorektalen Karzinoms darstellen könnte. Angesichts der diskutierten Tatsachen im Hinblick auf das Verhalten der regulatorischen T-Zellen in höheren Tumorstadien könnte sich eventuell eine Option damit eröffnen, die regulatorischen T-Zellen mittels eines spezifischen Antikörpers gegen PDL-1 und/oder PDL-2 zu beeinflussen, um somit die hemmenden Auswirkungen gegenüber der anti-Tumor-Immunantwort zu verhindern oder zu revidieren. / Summary Recent data have suggested that malignant tumors are able to escape from the immunological surveillance on a downregulation of the T cells via a PD-1 (programmed death 1) / PDL-1/PDL-2 signal. This obviously leads to a reduced immune response and thus may promote tumor growth. The surface molecule PD-1, which is expressed on T and B cells, myeloid cells and on many human carcinoma, belongs to the CD28 family, and PDL-1 (B7H1) and PDL-2 (B7DC) are ligands to PD-1. The CD28/B7 signal belongs to the group of costimulatory pathways, which is needed for a T-cell-directed immune response as a second costimulatory signal. In this work, the molecular expression of PD-1, PDL-1 and PDL-2, cytokines and T-cell-subpopulations was analyzed in tumor tissue of 81 patients, which have undergone a curative or palliative surgery (according UICC- stages I-IV) of a primary colorectal cancer. For the first time it was shown on the protein and molecular level, that PDL-1 and PDL-2 were significantly overexpressed in tumor tissue of advanced tumor stages (UICC III/IV), the expression of PD-1, on the other hand was decreased. PD-1 was much more detected on infiltrating CD4+ cells in patients of advanced tumor stages (UICC III/IV), while PDL-1 was found on CD4+ cells in the early stages. In comparison to the early stages (UICC I/II), a larger number of T cells with regulatory character in the tumor stage III/IV was observed. The latter would be an advantage for the tumor in relation to its progressive growth, because regulatory T cells are able to inhibit T-effector-cells. In tumor tissue the expression of IFN-gamma was also reduced, which among others activate T-effector-cells and thus reinforced an immune response. The cytokine IL-10, which is associated with regulatory T cells, but also with T-helper(Th)2-cells and tumor tissue, has antiinflammatory properties and was demonstrated enhanced at higher stages. Thus it gives the tumor a survival advantage. The observations in this study show that PDL-1 and PDL-2 plays a key role during tumor progression. Regulatory T cells are obviously involved in the process of immune response against the tumor. The significant PDL-1- and PDL-2-Expression on T-cells, particularly in the early stages of tumor suggests that the PD-1/PDL-1- or PD-1/PDL-2-interaction mediated inhibitory signals between tumor cells and the T-cell. In advanced stages (UICC III/IV) the costimulatory signals on T-cells were decreased. This means that the tumor's growth can continue unhindered, because the anti-tumor-T-cell-response which the tumor usually affected is disrupted in its expansion. It is thus found that a blockade of the investigated surface molecules PDL-1 and PDL-2 in tumor cells could be a valuable option in the immunotherapy of human colorectal cancer. Given the facts discussed in relation to the behavior of regulatory T cells in advanced tumor stages could possibly be an option to influence the regulatory T cells with a specific antibody against PDL-1 and / or PDL-2, thus to prevent or revise the inhibitory effects against the anti-tumor-immunresponse.
256

Framing Innovation: The Impact of the Superintendent's Technology Infrastructure Decisions on the Acceptance of Large-Scale Technology Initiatives

Arnold, Erik Paul, Cohen, Peter D., Flanagan, Gina Eva, Nolin, Anna Patricia, Turner, Henry J. January 2014 (has links)
Thesis advisor: Diana C. Pullin / Thesis advisor: Vincent Cho / A multiple-case qualitative study of five school districts that had implemented various large-scale technology initiatives was conducted to describe what superintendents do to gain acceptance of those initiatives. The large-scale technology initiatives in the five participating districts included 1:1 District-Provided Device laptop and tablet programs (DPD), a Bring Your Own Device program (BYOD), and a Blended program that included a district-sponsored Lease-To-Own laptop and tablet program (LTO). Superintendents and other personnel that were identified by each superintendent as having a key role with the technology initiative were interviewed. Key documentation regarding the large-scale technology initiative was also reviewed. To help bring perspective to the actions of superintendents surrounding large-scale technology initiatives, frame theory was used as a theoretical framework for the overall study. This study sought to determine the factors considered by superintendents in making decisions about technology infrastructure, the factors considered in making decisions about funding a large-scale technology initiative, and how technology infrastructure or funding decisions impacted the perceived acceptance of the initiative. The study found that the decisions made by superintendents with regard to the technology initiative can have an impact on the acceptance of the initiative by all stakeholders. The importance of robust and reliable Wi-Fi networks, funding for technology initiatives from multiple sources, and the significance of device capabilities and reliability were also identified as significant factors in the acceptance of large-scale technology initiatives. / Thesis (EdD) — Boston College, 2014. / Submitted to: Boston College. Lynch School of Education. / Discipline: Educational Leadership and Higher Education.
257

Managing Boundaries: The Role of Narratives at a 9-1-1 Call Center

Rothstein, Megan 11 July 2013 (has links)
Dispatchers and calltakers who work at 9-1-1 call centers are confronted with memories of emergencies they must address at work even though they are not physically present at the event. The language they use to talk about their work thus always references a potentially traumatic experience processed second-hand. These telecommunicators use personal messaging through the dispatch platform, verbal communication, and texting in cellphones to tell stories about their work and manage emergency response. Often two to three mediums are used in order to communicate different aspects of the same narrative. Through storytelling, dispatchers manage an environment influenced by social hierarchies, workplace command structures, gender dynamics, and the emotional stress of the calls they must process. The fragmented experiences of dispatchers are reflected in the disjointed methods and narrative structures of their storytelling. This study offers an approach to multi-modal communication and presents an analysis of an occupational folk group not previously studied by folklorists. / 2015-07-11
258

\"Análise do conhecimento de conteúdos fundamentais de Genética e Biologia Celular apresentado por graduandos em Ciências Biológicas\". / Analysis of the knowledge o fundamental contents of Genetics and Cellular Biology presented by graduating students in Biological Sciences.

Primon, Catia Sueli Fernandes 19 December 2005 (has links)
A Biologia hoje é a mais comentada ciência e a que ocupa maior espaço na mídia. No entanto, isso não significa que os conceitos biológicos sejam de conhecimento público, nem tampouco dos estudantes de Biologia. Para analisar o conhecimento de conceitos fundamentais de Genética, Biologia Molecular e Biologia celular apresentado por graduandos do último ano de Cursos Superiores de Ciências Biológicas é que realizamos esse trabalho de pesquisa. Iniciamos o trabalho com a seleção das questões do Exame Nacional de Cursos de Biologia (Provão) do ano de 2002 que abordavam conceitos de Genética e disciplinas correlatas, analisamos o relatório do ENC-BIO/2002 expedido pelo MEC, aplicamos questionários com as questões analisadas do ENC-BIO/2002 em 72 estudantes do último ano dos cursos de Ciências Biológicas, realizamos 33 entrevistas semi-estruturadas com estudantes do último ano dos cursos de Ciências Biológicas e, por fim, analisamos os resultados apresentados pelo relatório do MEC e das entrevistas realizadas. Concluímos que os estudantes não chegam a alcançar os objetivos que a ele são atribuídos pelo MEC, no que diz respeito à Genética e disciplinas correlatas e a maioria apresenta aprendizagem mecânica. / Biology today is the most talked about science and also the one which gets the largest media coverage. However, that doesn\'t mean that the biological concepts are of public knowledge, neither are they of knowledge of Biology students. The main objective of this research work is to analyze the knowledge of fundamental concepts of Genetics, Molecular Biology and Cellular Biology of undergraduate students, who were majoring in Biological Sciences, in their senior year. We began our work with some selected questions from the National Exam of Biology Courses (?Provão?) for 2002, we chose the ones which involved concepts of Genetics and other correlated disciplines, we analyzed the ENC-BIO/2002 report prepared by the MEC, we prepared questionnaires with the analyzed questions from the ENC-BIO/2002 and distributed them to 72 senior students who were majoring in Biological Sciences, we conducted 33 semi-structured interviews with senior students majoring in Biological Sciences and, finally, we analyzed the results presented by the MEC report and by the interviews. We concluded that the students did not achieve their goals, which were established by the MEC. These goals were related to Genetics and other correlated disciplines and most of them demonstrated only a mechanical learning.
259

Atividade anticarcinogênica da tributirina associada ou não ao sorafenibe em ratos Fischer-344 implantados com células JM-1 / Anticarcinogenic activity of tributyrinn associated or not witn sorafenib in Fischer-344 rats implanted with JM-1 cells

Fernandes, Laura Helena Gasparini 25 May 2018 (has links)
O carcinoma hepatocelular (HCC) é o sexto mais frequente e a segunda maior causa de mortalidade por câncer no mundo, além de apresentar alta taxa de recidiva. A associação de sorafenibe (SO) com agentes quimiopreventivos representa uma estratégia importante para aumentar a eficácia do tratamento e minimizar a reincidência da doença. Em estudos anteriores demonstrou-se o potencial quimiopreventivo da tributirina (TB), pró-fármaco do ácido butírico (AB), em modelo de hepatocarcinogênese experimental. A atividade da TB tem sido relacionada à inibição do desenvolvimento de lesões préneoplásicas, bem como à indução de apoptose. Assim, o presente estudo teve como objetivo avaliar a ação anticarcinogênica da TB e do SO, isoladamente ou em associação no HCC. Nesse sentido, implantes singênicos foram realizados no flanco de ratos Fischer- 344 a partir de células da linhagem neoplásica JM-1. Os animais foram distribuídos nos seguintes grupos: Grupo controle isocalórico [CO; Maltodextrina (300 mg/100 g p.c.) e solução veículo (solução de etanol a 12.5% e Cremofor a 12.5% em água estéril)]; Grupo TB (200 mg/100 g p.c. e solução veículo); Grupo SO [Maltodextrina (300 mg/100 g p.c. tosilato de SO (3 mg/100 g p.c.) em solução veículo] e Grupo associação [AS; TB (200 mg/100 g p.c) e tosilato de SO (3 mg/100 g p.c.) em solução veículo]. Os implantes de células JM-1 originaram neoplasias com características pouco diferenciadas. Os tratamentos com SO e AS retardaram (p<0,05) o desenvolvimento das neoplasias, além de reduzirem (p<0,05) suas massa e aumentem (p<0,05) a sobrevida em relação ao grupo CO. Não houve diferença na porcentagem de área necrótica das neoplasias entre os tratamentos. Porém, foi observada uma correlação negativa (p<0,05) entre o tamanho da neoplasia e a área necrótica, sendo que quanto menor a área da neoplasia maior a extensão da necrose, independente do tratamento. Foi observado aumento (p<0,05) das concentrações hepáticas de AB nos grupos TB, SO e AS. Já na neoplasia, apenas os grupos TB e SO demonstraram aumento (p<0,05) na concentração de AB. Além disso, os tratamentos com SO e AS aumentaram (p<0,05) a concentração tecidual de SO na neoplasia em relação ao CO. Nesse sentido, foi observado que grupo AS apresentou 5 vezes mais SO na neoplasia quando comparado ao grupo SO. Os tratamentos com TB e SO isoladamente ou em associação reduziram (p<0,05) a expressão de CK19 em relação ao grupo CO. Em relação à avaliação da proliferação celular, os grupos TB, SO e AS apresentaram redução (p<0,05) do índice de proliferação celular quando comparados ao grupo CO. Foi observado por meio da análise imunoistoquímica para pERK, que os animais tratados com SO e AS reduziram (p<0,05) as áreas positivas quando comparadas às dos animais do grupo CO. Além disso, também foi observada por meio de marcação imunoistoquímica uma redução (p<0,05) nas áreas positivas para CK8 nos grupos SO e AS quando comparadas às do grupo CO. Em relação à caspase-3 clivada, foi observado por imunoistoquímica que o tratamento com TB aumentou (p<0,05) o índice de células positivas para caspase-3 clivada quando comparado ao CO. Esse dado foi comprovado pela análise de western blot. Foi observado por meio da análise imunoistoquímica para H3K9, um aumento (p<0,05) da acetilação no grupo TB quando comparado ao grupo CO. Em relação à expressão em nível proteico de pAKT, foi observado por meio da análise imunoistoquímica uma redução (p<0,05) no grupo TB em comparação ao grupo CO. O presente estudo demonstrou que os implantes de células JM-1 no flanco de ratos Fischer-344 originaram neoplasias com características que lembram a organização hepatocítica de um HCC convencional. O tratamento com TB foi capaz de reduzir a proliferação celular e induzir apoptose. Os tratamentos com SO e com a AS foram capazes de retardar o desenvolvimento, aumentar a sobrevida, reduzir a massa das neoplasias, induzirem diferenciação celular e reduzirem a proliferação celular, melhorando o prognóstico da doença. Os tratamentos com SO e AS apresentaram atividade quimioterápica semelhante. No entanto, a coadministração de SO e TB foi capaz de aumentar a biodisponibilidade do SO para a neoplasia. / Hepatocellular carcinoma (HCC) is the sixth most frequent and the second largest cause of cancer mortality in the world, besides presenting a high rate of recurrence. The association of sorafenib (SO) with chemopreventive agents represents an important strategy to increase the efficacy of the treatment and to minimize recurrence of the disease. In previous studies the chemopreventive potential of tributyrin (TB), a butyric acid prodrug (AB), was demonstrated in a model of experimental hepatocarcinogenesis. TB activity has been linked to inhibition of the development of pre-neoplastic lesions as well as to the induction of apoptosis. Thus, the present study aimed to evaluate the anticarcinogenic action of TB and SO, either alone or in combination in HCC. In this sense, syngeneic implants were performed on the flank of Fischer-344 rats from cells of the JM-1 neoplastic lineage. The animals were divided into the following groups: Control group [CO; Maltodextrin (300 mg / 100g p.c.) and carrier solution (12.5% ethanol solution and 12.5% Cremophor in sterile water)]; TB group (200 mg / 100 g p.c. and carrier solution); Group SO [Maltodextrin (300 mg / 100 g pc tosylate of SO (3 mg / 100 g pc) in vehicle solution] and Association group [AS; TB (200 mg / 100 g pc) and SO tosylate (3 mg / 100 (p <0.05), the development of the neoplasms, as well as the reduction (p <0.05), and the survival rate was higher (p <0.05) than the CO group. There was no difference in the percentage of necrotic area of the neoplasms between the treatments. (p <0.05) of the hepatic AB concentrations in the TB, SO and AS groups, although the size of the neoplasia and the necrotic area were higher. In the neoplasia, only the TB and SO groups showed an increase (p <0.05) in AB concentration. In addition, treatments with SO and AS increased (p <0.05) the tissue concentration of SO in the neoplasia in relation to CO. In this sense, it was observed that AS group presented 5 times more SO in the neoplasia when compared to the SO group. Treatments with TB and SO alone or in combination reduced (p <0.05) the expression of CK19 in relation to the CO group. In relation to the evaluation of cell proliferation, the TB, SO and AS groups presented a reduction (p <0.05) in the cell proliferation index when compared to the CO group. It was observed by the immunohistochemical analysis for pERK that the animals treated with SO and AS reduced (p <0.05) the positive areas when compared to the animals of the CO group. In addition, a reduction (p <0.05) in the CK8 positive areas in the SO and AS groups when compared to the CO groups was also observed by immunohistochemical labeling. In relation to the cleaved caspase-3, it was observed by immunohistochemistry that the TB treatment increased (p <0.05) the index of caspase-3 positive cells cleaved when compared to CO. This was confirmed by western blot analysis. It was observed by immunohistochemical analysis for H3K9, an increase (p <0.05) in the acetylation of the TB group when compared to the CO group. Regarding the protein level expression of pAKT, a reduction (p <0.05) in the TB group was observed through the immunohistochemical analysis when compared to the CO group. The present study demonstrated that JM-1 cell implants in the flank of Fischer-344 mice originated neoplasms with features reminiscent of the hepatocyte organization of a conventional HCC. TB treatment was able to reduce cell proliferation and induce apoptosis. SO and AS treatments were able to delay the development, increase survival, reduce the mass of neoplasms, induce cell differentiation and reduce cell proliferation, improving the prognosis of the disease. SO and AS treatments showed similar chemotherapy activity. However, co-administration of SO and TB was able to increase the bioavailability of SO to the neolasia.
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Expressão das moléculas HLA-E em tecidos placentários de mulheres infectadas ou não pelo HIV-1 / HLA-E molecules expression in placental tissue of HIV-1 infected and non-infected women

Martinez, Juliana 28 November 2013 (has links)
Na gestação, a expressão das moléculas HLA-E ocorre principalmente nos trofoblastos extravilosos da placenta e estão associados com a inibição do sistema imune resultando na imunotolerância ao feto. Esta inibição da resposta imunológica pode ser benéfica em condições fisiológicas como a gestação, mas prejudicial na vigência de tumores e infecções. Nessa condição, tem sido descrito que o HIV infecta células trofoblásticas e utiliza a molécula HLA-E como mecanismo de escape, aumentando sua expressão para inibir a atuação de células citotóxicas. Entretanto, apesar da continua exposição viral, o fato de a maioria dos recém-nascidos não serem verticalmente infectados sugere a existência de barreiras naturalmente protetoras que previnem a transmissão materno-infantil (TMI) do HIV. Frente à escassez de estudos avaliando as moléculas HLA-E na interação imunológica materno-fetal, mais especificamente na infecção do HIV-1, e à importância que este tema tem perante a prevenção da TMI, este projeto teve o objetivo de avaliar a expressão de HLA-E em tecidos placentários de mulheres infectadas ou não pelo HIV-1. Trata-se de um estudo transversal, ao qual foram submetidos ao processamento imunohistoquímico tecido placentário parafinado de 106 mulheres infectadas pelo HIV-1 e de 100 mulheres não infectadas. A expressão da molécula HLA-E foi analisada por um patologista e classificada qualitativamente como leve, moderada ou intensa e quantitativamente como negativa (<5% de marcação), 1+ (6-25%), 2+ (26-50%), 3+ (51-75%) e 4+ (>75%). Os resultados sociodemográficos apontam que as gestantes infectadas pelo HIV-1 eram mulheres não vivendo em união conjugal (p<0,0001) e com baixa escolaridade (p=0,0004). Na análise imunohistoquímica, ficou evidente que a expressão do HLA-E ocorreu principalmente na região do trofoblasto extraviloso e em células endoteliais, mas não nas vilosidades da placenta. Os testes de estatísticos utilizados foram Qui-quadrado e exato de Fisher. Os resultados mostraram que em mulheres portadoras da infecção pelo HIV-1, a expressão das moléculas HLA-E estava significantemente menor entre as que apresentavam carga viral indetectável (p=0,03), e não houve associação entre a expressão das moléculas HLA-E com outras condições como presença ou não da infecção pelo HIV, ocorrência de aborto em gestações anteriores, número de células CD4+ e terapia antirretroviral utilizada. Estes resultados sugerem que o HIV-1 induz a expressão de HLA-E em células placentárias, podendo ser utilizado como mecanismo de escape do sistema imunológico. Entretanto outros trabalhos com polimorfismos genéticos e microRNAs são necessários para ampliar o conhecimento sobre a molécula, sua atuação na infecção pelo HIV- 1 e seu papel na TMI / During pregnancy, the expression of HLA -E molecules occurs mainly in extravillous trophoblasts of the placenta and are associated with the inhibition of the immune system resulting in immune tolerance to the fetus. This inhibition of the immune response may be beneficial in physiological conditions such as pregnancy, but harmful in the presence of tumors and infections. In this condition, it has been reported that HIV infects trophoblast cells and uses the HLA -E as an escape mechanism, increasing its expression to inhibit the activity of cytotoxic cells. However, despite the continued viral exposure, the fact that most newborns are not vertically infected suggests the existence of naturally protective barriers that prevent mother to child transmission (MTCT) of HIV. Due to the lack of studies evaluating HLA-E in the maternal-fetal immunological interaction, specifically in HIV-1 infection, and the importance that this topic has towards the prevention of MTCT, this project aimed to evaluate the expression of HLA-E in placental tissues of infected women or not by HIV-1. It is a cross sectional study, which were submitted to immunohistochemical processing the paraffin- embedded placental tissue of 106 women infected with HIV-1 and 100 uninfected women. The expression of HLA-E was analyzed by a pathologist and classified qualitatively as mild, moderate or severe and quantitatively as negative (<5% markup), 1+ (6-25 %), 2+ (26-50%), 3+ (51-75%) and 4+ (>75%). The sociodemographic results indicate that pregnant women infected with HIV-1 were not women living in marital union (p<0,0001) and have lower education (p=0,0004). In immunohistochemical analysis, it became evident that the expression of HLA-E occurred mainly in the extravillous trophoblast and endothelial cells, but not in the villi of the placenta. The statistical tests used were chi-square and Fisher exact tests. The results showed that in women with the HIV-1 infection, the expression of HLA-E was significantly lower among those who had undetectable viral load (p=0,03), and there was no association between the expression of HLA- E with other conditions such as the presence or absence of HIV infection, miscarriage in previous pregnancies, number of CD4+ cells and antiretroviral therapy used. These results suggest that HIV-1 induces the expression of HLA-E placental cells, using it as a mechanism to escape the immune system. However other studies with genetic polymorphisms and microRNAs are needed to increase knowledge about the molecule, its role in HIV-1 infeccion and its role in MTCT

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