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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.
331

Veränderungen von B-Zellantigenen unter Rituximab-Therapie / FMC7 ist Teil des CD20-Antigenkomplexes

Jordanova, Maya 28 June 2004 (has links)
Das FMC7-Antigen, eine unbekannte B-Zell-Membranstruktur, dient als eines der immunphänotypischen Grundkriterien zur Diagnose der typischen B-CLL. Die unterschiedliche CD20-Expressionsintensität ist auch ein charakteristisches Merkmal bei der Subtypisierung der Lymphomentitäten. In der vorliegenden Arbeit wurde die Modulation des CD20- und des FMC7-Antigens während einer Therapie mit CD20-Antikörper (Rituximab) bei Patienten mit indolenten B-Zell-Lymphomen untersucht. Bei der durchflusszytometrischen Untersuchung quantitativer und qualitativer Charakteristika der monoklonalen B-Zell-Population bei CLL- (n=12) und Non-CLL-Patienten (n=10) unmittelbar nach der Antikörperinfusion und bis zur 8. Woche nach der Therapie wurden parallele Veränderungen von FMC7 und CD20 festgestellt. Die Anzahl und die Fluoreszenzintensitäten der für die beiden Antigene positiven Zellen korrelierten signifikant sowohl bei der malignen Zell-Population (Kurzzeitbeobachtung: n=89; r=0,9; p / The FMC7, although being an unknown structure of the B-cell membrane, represents one of the basic immunophenotypic criteria for the diagnosis of the typical B-CLL. A different CD20 expression is a characteristic sign for the sub-typing of lymphomas also. The underlying study investigated the qualitative and quantitative modulation of the CD20 and FMC7 antigens in patients with indolent B-cell lymphomas (CLL, n=12 and non-CLL, n=10) during the therapy with a CD20 antibody (rituximab). Concomitant changes of FMC7 and CD20 expression were found immediately after rituximab infusion and up to 8 weeks thereafter. A correlation was seen for the number of positive malignant cells and for the corresponding fluorescence intensity (short-time observation n=89; r=0.9; p
332

Untersuchung entfernt lokalisierter Gewebeproben kutaner B-Zell-Lymphome auf intraklonale Diversität mit der Einzel-Zell-PCR-Technik

Jacobs, Claudia 17 July 2000 (has links)
Zusammenfassung Die molekularbiologischen Untersuchungen der variablen Genabschnitte der Immunglobulingene von Lymphomzellen zweier Patienten mit kutanen B-Zell-Lymphomen wurden in der vorliegenden Arbeit mittels Einzel-Zell-PCR-Technik durchgeführt. Die erfolgte Analyse galt bevorzugt dem Aspekt der intraklonalen Diversität. Die Sequenzanalysen der Ig-Gene für die leichte Kette aus den insgesamt 100 untersuchten Tumorzellen des Patienten WS ergaben, daß zwischen den Zellen aus drei voneinander entfernt lokalisierten Gewebeproben intraklonale Diversität vorlag. Aufgrund der Mutationsanalysen und der Zuordnung der Subklone zu den Entnahmeorten ist eine evtl. antigengetriebene Entwicklung des Tumorklons zu vermuten. Bei Patient LB konnte trotz des großen Aufwandes, der Untersuchung von insgesamt 126 Zellen aus acht räumlich getrennten Biopsien, keine intraklonale Diversität für die schwere Kette der Immunglobulingene aufgezeigt werden. Die Sequenzunterschiede der leichten Kette beruhen auf einer einzigen stummen Mutation im Bereich der CDR 1, die keinen funktionellen Einfluß auf die Aminosäuresequenz hat und deshalb geringe prognostische Bedeutung besitzt. In beiden Fällen lagen hypermutierte Immunglobulingene vor. Die Tumorzellen des Patienten WS sind aus molekularbiologischer Sicht Keimzentrumszellen, die des Patienten LB eher Nachkeimzentrumszellen zuzuordnen. Die gewonnenen Erkenntnisse zeigen, daß bei der Untersuchung und Erforschung der Pathogenese von kutanen B-Zell-Lymphomen eine gewonnene Gewebeprobe nicht repräsentativ für den gesamten Tumor sein muß. Veröffentliche Ergebnisse, bei denen Monoklonalität anhand einer Biopsie postuliert wurde, müssen daher initial überdacht werden (74;76;77;84). Es ist folglich in Betracht zu ziehen, daß bei einer exakten molekularbiologischen Zuordnung der Tumorzellen zu ihrem Entwicklungsstadium und ihrer Herkunft räumliche als auch zeitliche Faktoren zu beachten sind. Eine chronologische Untersuchung könnte aufzeigen, ob andauernde Mutationen in den Tumorzellen stattfinden. Die Mikromanipulation und die Einzel-Zell-PCR-Technik sind elegante Methoden, um intraklonale Sequenzunterschiede aufzuzeigen und einen Beitrag für die molekularbiologische Erforschung der Pathogenese von kutanen B-Zell-Lymphomen zu leisten. Eine Kontrolle von malignoproliferativen Krankheiten, ob es unter den heutigen Therapiemöglichkeiten gelingt, den malignen Tumorklon vollständig zu beseitigen oder Aussagen über Progredienz und Prognose zu treffen, wäre ein interessanter Einsatzbereich dieser Methode. / abstract The molecularbiological investigation of the immunoglobulin variable region genes of two patients suffering on primary cutaneous B-cell-lymphoma was carried out using single-cell- PCR technic. The main focus lay on the aspect on the aspect of detecting intraclonal diversity. The sequence nucleotid-analysises of the immunoglubulin light chain genes obtained from a total of 100 investigated tumor B-cells in patient WS revealed intraclonal diversity among cells isolated from three spatially separated tissue samples. Considering the mutational pattern and the subclones in dependence on the tumorcells, taken from different topographical tumorsides, an antigen-driven clonal expansion could be supposed. Despite extensive efforts and the analysis of altogether 126 tumor B-cells out of eight spatially different localised biopsies, no intraclonal diversity could be observed for the immunoglobulin heavy chain rearrangement of second patient LB. Sequence differences of the Ig light chain based on only a single silent mutation within the CDR1 region. This mutation has no functional affect of the amino acid sequence and therefore little prognostical significance. In both cases the immunoglobulin genes were somatically hypermutated in compromise to the germ-line gene. From the molecularbiological point of view, the tumor cells of patient WS descended from germinal center cells, whereas the tumor B-cells of patient LB rather can be characterized as post-germinal center cells. The results clearly demonstrate, that the investigation of a single tissue sample of primary cutaneous B-cell lymphoma using micromanipulation and single cell-PCR technic may not be representative for the whole tumor. Publications concluding monoclonality with no intraclonal diversity from the analysis of a single biopsie therefore have to be interpreted with caution (74;76;77;84). Accordingly, an appropiate molecularbiological characterization of tumor B-cells regarding their developmental stage and origin has to consider spatial and time dependant aspects. Only the investigation of sequential biopsies may reliably detect ongoing mutations in tumor B-cells. The combination of micromanipulation and single cell PCR represents an elegant method to observe intraclonal diversity. The technic will give contribution to molecularbiological investigation of the pathogenesis of primary cutaneous B-cell lymphomas. It could be of interest to apply this method to the evaluation of current therapies with respect to its capability to eradicating the malignant cell clone completely, and to draw conclusions on disease progression and prognosis.
333

Le rôle du CD40 homodimère dans la réponse immunitaire

Jundi, Malek 06 1900 (has links)
Le CD40 est une glycoprotéine transmembranaire de type I, appartenant à la famille des TNFRs, exprimée à la surface des cellules immunitaires, hématopoïétiques, vasculaires, épithéliales, et d’autres types de cellules, y compris les cellules tumorales. Le CD40 ne possédant pas de domaine kinase, pour induire un signal il interagit directement ou indirectement avec des protéines adaptatrices telles que les TRAFs et les JAKs. L’interaction du CD40 avec son principal ligand, le CD154, joue un rôle primordial dans la régulation de la réponse immunitaire et le maintien de l’homéostasie. L’activation du CD40 à la surface des cellules B augmente leur capacité de présentation d’antigène, en plus d’induire la prolifération, la commutation isotypique et l’apoptose. Les patients souffrant de mutations au niveau du gène codant pour le CD40 ou de son ligand sont immunosupprimés et sensibles à des infections opportunistes. Des études ont montré que le CD40 comme d’autres membres de la famille des TNFRs est capable de former des homodimères. Plus récemment, on a montré que la formation du CD40 homodimère est le résultat de son engagement sur les cellules B. En plus, cette homodimérisation du CD40 est importante pour la phosphorylation de l’Akt. L’interaction CD40/CD154 peut avoir un rôle direct dans l’immunothérapie par l’induction de l’apoptose de certaines cellules cancéreuses ou un rôle indirect en activant les cellules présentatrices d’antigènes (CPA) afin d'augmenter l’efficacité de l’activation des cellules T cytotoxiques. Nos résultats montrent que l’induction de la mort cellulaire par le CD40 requiert la perméabilisation du lysosome, la libération de la cathepsine B, la présence de ROS et une interaction avec le TRAF6, cette mort cellulaire programmée est plus importante en présence de la forme monomérique du CD40, muté au niveau de la cystéine 238. Par ailleurs, l’homodimérisation du CD40 requerrait sa translocation vers les radeaux lipidiques et nécessiterait la présence des ROS. Cette homodimérisation du CD40 semble être importante pour l’activation des cellules B par le biais de l’induction de l’expression du CD23, CD69 et CD80. De plus, nos résultats montrent pour la première fois une implication du CD40 homodimère dans l’induction du CD23 par le biais du TLR4. Nos résultats soulignent l’importance du CD40 homodimère dans certaines voies de signalisation. Ainsi, ils mettent en évidence le rôle de la Cys-238 dans la coopération entre des récepteurs de la réponse immunitaire innée et adaptative. Toutes ces données permettraient une meilleure compréhension de certaines voies de signalisation impliquées dans plusieurs maladies auto-immunes et faisant objet de plusieurs essais thérapeutiques. / CD40 is a type I transmembrane glycoprotein belonging to the TNFRs family, which is expressed on the surface of immune, hematopoietic cells, vascular, epithelial, and other cell types, including a wide range of tumour cells. CD40 does not have a kinase domain. Thus, to induce a signal, CD40 interacts directly or indirectly with adapter proteins such as TRAFs and Jaks. The interaction of CD40 with its main ligand, CD154, plays an important role in regulating the immune response and homeostasis. The activation of CD40 on the surface of B cells increases its ability to promote antigen presentation, in addition to inducing proliferation, isotype switching, and apoptosis. Patients affected by mutations in the gene encoding the CD40 or its ligand are immunosuppressed and susceptible to opportunistic infections. Studies have shown that CD40, as other members of the family of TNFRs is capable of forming homodimers. More recently, it was shown that the formation of the CD40 homodimer is the result of the engagement of CD40 on B cells by CD154. In addition, the homodimerization of CD40 is important for the phosphorylation of Akt. The CD40/CD154 interaction can have a direct role in immunotherapy by inducing apoptosis of some cancer cells or an indirect role in activating antigen-presenting cells (APCs), thereby increasing the effectiveness of activation of cytotoxic T cells. Our results show that the induction of cell death by CD40 requires permeabilization of the lysosome, the release of cathepsin B, the presence of ROS and interaction with TRAF6, this programmed cell death is greater in the presence of the monomeric form of CD40, due to a mutation at the level of the cysteine 238. Moreover, the homodimerization of CD40 requires its translocation to lipid rafts and the presence of ROS. This homodimerization is necessary for the CD40 B-cell activation via the induction of expression of CD23, CD69 and CD80. In addition, our results show for the first time the involvement of the CD40 homodimer in the induction of CD23 expression via TLR4. Our results emphasize the importance of CD40 homodimer in signaling pathways and highlight the role of Cys-238 in the cooperation between receptors of the innate and adaptive immune response. All together our results will allow a better understanding of CD40 signaling pathways involved in several autoimmune diseases, which give a rise to a better therapeutic trial design.
334

Einfluss des Transkriptionsfaktors B-cell lymphoma 6 (BCL6) auf die Expression renaler Transportproteine / The effect of the transcription factor B-cell lymphoma 6 (BCL6) on the expression of renal transport proteins

Millé, Aline Noel 07 November 2016 (has links)
No description available.
335

Prognostički značaj određivanja koncentracija citokina članova superfamilije tumor nekrozis faktora alfa kod obolelih od sepse / Concentrations of the tumor necrosis factor alfa superfamily members as a prognostic factors in sepsis

Lendak Dajana 30 September 2015 (has links)
<p>Uvod: Nespecifičnost kliničke slike sepse, velike individualne razlike u odgovoru organizma na infekciju kao i neophodnost adekvatne inicijalne procene težine kliničke slike, toka i ishoda bolesti, čine istraživanja biomarkera koji bi doprineli pravovremenom postavljanju dijagnoze i adekvatnoj prognozi bolesti izuzetno značajnim. Do sada je ispitivano preko 200 biomarkera od kojih ni jedan nije pokazao zadovoljavajuću senzitivnost i specifičnost. Uloga B limfocita u patogenezi sepse pri tome je nedovoljno istražena. Članovi superfamilije tumor-nekrozis faktora alfa: A proliferation inducing ligand (APRIL), Bcell activating factor (BAFF) i solubilni transmembrane activator and calcium modulator cyclophilin ligand interactor (sTACI) su citokini koji imaju ključnu ulogu u homeostazi B limfocita. Cilj istraživanja bio je da se ispita dijagnostički i prognostički značaj citokina članova superfamilije tumor nekrozis faktora alfa (APRIL, BAFF, sTACI) za procenu težine kliničke slike, razvoja multiorganske disfunkcije (MODS) u prvih 48h hospitalizacije i letalnog ishoda sepse. Ispitanici i metode: Istraživanjem je obuhvaćeno 150 obolelih od sepse lečenih na Klinici za infektivne bolesti i Odeljenju anestezije i reanimacije Kliničkog centra Vojvodine i 30 zdravih dobrovljnih davalaca krvi. Kod svih bolesnika evidentirani su demografski i ostali podaci iz istorije bolesti kao i laboratorijske analize u okviru rutinske dijagnostike sepse. Iz dodatnih 5ml venske krvi svim ispitanicima određene su koncentracije APRIL-a, BAFF-a, sTACI-ja ELISA metodom komercijalnim testovima proizvođača R&amp;D Systems. Rezultati pokazuju da su koncentracije sva tri citokina (APRIL, BAFF i sTACI) statistički značajno povi&scaron;ene kod obolelih od sepse u odnosu na zdravu populaciju (p&lt;0.001), pri čemu APRIL pokazuje najveću senzitinvost (99%) i specifičnost (97%). Najveći dijagnostički značaj BAFF-a ogleda se u sposobnosti distinkcije između sepsi uzrokovanih Gram pozitivnim i Gram negativnim bakterijama (p=0,03). U predikciji razvoja MODS-a i letalnog ishoda sepse multivarijantnom regresionom analizom kao nezavisni prediktori pokazali su se jedino antiinflamatorni biomarker sTACI receptor i klinička procena pacijenta iskazana kroz APACHE II i SOFA skor. Senzitivnost i specifilnost sTACI receptora u predikciji razvoja MODS-a i letalnog ishoda daleko nadma&scaron;uje do sada rutinski kori&scaron;ćen prokalcitonin. Zaključak: Dobijeni rezultati ukazuju na to da su citokini koji učestvuju u regulaciji funkcije B limfocita značajni dijagnostički i prognostički parametri u sepsi. Predominacija antiinflamatornog odgovora na koju ukazuju povi&scaron;ene koncentracije sTACI receptora pokazala se pored APACHE II i SOFA skora kao jedini nezavisni prediktor razvoja MODS-a i letalnog ishoda septičnih bolesnika. Neophodna su dalja istraživanja u pravcu određivanja momenta kada u imunskom odgovoru organizam prelazi iz stanja dominacije proniflamatornog u dominaciju antiinflamatornog odgovora radi pravovremenog reagovanja imunomodulatornom terapijom.</p> / <p>Introduction: The nonspecific clinical presentation of sepsis and great individual response variations, as well as huge significance of adequate early prognosis of its clinical course and outcome made sepsis biomarkers research extremely significant. The properties of more than 200 biomarkers have been evaluated for prognostic value, but none have adequate specificity and sensitivity. The role of the B cells in sepsis pathogenesis also remains unclear. Tumor necrosis factor alpha (TNF-&alpha;) superfamily members: A proliferation inducing ligand (APRIL), Bcell activating factor (BAFF) and soluble transmembrane activator and calcium modulator cyclophilin ligand interactor (sTACI) are key factors in B cell biology. The aim of the study was to evaluate the diagnostic and prognostic significance of determining the concentrations of tumor necrosis factor alpha superfamily members for the prediction of MODS development in the first 48h of hospitalization as well as outcome prediction.<br />Subjects and methods: The study included 150 patients suffering from sepsis treated at the Clinic for infectious diseases and Department for anesthesiology and reanimatology of the Clinical center of Vojvodina, and 30 healthy volunteer blood donors. The demographic and other data regarding routine blood analysis performed during sepsis treatment of the patients has been acquired from their hospitalization documentation. Additional 5 ml of venous blood was taken from the patients and the concentrations of APRIL, BAFF and sTACI have been determined using the ELISA method by using R&amp;D Systems commercial kit&rsquo;s. Results: There is a statistically significant difference in concentrations of APRIL, BAFF and sTACI between healthy blood donors and septic patients (p&lt;0.001). APRIL showed the highest sensitivity (99%) and specificity (97%) in distinguishing sepsis from healthy subjects. BAFF showed statistically significant higher concentrations in Gram positive than in Gram negative sepsis (p=0,03). In the multivariate logistic regression analysis, only anti-inflammatory cytokine sTACI and APACHE II or SOFA score remained significant predictors of MODS and lethal outcome. sTACI showed greater sensitivity and specificity for MODS and outcome prediction then the widely used procalcitonin.&nbsp; Conclusions: The concentrations of TNF superfamily members, the main regulators of B cell function, have a significant diagnostic and prognostic value in predicting sepsis course and outcome. The predomination of the anti-inflammatory response, as being pointed out by elevated concentrations of sTACI receptors, has proved to be the only independent predictor, besides APACHE II and SOFA score, in MODS and lethal outcome development in sepsis. Further research is needed in order to accurately determine the exact moment when the immunological response shifts from the predominance of the pro-inflammatory response to the predominance of the anti-inflammatory response, so as to ensure the timely application of therapy that modulates the immunological response.</p>
336

Le rôle du CD40 homodimère dans la réponse immunitaire

Jundi, Malek 06 1900 (has links)
Le CD40 est une glycoprotéine transmembranaire de type I, appartenant à la famille des TNFRs, exprimée à la surface des cellules immunitaires, hématopoïétiques, vasculaires, épithéliales, et d’autres types de cellules, y compris les cellules tumorales. Le CD40 ne possédant pas de domaine kinase, pour induire un signal il interagit directement ou indirectement avec des protéines adaptatrices telles que les TRAFs et les JAKs. L’interaction du CD40 avec son principal ligand, le CD154, joue un rôle primordial dans la régulation de la réponse immunitaire et le maintien de l’homéostasie. L’activation du CD40 à la surface des cellules B augmente leur capacité de présentation d’antigène, en plus d’induire la prolifération, la commutation isotypique et l’apoptose. Les patients souffrant de mutations au niveau du gène codant pour le CD40 ou de son ligand sont immunosupprimés et sensibles à des infections opportunistes. Des études ont montré que le CD40 comme d’autres membres de la famille des TNFRs est capable de former des homodimères. Plus récemment, on a montré que la formation du CD40 homodimère est le résultat de son engagement sur les cellules B. En plus, cette homodimérisation du CD40 est importante pour la phosphorylation de l’Akt. L’interaction CD40/CD154 peut avoir un rôle direct dans l’immunothérapie par l’induction de l’apoptose de certaines cellules cancéreuses ou un rôle indirect en activant les cellules présentatrices d’antigènes (CPA) afin d'augmenter l’efficacité de l’activation des cellules T cytotoxiques. Nos résultats montrent que l’induction de la mort cellulaire par le CD40 requiert la perméabilisation du lysosome, la libération de la cathepsine B, la présence de ROS et une interaction avec le TRAF6, cette mort cellulaire programmée est plus importante en présence de la forme monomérique du CD40, muté au niveau de la cystéine 238. Par ailleurs, l’homodimérisation du CD40 requerrait sa translocation vers les radeaux lipidiques et nécessiterait la présence des ROS. Cette homodimérisation du CD40 semble être importante pour l’activation des cellules B par le biais de l’induction de l’expression du CD23, CD69 et CD80. De plus, nos résultats montrent pour la première fois une implication du CD40 homodimère dans l’induction du CD23 par le biais du TLR4. Nos résultats soulignent l’importance du CD40 homodimère dans certaines voies de signalisation. Ainsi, ils mettent en évidence le rôle de la Cys-238 dans la coopération entre des récepteurs de la réponse immunitaire innée et adaptative. Toutes ces données permettraient une meilleure compréhension de certaines voies de signalisation impliquées dans plusieurs maladies auto-immunes et faisant objet de plusieurs essais thérapeutiques. / CD40 is a type I transmembrane glycoprotein belonging to the TNFRs family, which is expressed on the surface of immune, hematopoietic cells, vascular, epithelial, and other cell types, including a wide range of tumour cells. CD40 does not have a kinase domain. Thus, to induce a signal, CD40 interacts directly or indirectly with adapter proteins such as TRAFs and Jaks. The interaction of CD40 with its main ligand, CD154, plays an important role in regulating the immune response and homeostasis. The activation of CD40 on the surface of B cells increases its ability to promote antigen presentation, in addition to inducing proliferation, isotype switching, and apoptosis. Patients affected by mutations in the gene encoding the CD40 or its ligand are immunosuppressed and susceptible to opportunistic infections. Studies have shown that CD40, as other members of the family of TNFRs is capable of forming homodimers. More recently, it was shown that the formation of the CD40 homodimer is the result of the engagement of CD40 on B cells by CD154. In addition, the homodimerization of CD40 is important for the phosphorylation of Akt. The CD40/CD154 interaction can have a direct role in immunotherapy by inducing apoptosis of some cancer cells or an indirect role in activating antigen-presenting cells (APCs), thereby increasing the effectiveness of activation of cytotoxic T cells. Our results show that the induction of cell death by CD40 requires permeabilization of the lysosome, the release of cathepsin B, the presence of ROS and interaction with TRAF6, this programmed cell death is greater in the presence of the monomeric form of CD40, due to a mutation at the level of the cysteine 238. Moreover, the homodimerization of CD40 requires its translocation to lipid rafts and the presence of ROS. This homodimerization is necessary for the CD40 B-cell activation via the induction of expression of CD23, CD69 and CD80. In addition, our results show for the first time the involvement of the CD40 homodimer in the induction of CD23 expression via TLR4. Our results emphasize the importance of CD40 homodimer in signaling pathways and highlight the role of Cys-238 in the cooperation between receptors of the innate and adaptive immune response. All together our results will allow a better understanding of CD40 signaling pathways involved in several autoimmune diseases, which give a rise to a better therapeutic trial design.
337

Vývoj B buněk u prasat a úloha gama delta T lymfocytů při imunizaci naivního imunitního systému. / The development of swine B cells and the role of gama delta T lymphocytes in immunization of naive immune system.

Štěpánová, Kateřina January 2013 (has links)
Thesis summary The process of B cell lymphogenesis in swine remains uncertain. Some reports indicate that pigs belong to a group of animal that use ileal Peyers's patches (IPP) for the generation of B cells while others point to the possibility that the bone marrow is functional throughout life. The functional subpopulations of B cells in swine are also unknown. Together with other ruminants, and also birds, γδ T cells in swine may account for >70% of all T cells which is in apparent contrast with humans and mice. The purpose of this thesis was to address these discrepancies and unresolved issues. The results disprove the existing paradigm that the IPP is primary lymphoid tissue and that B cells develop in IPP in an antigen-independent manner. On the other hand, it shows that bone marrow is fully capable of B cell lymphogenesis and remains active at least for the same period of time as it had been speculated for the IPP. This thesis also identified functionally different subsets of porcine peripheral B cells, and shows that CD21 molecules can be expressed in differential forms. Finally, this thesis identifies two lineages of γδ T cells that differ in many functional and phenotype features. This finding may explain why γδ T cells constitute of minority of lymphocytes in circulation of humans and mice.
338

Detecção da expressão dos genes associados à resistência múltipla à droga, OCT1 e MDR1 e do gene BCL2 em linfoma difuso de grandes células B\" / Detection of the expression of genes associated with multiple drug resistance, OCT-1 and MDR-1 and BCL-2 gene in diffuse large B-cell lymphoma

Gouveia, Gisele Rodrigues 15 February 2017 (has links)
O linfoma difuso de grandes células B (LDGCB) é o subtipo de linfoma mais comum em países em desenvolvimento. Entretanto, apesar de sua prevalência e importância, ainda existem poucas publicações com dados epidemiológicos para a população brasileira. Conhecer os fatores de prognóstico é imperativo para identificar os pacientes que responderão melhor ao tratamento, além de permitir sua individualização terapêutica. Alguns estudos demonstraram que pacientes com o mesmo Índice Internacional de Prognóstico (IPI) podem apresentar diferentes sobrevidas, justificando a necessidade de identificar novos marcadores biológicos de prognóstico. O objetivo deste estudo foi avaliar o impacto prognóstico da expressão dos genes BCL2, MDR1 e OCT1, de suas respectivas proteínas e da translocação t(14;18), nos desfechos de resposta completa (RC), sobrevida global (SG), sobrevida livre de doença (SLD) e sobrevida livre de progressão (SLP) em pacientes com LDGCB. Foram avaliados de forma retrospectiva 98 pacientes com LDGCB de novo tratados com R-CHOP. A expressão gênica foi avaliada por PCR em Tempo Real com RNA extraído de amostras parafinadas. A expressão proteica foi avaliada pelo método de imuno-histoquímica. A mediana de idade foi de 54,5 anos e 49 pacientes (50%) eram do sexo masculino. Sessenta e quatro pacientes (85,3%) obtiveram RC, com uma mediana de acompanhamento de 2,66 anos. A expressão mediana de BCL2, MDR1 e OCT1 foi 6,27; 0 e 24,49, respectivamente. Não encontramos impacto prognóstico da expressão do gene BCL2 na RC (p=0,277), SG (p=0,068) e SLD (p=0,860). Porém, a expressão de BCL2 >= à mediana associou-se à menor SLP (p=0,040). Encontramos associação entre expressão do gene OCT1 >= à mediana e pior prognóstico para SG (p=0,010) e SLP (p=0,016). Porém, não observamos impacto prognóstico da expressão de OCT1 para RC (p=0,464) e SLD (p=0,717). Não houve associação entre expressão do gene MDR1 e das proteínas BCL-2, Pg-p e OCT-1 com o prognóstico dos pacientes em relação à RC, SG, SLD e SLP. O número de sítios extralinfonodais (p=0,004 e p=0,005), estádio clínico (p < 0,001 para ambas), IPI (p < 0,001 para ambas) e nível de DHL (p=0,010 e p=0,008) apresentaram impacto prognóstico na SG e SLP, respectivamente. Quando os pacientes foram estratificados pelo estádio, IPI e idade, o grupo com expressão de OCT1 >= à mediana e IPI intermediário-alto ou alto risco apresentou pior SG (p=0,048) e o grupo com idade >= 60 anos e expressão de OCT1 >= à mediana apresentou pior prognóstico para SG e SLP (p=0,025 para ambas). Em conclusão, a expressão de MDR1 não apresentou impacto no prognóstico de portadores de LDGCB, porém, a expressão do gene BCL2 >= à mediana foi associada a menor SLP. Além disso, a hiperexpressão de OCT1 apresentou valor preditivo de prognóstico para a SG e SLP em pacientes com LDGCB tratados com R-CHOP / The diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma subtype in developing countries. However, despite its prevalence and importance, there are still few publications showing the epidemiological data of the Brazilian population. Knowing the prognostic factors is imperative to identify patients supposed to better respond to treatment, as well as to allow their therapeutic individualization. Some studies have shown that patients with the same International Prognostic Index (IPI) may present different survival rates, thus justifying the need to identify new prognosis biomarkers. The aim of this study was to assess the prognostic impact of the genes BCL2, MDR1 and OCT1 and their respective proteins and t (14; 18) translocation on the complete response (CR), overall survival (OS), disease-free survival (DFS) and progression-free survival (PFS) of patients with DLBCL. We retrospectively assessed 98 patients with de novo DLBCL treated with R-CHOP. The gene expression was assessed through real-time PCR using RNA extracted from paraffin samples. The protein expression was assessed through the immunohistochemistry method. The median age was 54.5 years; 49 patients (50%) were men. Sixty-four patients (85.3%) had CR and median follow-up 2.66 years. The median expression of BCL2, MDR1 and OCT1 was 6.27; 0 and 24.49, respectively. We did not find the prognostic impact of the BCL2 gene expression on CR (p = 0.277), OS (p = 0.068) and on DFS (p = 0.860). However, the expression of BCL2 >= the median was associated with the lower PFS (p = 0.040). We found association between OCT1 gene expression >= the median and worse prognosis for OS (p = 0.010) and PFS (p = 0.016). However, we did not find the prognostic impact of OCT1 expression on CR (p = 0.464) and DFS (p = 0.717). There was no association between the MDR1 gene expression and the BCL-2, Pg-p and OCT-1 proteins, and the patients\' prognosis regarding CR, OS, DFS and PFS. The number of extranodal sites (p = 0.004 and p = 0.005), the clinical status (p <0.001 for both), the IPI (p < 0.001 for both) and DHL levels (p = 0.010 and p = 0.008) presented PFS, respectively. When the patients were stratified by stage, IPI and age, the group with OCT1 expression at the median and intermediate-to-high or high-risk IPI had worse OS results (p = 0.048) and the patients in the age group >= 60 years and expression of OCT1 >= the median presented worse prognosis for OS and PFS (p = 0.025 for both). Therefore, the MDR1 expression had no impact on the prognosis of DLBCL carriers. However, the expression of the BCL2 gene >= the median was associated with lower PFS. In addition, the OCT1 hyperexpression presented a predictive prognosis value for OS and PFS in patients with DLBCL treated with R-CHOP
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Linfoma difuso de grandes células B, SOE de novo: significado prognóstico de algoritmos e biomarcadores imuno-histoquímicos em pacientes tratados com esquema CHOP-simile e rituximab / Diffuse large B-cell lymphoma, NOS de novo: prognostic significance of immunohistochemical algorithms and biomarkers in patients treated with rituximab plus a CHOP-like regimen

Paula, Henrique Moura de 26 July 2016 (has links)
INTRODUÇÃO: O linfoma difuso de grandes células B, sem outras especificaçoes (LDGCB, SOE) é uma neoplasia agressiva caracterizada pela heterogeneidade morfológica, imunofenotípica e molecular, porém o atual tratamento padrão utilizando imunoquimioterapia (R-CHOP) não considera tal diversidade. Há percentual significativo de pacientes que são refratários à terapia de primeira linha e alguns que apresentam recidiva precoce ou tardia, os quais representam as vítimas desta doença. O estudo imuno-histoquímico (IHQ), que é um método simples e universalmente disponível, vem sendo utilizado para reconhecer a diversidade biológica do LDGCB, SOE, identificando biomarcadores e subgrupos distintos da doença, que poderiam predizer a resposta terapêutica ao tratamento padrão e apontar possíveis candidatos a novas estratégias terapêuticas. OBJETIVOS: Este estudo avalia o valor prognóstico de cinco algoritmos para classificação do LDGCB segundo a célula de origem (COO) e da expressão de três biomarcadores (BCL2, CD30 e MYC) tendo como endpoint a sobrevida global. MÉTODOS: Foi realizado estudo retrospectivo com setenta e nove pacientes com LDGCB,SOE de novo tratados com imunoquimioterapia padrão, estadiados e acompanhados protocolarmente. Os casos foram classificados como subgrupo célula B centrogerminativa símile (GCB) ou como subgrupo célula B não-centrogerminativa símile (NGCB), de acordo com três algoritmos IHQ (Hans, Choi, e Visco-Young) pareados com estudo do perfil de expressão gênica (PEG) e dois algoritmos IHQ não-PEG pareados (Muris e Nyman). Foi estimado o valor prognóstico destes algoritmos e também avaliado a concordância entre eles. O valor prognóstico da expressão do BCL2, CD30 e MYC utilizando IHQ também foi analisado. RESULTADOS: Os algoritmos IHQ PEG pareados revelaram maior concordância entre si, porém nenhum deles revelou força prognóstica. A expressão do CD30 mostrou tendência a melhor prognóstico, porém a expressão de BCL2 e MYC avaliados isoladamente não revelaram impacto prognóstico. Contudo, a coexpressão do BCL2 e MYC, denominado como fenótipo linfoma duplo-expressor (LDE), revelou-se importante marcador prognóstico desfavorável. Foram identificados três subgrupos de risco baseado no fenótipo LDE e o Índice Prognóstico Internacional (IPI). CONCLUSÃO: Em pacientes com LDGCB, SOE de novo tratados com esquema terapêutico padrão, a pesquisa da expressão do fenótipo LDE é mais relevante do ponto vista prognóstico que a classificação em subgrupo GCB ou NGCB. Além disso, a expressão do CD30 pode ser relevante tanto para identificar subgrupo com tendência a melhor prognóstico como para identificar possíveis candidatos a nova terapia alvo / BACKGROUND: Diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS) is an aggressive neoplasm characterized by morphological, phenotypic and molecular heterogeneity, but the current standard therapy using immunochemotherapy (R-CHOP) does not consider such diversity. There is a significant percentage of patients who are refractory to first-line therapy and those with early or late recurrence, whose represent the victims of this disease. Immunohistochemistry (IHC), a simple and universally available method, has been used to recognize the biological diversity of DLBCL, NOS, to identify biomarkers and distinct subgroups of the disease, which would predict the therapeutic response to standard treatment and point possible candidates for novel therapeutic strategies. OBJECTIVES: The current study was conducted to evaluate the prognostic value from five algorithms for classification of DLBCL based on cell of origin (COO) and the expression of three biomarkers (BCL2, CD30 and MYC) with overall survival (OS) as an endpoint. METHODS: We retrospectively evaluated seventy nine patients with de novo DLBCL, NOS treated with R-CHOP-like immunochemotherapy. The cases were assigned as germinal center B-cell like (GCB) or non-GCB subgroup (NGCB) according to five different IHC algorithms, including three algorithms based on gene expressing profile study (GEP), proposed by Hans, Choi, and Visco-Young, and two non-GEP based algoritms proposed by Muris, and Nyman. We evaluated their prognostic relevance and the concordance between these algorithms. The prognostic power of BCL2, CD30 and MYC expression were also assessed by IHC. RESULTS: None of the profiles assessed by IHC algorithms was able to predict overall survival (OS). The positive expression of CD30 showed a trend toward a better outcome. Neither the positive expression of BCL2 nor the positive expression of MYC were associated with outcome. However, the double-expressor lymphoma phenotype (DEL), represented by the concurrent expression of MYC and BCL2, exhibited a negative prognostic impact. Three different risk subgroups were identified based on the DEL phenotype and the International Prognostic Index (IPI) score. CONCLUSIONS: These data suggest that the DEL, rather than the cell of origin classification based on IHC, is a better predictor of OS in patients with DLBCL treated with R-CHOP-like immunochemotherapy. Besides, the CD30 expression may be a useful prognostic marker and a possible therapeutic target
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Targeting breast cancer with natural forms of vitamin E and simvastatin

Gopalan, Archana 13 July 2012 (has links)
Breast cancer is the second leading cause of death due to cancer in women. A number of effective therapeutic strategies have been implemented in clinics to cope with the disease yet recurrent disease and toxicity reduce their effectiveness. Hence, there is a need to identify and develop more effective therapies with reduced toxic side effects to improve overall survival rates. This dissertation investigates the mechanisms of action of two natural forms of vitamin E and a cholesterol lowering drug, simvastatin, as a therapeutic strategy in human breast cancer cells. Vitamin E in nature consists of eight distinct forms which are fat soluble small lipids. Until recently, vitamin E was known as a potent antioxidant but emerging work suggests they may be resourceful agents in managing a number of chronic diseases including cancer. Anticancer properties of vitamin E have been identified to be limited to the γ- and δ- forms of both tocopherols and tocotrienols. Gamma-tocopherol ([gamma]T) and gamma-tocotrienol ([gamma]T3) have both already been identified to induce death receptor 5 (DR5) mediated apoptosis in breast cancer cells. Studies here show that similar to [gamma]T3, [gamma]T induced DR5 activation is mediated by c-Jun N-terminal kinase/C/EBP homologous protein (JNK/CHOP) proapoptotic axis which in part contributed to [gamma]T mediated dowregulation of c-FLIP, Bcl-2 and Survivin. Also, both agents activate de novo ceramide synthesis pathway which induces JNK/CHOP/DR5 proapoptotic axis and downregulates antiapoptotic factors FLICE inhibitory protein (c-FLIP), B-cell lymphoma 2 (Bcl-2) and Survivin leading to apoptosis. Simvastatin (SVA) has been identified to display pleiotropic effects including anticancer effects but mechanisms responsible for these actions have yet to be fully understood. In this dissertation, it was observed that simvastatin induced apoptosis in human breast cancer cells via activation of JNK/CHOP/DR5 proapoptotic axis and down regulation of antiapoptotic factors c-FLIP and Survivin which are in part dependent on JNK/CHOP/DR5 axis. The anticancer effects mediated by simvastatin can be reversed by exogenously added mevalonate and geranylgeranyl pyrophosphate (GGPP), implicating the blockage of mevalonate as a key event. Furthermore, work has been done to understand the factors responsible for drug resistance and identify therapeutic strategies to counteract the same. It was observed that development of drug resistance was associated with an increase in the percentage of tumor initiating cells (TICs) in both tamoxifen and Adriamycin resistant cells compared to their parental counterparts which was accompanied by an increase in phosphorylated form of Signal transducer and activator of transcription 3 (Stat3) proteins as well as its downstream mediators c-Myc, cyclin D1, Bcl-xL and Survivin. Inhibition of Stat3 demonstrated that Stat3 and its downstream mediators play an important role in regulation of TICs in drug resistant breast cancer. Moreover, SVA, [gamma]T3 and combination of SVA+[gamma]T3 has been observed to target TICs in drug resistant human breast cancer cells and downregulate Stat3 as well as its downstream mediators making it an attractive agent to overcome drug resistance. From the data presented here, the mechanisms responsible for the anticancer actions of [gamma]T, [gamma]T3 and SVA have been better understood, providing the necessary rationale to test these agents by themselves or in combination in pre-clinical models. / text

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