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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.
31

Mitochondrial DNA heteroplasmy in radiation induced myelodysplasia and leukaemia

La Cock, Charles JR January 1996 (has links)
Thesis (MTech(Medical Technology))--Cape Technikon, Cape Town, 1996 / Haematol.ogical defects observed in cl.onal deletions of mtDNA and the inhibition of mitochondrial function by benzene and chloramphenicol., suggest a role for mtDNA in the pathogenesis of radiation - induced preleukaemia (MDS). The fact that leukaemia cell.s contain abnormal mitochondria and abnormally structured mtDNA, makes it reasonable to assume mtDNA mutations could be central to the pathogenesis of both MDS and l.eukaemia. It was decided to examine MDS patients for the presence of mtDNA length mutations (dimers and cocantameres). Such topol.ogical forms have already been reported in the literature in association with human leukaemia. These steric considerations suggest that mtDNA dimers are probably non-functional due to supercoil.ing. Thus, it was felt that a progressive accumulation of non-functional dimers in the haematopoietic compartment could account for many of the cl.inical. features associated with MDS. Transmission electron microscopy was used to examine haematopoietic mtDNA in the bone marrow of six patients with MDS. Abnormal mtDNA dimer formation was found in al.l instances. The proportional. number of these dimers were found to roughly correlate with the Myeloid/ Erythroid cell. ratio in the bone marrow, and it appeared likely that the dimers were generated in the myeloid compartment during early MDS. Control.l.ed radiation studies were performed on 20 wistar rats in an attempt to elucidate the approximate time when abnormal mtDNA dimer formation occurred, fol.l.owing fractionated gamma or gamma-neutron irradiation. Gamma-irradiated rats demonstrated abnormal mtDNA dimer formation at the time hypoplastic marrow recovery was first observed.
32

Influência de probióticos no desempenho produtivo e fisiológico de rã-touro Rana catesbeiana Shaw, 1802 /

Dias, Danielle de Carla. January 2006 (has links)
Resumo: Foi avaliado o efeito de dois probióticos adicionados à ração comercial (40%PB), no desempenho produtivo e fisiológico de rã-touro Rana catesbeiana . O teste foi conduzido com duas doses de cada probiótico (5g/kg e 10g/kg de alimento) mais um grupo controle com três réplicas simultâneas, totalizando 5 tratamentos. Foram avaliados o ganho de peso (GP), a conversão alimentar (CA), as análises hematológicas, como contagem diferencial de leucócitos, número de eritrócitos, contagem total de leucócitos e de trombócitos, determinação da porcentagem de hematócrito, determinação da taxa de hemoglobina, os índices hematimétricos absolutos (VCM, HCM e CHCM) e análises imunológicas como capacidade fagocítica e índice fagocítico. Os resultados mostraram que os probióticos produziram efeito no ganho de peso de Rana catesbeiana até atingirem 200g e também na conversão alimentar, influenciando somente nos números absolutos dos basófilos nos parâmetros hematológicos dos animais. As análises imunológicas mostraram que os probióticos apresentaram efeito imunoestimulador. Palavras-chave: ranicultura, análises hematológicas, análises imunológicas. / Abstract: It was evaluated the effect of two probiotics added in the commercial ration (40%CP), in the productive and physiological performance of bullfrog, Rana catesbeiana. The test was lead with two doses of each probiotic (5g/Kg and 10g/Kg of food) plus a control group with three repetictions totalizing 5 treatments. Was evaluated the weight gain, feed conversion, hematological analyses as differential counting of leucocytes, counting of erytrocyte's number, total counting of leucocytes and trombocytes, determination of the hematocryts, and haemoglobin tax, absolute hematimetrycs indices (MCV, MCH and MCHC) and imunological analyses as fagocytical capacity and fagocytic index. The results had shown that the probiotics produced effect in the weight gain of Rana catesbeiana until reaching 200g, and in the feed conversion, only influencing in the absolute numbers of the basophils in the hematological parameters of the animals. The imunological analyses had shown that the probiotics had presented imunostimulator effect. / Orientador: Marta Verardino De Stéfani / Coorientador: Cláudia Maris Ferreira / Banca: Maria José Tavares Ranzani de Paiva / Banca: Fernando Corleto Maiorino / Mestre
33

Cuidados de enfermagem prestados a pacientes onco-hematólogos submetidos a altas doses de quimioterapia / Nursing care towards onco-haematological patients to undergo high doses of chemotherapy.

Viviane Dias da Silva Carlucci 19 September 2012 (has links)
Os pacientes onco-hematológicos submetidos a altas doses de quimioterapia sejam para tratamento de suas doenças de base ou para realização do transplante de células-tronco hematopoéticas (TCTH) sofrem com diversos efeitos adversos. Entre esses efeitos estão a neutropenia febril, mucosite, distúrbios do sono, depressão, ansiedade, fadiga física e mental e diminuição da capacidade do estado funcional do paciente. Neste contexto, a equipe de enfermagem tem papel fundamental na avaliação e implementação dos cuidados específicos para essa clientela. Trata-se de uma revisão integrativa da literatura cujo objetivo foi identificar, avaliar e sintetizar o conhecimento relacionado aos cuidados de enfermagem prestados aos pacientes onco-hematológicos adultos submetidos a altas doses de quimioterapia seguida ou não do TCTH. As bases de dados Pubmed/ Medline, Cinahl, Lilacs e Biblioteca Cochrane foram selecionadas para a busca dos estudos primários indexados, nos últimos 10 anos. Os descritores controlados foram delimitados para cada uma das bases de dados. Dos 725 estudos localizados e considerando os critérios seleção adotados, 45 estudos foram selecionados para leitura na íntegra e 13 estudos primários foram incluídos na revisão integrativa. Para extração dos dados foi utilizado um instrumento validado. A análise dos dados foi descritiva. Os estudos primários incluídos foram divididos nas seguintes categorias temáticas: fadiga e atividade física, segurança do paciente e cuidados com mucosite. De acordo com os estudos primários avaliados pode-se observar que as intervenções propostas para o cuidado dos pacientes submetidos a altas doses de quimioterapia seguidos ou não ao TCTH foram, em sua maioria, para minimizar ou promover a diminuição dos efeitos adversos relacionados ao tratamento. Os efeitos adversos apresentados causam ao paciente prejuízo no estado funcional, nutricional, na qualidade de sono e repouso, qualidade de vida. Cabe ao enfermeiro implementar um conjunto de estratégias para ter um controle da situação atual do paciente para poder intervir no momento necessário adequado, a fim de evitar complicações. / Onco-haematological patients to undergo high doses of chemotherapy for disease treatment as well for hematopoietic stem cell transplantation (TCTH) suffer with adverse side effects. Among these effects are febrile neutropenia, mucositis, sleep disorder, depression, anxiety, physical and mental tiredness and decrease of the patient\'s functional capacity. In this text, the nurse team has important role over the assessment and implementation of specific care towards these kinds of patients. Referring to integrative literature review which purpose is identify, assess and summarize the understandings related to nursing care towards adult onco- haematological patients who underwent high doses of chemotherapy followed or not to TCTH. Data base Pubmed/ Medline, Cinahl, Lilacs and Cochrane Library have been selected to search the indicated primary studies over the past 10 years. The controlled describers have been delimited for each of data base. From over the 725 found studies and considering the defined rules, 45 studies have been selected for full reading and 13 primary studies have been included over the integrative review. For data pull out it was used a validated mechanism. Data analysis was descriptive. The primary studies have been divided into the following categories: tiredness and physical activity, patient safety and mucositis care. According to the assessed primary studies it can be noticed that the offered intervention for patient\'s care that underwent to high doses of chemotherapy followed or not to TCTH were, in majority, to minimize or promote the decrease of the adverse side effects related to the treatment. The presented side effects caused damage to the patient functional condition, nutritional condition, sleep quality and rest, quality of life. The nurse is in charge of implementing a strategy to obtain the control of the current situation of the patient in order to interfere at the adequate moment to avoid any complications.
34

Lethal concentration (LC50-96h) and sublethal effects of un-ionized ammonia on haematological para parameters of fingerlings tambacu (Colossoma macropomum x Piaractus mesopotamicus) / ConcentraÃÃo letal mÃdia (CL50-96h) e efeitos subletais da amÃnia nÃo ionizada sobre parÃmetros hematolÃgicos de alevinos de tambacu (Colossoma macropomum fÃmea x Piaractus mesopotamicus macho)

FabrÃzia da Silva Quaresma 22 February 2016 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / A amÃnia à um composto tÃxico para os organismos aquÃticos e em elevadas concentraÃÃes na Ãgua pode causar diversas alteraÃÃes no animal. Dessa forma, torna-se importante determinar o limite de tolerÃncia dos animais aquÃticos cultivados à essa substÃncia. Sendo assim, o objetivo do trabalho foi determinar a concentraÃÃo letal mÃdia (CL50-96h) da amÃnia nÃo ionizada (NH3) em alevinos de tambacu (Colossoma macropomum x Piaractus mesopotamicus), em teste de toxicidade aguda e avaliar os efeitos de concentraÃÃes subletais atravÃs da anÃlise de parÃmetros hematÃlogicos. No teste de toxicidade aguda, os alevinos foram expostos à amÃnia, nas concentraÃÃes de: 0,09 (controle); 0,54; 1,23; 2,52; 3,44 e 3,66 mg L-1 NH3, que foram obtidas a partir da aplicaÃÃo de NH4Cl. O teste teve duraÃÃo de 96h e as mortalidades foram registradas ao longo desse perÃodo. A CL50 foi determinada pelo mÃtodo estatÃstico Trimmed Spearman Karber. No teste de exposiÃÃo subletal à amÃnia, utilizou-se as concentraÃÃes: 0,04 (controle), 0,19 e 0,35 mg L-1 NH3. Para anÃlise dos parÃmetros hematolÃgicos, foram realizadas coletas de sangue antes da adiÃÃo de NH4Cl (tempo zero) e apÃs 96h de exposiÃÃo. Os parÃmetros hematolÃgicos analisados foram: hematÃcrito (Ht), taxa de hemoglobina (Hb), nÃmero de eritrÃcitos (RBC), volume corpuscular mÃdio (VCM), hemoglobina corpuscular mÃdia (HCM) e concentraÃÃo de hemoglobina corpuscular mÃdia (CHCM). Os dados dos parÃmetros hematolÃgicos foram submetidos à anÃlise de variÃncia (ANOVA) e quando houve diferenÃa significativa entre os tratamentos, as mÃdias foram comparadas duas a duas atravÃs do teste de Tukey (α=0,05). A CL50-96h da amÃnia nÃo ionizada (NH3) para alevinos do hÃbrido tambacu foi 1,63 mg L-1. ApÃs exposiÃÃo de 96h a 0,35 mg L-1 NH3, os peixes apresentaram reduÃÃes significativas no Ht e VCM e aumento significativo na CHCM. Jà Hb, RBC e HCM nÃo diferiram significativamente entre os tratamentos e o tempo 0. A exposiÃÃo de alevinos de tambacu por curto perÃodo de tempo a 0,19 mg L-1 de amÃnia nÃo ionizada (NH3) nÃo causa alteraÃÃes significativas nos parÃmetros hematolÃgicos desses peixes. / Ammonia is a toxic compound to aquatic organisms and at high concentrations in the water can cause various changes in the animal. Therefore, it becomes important to determine the tolerance of farmed aquatic animals for that substance. Thus, the aim of this study was to determine the median lethal concentration (LC50-96h) of un-ionized ammonia (NH3) in fingerlings tambacu (Colossoma macropomum x Piaractus mesopotamicus) in acute toxicity test and evaluate the effects of concentrations sublethal through the analysis of hematological parameters. In the acute toxicity test, the fingerl ings were exposed to ammonia at concentrations of: 0,09 (control); 0,54; 1,23; 2,52; 3 ,44 and 3,66 mg L-1NH3, which were obtained from the application of NH4Cl. The test lasted 96 hours and mortalities were recorded over that period. The LC50 was determin ed by statistical method Trimmed Spearman Karber . In sublethal exposure to ammonia test concentrations used were : 0,04 (control), 0,19 and 0,35mg L-1NH3.For analysis of hematological parameters, blood samples were collected before the addition of NH4Cl(timezero) and after 96 hours of exposure.The hematological parameters analyzed were: hematocrit ( Ht), hemoglobin(Hb), red blood cell count(RBC) mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration(MCHC). Data hematological parameters were subjected to analysis of variance (ANOVA) and when there was a significant difference between treatments , the averages were compared in pairs through the Tukey's HSD test (α=0,05).LC50-96h of theun - ionized ammonia (NH3) to fingerlings the hybrid tambacu was 1,63m g L-1. After 96h exposure to 0,35 mg L-1NH3, fish showed significant reductions in hematocrit and the MCV and significant increase in MCHC. Already Hb,RBC and MCH did not differ significantly between treatments and time 0. The exposure to fingerlins tambacu for short period to 0,19 mg L -1 of un-ionized ammonia (NH3) does not cause significant changes in hematological parameters of these fish.
35

Avaliação hematológica, bioquímica e eletrocardiográfica de cães com diferentes neoplasias tratados com doxorrubicina / Hematological, biochemical and electrocardiographic abnormalities in dogs with different malignancies treated with doxorubicin

Neuwald, Elisa Barp January 2009 (has links)
O quimioterápico doxorrubicina, pertencente à família das antraciclinas, é um dos agentes antineoplásicos mais utilizados na medicina veterinária, no tratamento de uma variedade de sarcomas e carcinomas. No entanto, o uso da doxorrubicina está associado à presença de toxicidade, envolvendo principalmente anormalidades hematológicas, gastrointestinais e cardiovasculares, podendo induzir uma cardiomiopatia irreversível. O objetivo deste trabalho foi avaliar estas manifestações tóxicas, bem como as alterações hematológicas, bioquímicas e eletrocardiográficas em 25 cães com diferentes neoplasias tratados com doxorrubicina (30 mg/m² a cada 21 dias por três doses). Além disso, buscou-se avaliar as troponinas cardíacas I e T como marcadores cardíacos para a detecção precoce de cardiomiopatia induzida pela quimioterapia. Amostras de sangue foram coletadas antes de cada administração de doxorrubicina, sete dias após (nadir) e um mês depois do término do tratamento. As toxicidades hematológicas e gastrointestinais foram as alterações mais frequentes, ocorrendo em 22 (88%) e 19 (76%) cães, respectivamente. Neutropenia severa ocorreu em 25% dos casos, enquanto que não foram observados casos de trombocitopenia severa. Os sinais mais comumente observados foram vômito, anorexia e diarréia, os quais foram responsáveis, em parte, pelo aparecimento de hipoalbuminemia e reduções nas concentrações séricas de potássio, cálcio e proteína total. Observou-se também aumento nas concentrações séricas de proteína C reativa o que, assim como a diminuição da albumina, deve ser consequência de uma resposta de fase aguda induzida pela administração da doxorrubicina. Sepse foi incomum, ocorrendo em menos de 2% dos casos, e nenhum animal veio a óbito por complicações da quimioterapia. Sinais clínicos de cardiomiopatia não foram observados, porém aumentos nas troponinas cardíacas I e T ocorreram em 18 (72%) e 5 (20%) cães, respectivamente. Todos os cães com altas concentrações de troponina cardíaca T também apresentavam altas concentrações de troponina cardíaca I. Arritmias foram detectadas em 15 (60%) animais, mas não houve correlação com o aumento das troponinas cardíacas séricas e a presença de arritmias. No entanto, os cães que desenvolveram complexos atriais e ventriculares prematuros no eletrocardiograma apresentaram altas concentrações das troponinas. Este estudo demonstrou a ocorrência de alterações hematológicas e gastrointestinais toleráveis em cães recebendo doxorrubicina como único agente quimioterápico. Além disso, as concentrações séricas de troponinas cardíacas I e T podem ser utilizadas na detecção precoce de lesão miocárdica induzida pela doxorrubicina em cães. / The anthracicline chemotherapic doxorubicin is one of the anticancer agents most used in veterinary medicine to treat a variety of sarcomas and carcinomas. However, doxorubicin is associated with several toxicities, including hematological, gastrointestinal and cardiac abnormalities, and it can induce cardiomyopathy in dogs. The purpose of this study was to evaluate these toxic manifestations, as well as hematological, biochemical and electrocardiographic alterations in 25 dogs with spontaneously occurring malignant tumors treated with doxorubicin (30 mg/m² each 21 days during three doses). Moreover, cardiac troponins I (cTnI) and T (cTnT) were evaluated to determine cardiac-specific markers for predict cardiomyopathy-induced by chemotherapy. Blood samples were collected before each doxorubicin administration, seven days after each dose (nadir) and one month after the end of therapy. Hematological and gastrointestinal toxicities were the most frequent abnormalities observed and occurred in 22 (88%) and 19 (76%) dogs, respectively. Severe neutropenia occurred in 25% of the animals, while severe thrombocytopenia was not observed. Vomiting, anorexia and diarrhea occurred frequently, and were responsible, in part, for the presence of hypoalbuminemia and decreases in potassium, calcium and total protein serum concentrations. Increases in C reactive protein were also observed, wich together with decreases in albumin, may be due to acute phase response induced by doxorubicin. The frequency of sepsis was less than 2% and any animal died because of therapy complications. Signs of cardiomyopathy were not observed, however, increases in serum concentrations of cTnI and cTnT were found in 18 (72%) and 5 (20%) dogs, respectively. All dogs with high cTnT had high cTnI concentrations. Arrhythmias were detected in 15 (60%) animals, and it was not correlated with increases in cardiac troponins. Those dogs that developed atrial and ventricular premature complexes in the electrocardiogram showed increases in cTnI concentrations. In conclusion, doxorubicin used as single agent produced tolerable hematological and gastrointestinal toxicosis. Furthermore, cTnI and cTnT measurement can be used for early detection of myocardial injury caused by doxorubicin chemotherapy in dogs.
36

Hematological and biochemical parameters evaluation of healthy volunteers of the Clinical Pharmacology Unit of UFC / AvaliaÃÃo dos parÃmetros hematolÃgicos e bioquÃmicos de voluntÃrios sadios da Unidade de Farmacologia ClÃnica da UFC

Isabele Bessera Santos Gomes 20 June 2005 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Os valores de referÃncia de exames laboratoriais sÃo definidos com base em critÃrios estatÃsticos para uma amostra aleatÃria de indivÃduos. Os parÃmetros de referÃncia publicados sÃo provenientes de uma variedade de amostras, incluindo doadores de sangue, participantes de exames admissionais e voluntÃrios normais que fazem exames de rotina para ensaios clÃnicos. Esta pesquisa à do tipo documental com abordagem quantitativa. A amostra foi constituÃda por 1.947 exames laboratoriais dos voluntÃrios sadios, de ambos os sexos, com idade mÃdia de 25 anos, que participaram de ensaios clÃnicos na UNIFAC, entre os anos de 1999 e 2003. Para a realizaÃÃo do estudo, foram colhidos dos prontuÃrios as seguintes informaÃÃes: dados de identificaÃÃo do voluntÃrio, alÃm dos parÃmetros hematolÃgicos e bioquÃmicos. Foram investigados setenta e cinco ensaios clÃnicos, tendo os resultados demonstrado diferenÃa estatÃstica entre os sexo, para a maioria dos parÃmetros analisados. As faixas de referÃncia foram calculadas pelo mÃtodo dos percentis, sendo encontrado os seguintes valores para a anÃlise hematolÃgica para mulheres e homens, respectivamente: eritrÃcitos - de 3,9 a 5,0 milhÃes/mm3 e 4,4 a 5,7 milhÃes/mm3; hemoglobina - de 14,8 a 15,3 g/dL e 13,6 a 16,9 g/dL; leucÃcitos - de 4.400 a 10.500/ mm3 e 4.200 a 10.100/mm3; plaquetas â de 165.000 a 397.000/ mm3 e 155600 a 354400/ mm3. Jà para os parÃmetros bioquÃmicos, verificaram-se os seguintes valores para mulheres e homens, respectivamente: creatinina - de 0,5 a 0,9 mg/dL e 0,7 a 1,2 mg/dL; glicose - de 69 a 96 mg/dL e 71 a 100 mg/dL; colesterol - de 118 a 224 mg/dL e 112 a 219 mg/dL; triglicerÃdeos - de 38,0 a 171 mg/dL e 42 a 197 mg/dL. Os nossos achados sugerem que os valores de referÃncia dos parÃmetros investigados, para a populaÃÃo metropolitana de Fortaleza, sejam redefinidos como aqueles incluÃdos no intervalo entre os percentis 2,5o e 97o, os quais correspondem a 95% da distribuiÃÃo total dos valores de cada parÃmetro. / The values of reference of laboratorial parameters are defined on the basis of statistical criteria for a random sample of individuals. The published parameters of reference are proceeding from a variety of samples, including blood donors, participants of job admission examinations and normal voluntaries that are submitted to routine examinations for clinical assays. This research is of the documentary type with quantitative approach. The sample was constituted by 1.947 laboratorial parameters of healthy volunteers, of both genders, with average of 25 years, which had participated of clinical assays in the Clinical Pharmacological Unit (UNIFAC â UFC), between the years of 1999 and 2003. For the accomplishment of the study, the following information had been obtained from case report files: identification of the volunteer, besides the hematological and biochemical parameters. Seventy five clinical assays have been investigated. The results demonstrated statistical differences between the genders, for the majority of the analyzed parameters. The normal reference intervals have been calculated by the method of percentiles, being found the following values for the hematological analysis for women and men, respectively: erytrocytes â from 3.9 to 5.0 millions/mm3 and from 4.4 to 5.7 millions/mm3; hemoglobin â from 14.8 to 15.3 g/dL, and from 13.6 to 16.9 g/dL; leukocytes â between 4.400 and 10.500/mm3, and between 4.200 and 10.100//mm3; platelets â from 165.000 to 397.000/mm3, and from 155.600 to 354.400/mm3. For the biochemical parameters, there were found the following values for women and men, respectively: creatinine â from 0.5 to 0.9 mg/dL, and from 0.7 to 1.2 mg/dL; glucose â between 69 and 96 mg/dL, and between 71 and 100 mg/dL; cholesterol â between 118 and 224 mg/dL, and between 112 and 219 mg/dL; triglycerides â from 38 to 171 mg/dL, and from 42 to 197 mg/dL. Our findings suggest that the reference values of investigated parameters, for the metropolitan population of Fortaleza, must be redefined as that enclosed in the interval between the 2.5 and 97, which correspond to 95% of the total distribution of the values of each parameter.
37

Etude des mécanismes de coopération oncogénique impliquant TET2 dans les hémopathies malignes : exemples des coopérations avec DNMT3A et EZH2 / Mutational Cooperativity Involving TET2 in Hematological Disorders : Emphasis on DNMT3A and EZH2

Scourzic, Laurianne 26 October 2015 (has links)
Les protéines de la famille TET catalysent l'oxydation des 5-méthylcytosines (5mC) en 5-hydroxyméthylcytosines (5hmC) et jouent ainsi un rôle dans la régulation épigénétique de la transcription et dans le processus de déméthylation de l'ADN. Les interactions entre la méthylation de l'ADN et les autres marques épigénétiques sont encore mal connues.Des mutations inactivatrices du gène TET2 ont été décrites dans les hémopathies myéloïdes et lymphoïdes et l'inactivation conditionnelle (cKO) de ce gène évaluée chez la souris a permis d'identifier de multiples anomalies de l'hématopoïèse, ainsi que le développement tardif d'hémopathies myéloïdes. Cette latence importante suggère la nécessité d'évènements oncogéniques coopératifs pour la transformation hématopoïétique. Chez l'Homme, les mutations de TET2 sont observées en association avec de nombreuses autres mutations, et en particulier avec des mutations du gène DNMT3A impliqué dans la méthylation de novo des cytosines de l'ADN, et avec des mutations du gène EZH2 responsable de methylation de la lysine 27 de l'histone H3. Nous avons testé fonctionnellement ces associations en utilisant des modèles murins.L'utilisation d'un modèle de transplantation de moelle osseuse nous a permis d'identifier une coopération de l'inactivation de Tet2 et du mutant DNMT3AR882H dans la transformation des lignées myéloïdes et lymphoïde T, correspondant aux hémopathies humaines porteuses de ces mutations. Dans la transformation lymphoïde, nos données indiquent que la dérégulation de la méthylation entraine une surexpression du gène NOTCH1 et de l'activité de la voie de signalisation correspondante.L'analyse de souris invalidées de manière conditionnelle pour Tet2 et Ezh2 a montré que les souris correspondantes meurent d'aplasie médullaire, dont l'origine est imputée à la disparition de cellules souches hématopoïétiques capables de reconstituer l'hématopoïèse à long terme (LT-HSC). Ezh2 et Tet2 ont donc des rôles primordiaux dans le maintien de l'autorenouvellement des cellules souches hématopoïétiques, dont les mécanismes moléculaires, génétiques et épigénétiques restent à définir. / TET family proteins catalyzing the conversion of 5-methylcytosines (5mC) into 5-hydroxymethylcytosines (5hmC) are crucial for epigenetic regulation of transcription and for DNA demethylation. Interactions between DNA methylation and other epigenetic marks are not fully understood.TET2 inactivating mutations have been identified in both myeloid and lymphoid malignancies. The conditional inactivation (cKO) of this gene in mice highlights pleiotropic hematopoietic abnormalities as well as myeloid transformation at late stages. This latency suggest cooperativity between Tet2 and other oncogenic events during transformation. Human TET2 mutations are frequently found associated with other mutations, and more particularly with mutations in DNMT3A, involved in de novo methylation of cytosines and with mutations in EZH2, responsible for lysine 27 of histone H3 methylation. We decided to functionally assess these mutation associations in mice.Bone marrow transplantation of Tet2 inactivated and DNMT3AR882H mutated cells allowed us to identify myeloid and T-cell transformations, corresponding to human hematological disorders harboring these mutations. Our results on T-cell transformations clearly demonstrate that the deregulation of methylation leads to NOTCH1 overexpression and activation of the corresponding signaling pathway.Analyses of Tet2 and Ezh2 inactivated mice show that these Ezh2 Tet2 mice succumb to bone marrow exhaustion, attributed to long term hematopoietic stem cells (LT-HSC) disappearance. Ezh2 and Tet2 show major roles in LT-HSC maintenance whose molecular, genetic and epigenetic mechanism remains to be investigated.
38

Potential of Plant-Derived Natural Products in the Treatment of Leukemia and Lymphoma

Lucas, David M., Still, Patrick C., Bueno Pérez, Lynette, Grever, Michael R., Douglas Kinghorn, A. 23 July 2010 (has links)
Hematologic malignancies account for a substantial percentage of cancers worldwide, and the heterogeneity and biological characteristics of leukemias and lymphomas present unique therapeutic challenges. Although treatment options exist for most of these diseases, many types remain incurable and the emergence of drug resistance is pervasive. Thus, novel treatment approaches are essential to improve outcome. Nearly half of the agents used in cancer therapy today are either natural products or derivatives of natural products. The e l,normous chemical diversity in nature, coupled with millennia of biological selection, has generated a vast and underexplored reservoir of unique chemical structures with biologic activity. This review will describe the investigation and application of natural products derived from higher plants in the treatment of leukemia and lymphoma and the rationale behind these efforts. In addition to the approved vinca alkaloids and the epipodophyllotoxin derivatives, a number of other plant compounds have shown promise in clinical trials and in preclinical investigations. In particular, we will focus on the discovery and biological evaluation of the plant- derived agent silvestrol, which shows potential for additional development as a new therapeutic agent for B-cell malignancies including chronic lymphocytic leukemia.
39

Malyglycemia and health outcomes in hospitalized patients with acute myleoid leukemia

Storey, Susan 09 April 2015 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Acute Myeloid Leukemia (AML) is the most common hematologic malignancy. Malglycemia is a disorder of glucose metabolism and includes hyperglycemia, hypoglycemia and the combination of hyperglycemia and hypoglycemia. Malglycemia has been shown to occur frequently during hospitalization among critical care patients and has been associated with increased risk of sepsis and mortality. Little is known, however, about the prevalence and role of malglycemia on the health outcomes of AML patients hospitalized for initial induction therapy. Malglycemia may be of particular importance to the patient with AML because, researchers have found that malglycemia may promote cellular changes which facilitate the progression of cancer, alter treatment response, and attenuate immune response. The purpose of this study was to determine the prevalence of malglycemia (hyperglycemia, hypoglycemia or the combination) and to examine its role on a comprehensive set of health outcomes (neutropenic days, infection, and septicemia, and sepsis, induction hospital length of stay, complete remission and mortality) in AML patients hospitalized for initial induction therapy. A retrospective cohort study design was used. Records of 103 AML patients, hospitalized for initial induction chemotherapy were reviewed. Results of the study showed that 98% of the AML patients had at least one episode of hyperglycemia, with a prevalence rate of 33% over the entire induction inpatient hospitalization for this population. All patients noted with hyperglycemia also had hypoglycemia and thus, the prevalence rate of hypoglycemia alone could not be determined. Prevalence of the combination of hyperglycemia and hypoglycemia was 1.4 %. Although not statistically significant, a trend was noted for AML patients with hyperglycemia to experience more days with neutropenia, greater numbers of infection, sepsis, septicemia and death (mortality) than patients without hyperglycemia during induction treatment. Patients with the combination of hyperglycemia and hypoglycemia also experienced an increased risk of developing septicemia (p = .025) and sepsis (p =.057). Future studies with larger sample sizes are needed to confirm these findings.
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Gene Expression Profiling Identifies IRF4-associated Molecular Signatures in Hematological Malignancies

Wang, Ling, Yao, Zhi Q., Moorman, Jonathan P., Xu, Yanji, Ning, Shunbin 10 September 2014 (has links) (PDF)
The lymphocyte-specific transcription factor Interferon (IFN) Regulatory Factor 4 (IRF4) is implicated in certain types of lymphoid and myeloid malignancies. However, the molecular mechanisms underlying its interactions with these malignancies are largely unknown. In this study, we have first profiled molecular signatures associated with IRF4 expression in associated cancers, by analyzing existing gene expression profiling datasets. Our results show that IRF4 is overexpressed in melanoma, in addition to previously reported contexts including leukemia, myeloma, and lymphoma, and that IRF4 is associated with a unique gene expression pattern in each context. A pool of important genes involved in B-cell development, oncogenesis, cell cycle regulation, and cell death including BATF, LIMD1, CFLAR, PIM2, and CCND2 are common signatures associated with IRF4 in non-Hodgkin B cell lymphomas. We confirmed the correlation of IRF4 with LIMD1 and CFLAR in a panel of cell lines derived from lymphomas. Moreover, we profiled the IRF4 transcriptome in the context of EBV latent infection, and confirmed several genes including IFI27, IFI44, GBP1, and ARHGAP18, as well as CFLAR as novel targets for IRF4. These results provide valuable information for understanding the IRF4 regulatory network, and improve our knowledge of the unique roles of IRF4 in different hematological malignancies.

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