• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 783
  • 308
  • 189
  • 68
  • 61
  • 43
  • 28
  • 22
  • 17
  • 16
  • 12
  • 8
  • 6
  • 3
  • 3
  • Tagged with
  • 1668
  • 531
  • 401
  • 316
  • 307
  • 277
  • 228
  • 227
  • 199
  • 173
  • 153
  • 152
  • 127
  • 119
  • 116
  • 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.
401

Treatment of Akr Mouse Leukemia with Specific Rabbit and Mouse Antiserum

Dunkerley, Gary Beasley 08 1900 (has links)
This work is concerned with a study of the role of complement and antibodies in the serum of rabbits and of a non-susceptible strain of mice in the protection of Akr mice injected with active Akr tumor cells.
402

Factors associated with intensity of end-of-life care for patients with acute myeloid leukemia

Vaughn, Dagny 01 December 2020 (has links)
INTRODUCTION: Older patients with AML (> 60 years) often receive intensive EOL care including hospitalizations and chemotherapy close to death. Intensive EOL care has been shown to increase emotional and financial burdens for patients and families, while often not aligning with patients’ preferences. However, factors associated with the intensity of EOL care in this population are unknown. OBJECTIVES: There is a need to better understand the factors associated with intense EOL care, in hopes of providing more informed, high-quality EOL care in line with patient preferences and decreasing burdens associated with unnecessary healthcare. We aim to describe the associations between the intensity of EOL care, patient demographics, and baseline psychological distress in older patients with AML. METHODS: We conducted a secondary analysis of two supportive care studies including 168 deceased older patients with AML. We assessed patients’ demographics, quality of life (QOL) [Functional Assessment Cancer Therapy-Leukemia], and anxiety and depression symptoms [Hospital Anxiety and Depression Scale (HADS); Patient Health Questionnaire (PHQ-9)] at the time of diagnosis. We used multivariate logistic regression models to examine the association among demographic factors, patient-reported outcomes, and the following EOL care outcomes abstracted from the electronic health record: 1) hospitalizations in the last 7 days of life; 2) receipt of chemotherapy in the last 30 days of life; and 3) hospice utilization. RESULTS: The median age of the cohort was 69 (range 20-100), and the majority were males (63.7% 107/168). Overall, 66.7% (110/165) of patients were hospitalized in the last 7 days of life, 51.8% (71/137) received chemotherapy in the last 30 days of life, and 40.7% (70/168) utilized hospice services. In multivariate models, higher education (OR = 1.54, SE=0.24, P=0.006), and elevated depression symptoms [PHQ-9: OR=1.09, SE=0.04, P=0.028] at the time of diagnosis were associated with higher odds of being hospitalized in the last 7 days of life. In contrast, higher QOL at diagnosis [OR=0.98, SE=0.01, P=0.009] was associated with lower odds of being hospitalized in the last 7 days of life. Depression symptoms at the time of diagnosis as measured by the HADS was the only factor associated with the receipt of chemotherapy in the last 30 days of life [HADS-Depression: OR=1.10, SE=0.05, P=0.042]. Patients factors were not associated with hospice utilization. CONCLUSIONS: Older patients with AML who are more educated and report elevated depression symptoms and lower QOL at the time of diagnosis were more likely to receive intensive EOL care. These findings identify a population at the time of diagnosis of AML who are at higher risk for hospitalizations and chemotherapy use at the EOL and who may benefit from targeted supportive care interventions.
403

Functional characterization and multi-factor analysis of exhaustion in chronic lymphocytic leukemia T cells

Lee, Joanne Haeun January 2021 (has links)
Adequate cell production for adoptive cell transfer therapies such as Chimeric Antigen Receptor (CAR)-T cell therapy remains a critical barrier to treatment for indications that fail to achieve clinical success. One such disease is Chronic Lymphocytic Leukemia (CLL), a B-cell lymphoma with their characteristically exhausted T cells, marked by a progressive loss of the ability to secrete cytokines and proliferate, as well as an increase in the expression of checkpoint inhibitor molecules such as PD-1. The goal of this thesis is to characterize the functional differences or specific biomarkers within the CLL patient population that is indicative of the proliferation outcomes. Conventional clinical markers such as Rai stage or PD-1 expression alone were inadequate to describe the complex variability among patients. In order to better characterize exhaustion using microscopy-based cell function assays, we developed a sample sparing microscopy chamber that requires as little as 1000 cells per sample. The microscopy chambers were mass produced via injection molding, and made compatible with the antibody microcontact printing technique developed in the Kam lab. The chambers typically reduced cell usage per experiment by 20-fold. This reduction allowed us to measure IL-2 secretion, T cell arrest response to activating antibody patterns (pattern alignment), and motility of scarce human samples simultaneously from a single experiment. Results from these functional readouts along with other clinical markers were used as inputs for a multifactor exploratory analysis to cluster patients according to their functional similarities from the combination of responses in an unbiased manner. The resulting clusters based on the combination of the top 3 parameters IL-2, pattern alignment, and PD-1 resulted in better separation of patient groups and provided a basis for predicting max doubling outcomes from these inputs. We further used motility measurements as a way to understand initial T cell response to activation before the stop response, which was measured as pattern alignment previously. The time it takes for cells to come to a stop at the signal was most informative for translating T cell activation response to a stop response, and eventually to downstream effector functions of cytokine secretion and proliferation. The results of this work provide a powerful framework to describe different donors, and can be applied to cells from additional donors to guide future cell expansion studies.
404

Targeting T-cells to Acute Myeloid Leukemia with a Novel Bispecific Antibody Format

Burke, Alan Austin January 2022 (has links)
Treatment of acute myeloid leukemia, an aggressive hematopoietic malignancy of myeloid progenitors, has remained rather stagnant over the course of several decades. Infusions of cytarabine and anthracycline antibiotics have dominated the landscape of AML therapy, with minor changes to dosing schedule occasionally making slight adjustments to efficacy or tolerability. Improvements in prognosis have been bittersweet, with most progress seen in younger populations less likely to get the disease, and already more likely to achieve remission and to meet survival milestones. Much of this progress is attributed to other factors, such as improved supportive care and availability of hematopoietic stem cell and platelet transfusion. In most patients, occupying the 60-and-above demographic, improvements in survival have not been significant. In turn, the population impact of AML has changed little over time. While accounting for about one-third of total leukemia cases and one percent of total cancer cases, AML accounts for about one half of total leukemia deaths and two percent of total cancer deaths. Most advances straying away from standard treatment have been in important pathways that could be impactful in subsets of the overall AML patient population. Tyrosine kinases are implicated in numerous cancers including AML, with activity-enhancing mutations conferring growth advantages to malignant cells. About one-third of AML patients have mutations in one such kinase, FLT3, and may benefit from inhibitors to tyrosine kinases overall and from FLT3- specific agents. Mutations in isocitrate dehydrogenases highlight another subpopulation, about one-fifth of AML patients, who might benefit from emerging agents that inhibit these pathways from creating a leukemia-favoring environment in the bone marrow. Other pathways similarly implicated in numerous cancers including AML are being targeted with new agents that can benefit some AML patients, such as Hedgehog signaling and apoptotic regulation. Still, breakthroughs are needed that can help most AML patients, particularly in the cases of relapsed leukemia that occurs in most patients within a year or two after remission is achieved. CD33 is among a few molecular targets for AML, though it is just as ubiquitously expressed on healthy myeloid cells. Antibody-drug conjugates like Mylotarg have made progress in this approach, though hematopoietic toxicities have made treatment difficult in older populations. Clever techniques such as ablation of CD33 from healthy myeloid progenitors may be supportive in CD33-based approaches, and immunotherapy involving CD33-targeting is a rapidly growing research focus. This dissertation describes a new type of bispecific antibody that binds CD33 on AML and CD3 on cytotoxic T cells in a proof-of-concept study. Various formats for bifunctional molecules have been created and used clinically, including antibody-drug conjugates and bispecific antibodies that simultaneously engage antigens on two different types of cells. Those like the one described here, bispecific T-cell engagers, have typically taken the form of single-chain fusion proteins containing the variable regions binding to both antigens of interest. Other bispecific antibodies have imitated naturally-occurring immunoglobulin structures, boasting superior pharmacokinetics while facing steep obstacles in large-scale production. The single-chain fusions, easier to produce, can face difficulties in full engagement, with loss of function sometimes seen in fusion partners at the C-terminus. We propose a new format, believed to present two antigen-binding domains in N-terminal positions on a two-chain heterodimeric structure. Capitalizing on an elegantly designed system of hydrophobic cores and hydrogen-bonding networks generating an orthogonal heterodimer, we added an immunoglobulin hinge region to secure a permanently-bound heterodimer, and attached domains binding to CD3 and CD33. We hypothesized that this design, ensured to present its antibody components at N-termini, could bind two antigens at a distance appropriate for facilitating T cell cytotoxicity to AML. After expressing and purifying these proteins in mammalian cells, we demonstrated their ability to persist as a bispecific heterodimer. We showed in vitro that our bispecific heterodimers could bind both CD3+ and CD33+ cells, and that they bolstered T cell cytotoxicity to AML cell lines in a dose-dependent manner. Monomeric components bound only CD3+ or CD33+ cells depending on antibody variable domain present, and had no effect on T cell cytotoxicity. In a mouse model of minimal residual disease, T cells alone did not have a significant effect on the growth of AML, nor did they have an effect on overall survival. T cells with bispecific heterodimer greatly extended survival, and mice of this treatment group were free of leukemia. These findings suggest that this format for bispecific proteins allows for robust simultaneous engagement with both antigens of interest in a manner conducive to T cell cytotoxicity against AML. We believe this presents a compelling modular system for bispecific antibodies, where CD3- and CD33-binding domains can be readily swapped with domains binding to other cancer- or immune cell-specific antigens, and can be further developed into a trispecific system engaging other immune cells or extending half-life with anti-albumin or Fc domains.
405

Rôle des cellules dendritiques plasmocytoïdes dans la leucémie myélomonocytaire chronique / A Role for Plasmacytoid Dendritic Cells in Chronic Myelomonocytic Leukemia

Lucas, Nolwenn 02 November 2017 (has links)
Une infiltration médullaire par des cellules plasmocytoïdes CD123+ est présente chez certains patients atteints de leucémie myélomonocytaire chronique (LMMC), mais les mécanismes aboutissant à la génération de ces cellules, et leur impact sur l'évolution de la maladie n'ont jamais été explorés. En cytométrie en flux, nous avons détecté un excès de cellules mononucléées négatives pour les marqueurs de lignée lymphocytaires, monocytaires et granulocytaires, et exprimant CD123, HLA-DR, BDCA-2, BDCA-4 et CD4 dans la moelle de 39/161 patients(24%) . L'analyse de ces cellules en microscopie conventionnelle et électronique, en cytométrie en flux et leur analyse transcriptomique identifient ces cellules comme d'authentiques cellules dendritiques plasmocytoïdes (pDCs). Ces pDCs répondent à la stimulation par des agonistes de Toll-like receptor 9 (TLR9) et de TLR7 en produisant respectivement de faibles quantités d'interféron alpha et de grandes quantités d'interleukine 8. Le séquençage d'exome complet de monocytes et de pDCs triés détecte une ou plusieurs mutations qui activent constitutivement la voie Ras chez tous les patients riches en pDCs, avec un certain niveau d'hétérogénéité sous-clonale. Les cellules CD34+ de patients LMMC riches en pDCs génèrent de grandes quantités de pDCs en culture ex vivo, y compris en l'absence de FMS-like tyrosine kinase 3-ligand (Flt3-L). Dans des expériences de coculture, les pDCs extraites de moelles de LMMC riches en pDC diminuent la prolifération des cellules CD34+ de manière dose-dépendante. L'augmentation des pDCs est associée à une expansion des lymphocytes T régulateurs (Tregs). L'analyse rétrospective d'une cohorte de 212 patients atteints de LMMC a montré un effet mitigé de l'infiltration médullaire par des cellules CD123+ TCL1+ sur la survie, avec une tendance à une meilleure survie globale chez les patients riches en pDCs, mais également un risque accru de transformation en leucémie aigüe. / Bone marrow infiltration with plasmacytoid CD123high cells was identified in a fraction of patients with a chronic myelomonocytic leukemia (CMML), but the mechanisms promoting the generation of these cells and their impact on disease evolution remain poorly known. Using a multiparametric flow cytometry assay, we detect an excess of lineage-negative mononucleated cells expressing CD45, CD123, HLA-DR, BDCA-2, BDCA-4 and CD4 in the bone marrow of 39/161 (24%) CMML patients. Conventional and electron microscopy, flow cytometry and gene expression analyses identify these cells as authentic plasmacytoid dendritic cells (pDCs). These pDCs respond to Toll-like receptor-9 (TLR9) and TLR7 agonists by producing low levels of interferon alpha and high levels of interleukin-8 (IL-8), respectively. Whole exome sequencing of sorted monocytes and pDCs detects one or several mutations that constitutively activate the Ras pathway in every pDC-rich patient, with some subclonal heterogeneity. CD34+ cells from pDC-rich CMML produce high level of pDCs in ex vivo culture, even in the absence of FMS-like tyrosine kinase 3 ligand (FLT-3L). In co-culture experiments, pDCs collected from the bone marrow of pDC-rich CMML decrease the proliferation of CD34+ cells in a dose-dependent manner. pDC increase is associated with an expansion of CD4+ regulatory T cells (Tregs). Retrospective analysis of a cohort of 216 CMML patients detected a mitigated effect of bone marrow infiltration with CD123high, TLC1+ cells on disease outcome, including a trend for a better overall survival of patients with a pDC excess but also an increased risk of leukemic transformation.
406

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.
407

The protein tyrosine phosphate, SHP2, functions in multiple cellular compartments in FLT3-ITD+ Leukemia

Richine, Briana Marie 09 March 2016 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / FMS-like tyrosine receptor kinase-internal tandem duplications (FLT3-ITDs) are the most frequent deleterious mutations found in acute myeloid leukemia (AML) and portend a poor prognosis. Currently, AML patients typically achieve disease remission, yet undergo high rates of disease relapse, implying a residual post-treatment reservoir of resistant malignancy-initiating cells. This begs for new therapeutic approaches to be discovered, and suggests that targeting multiple cellular compartments is needed for improved therapeutic approaches. We have shown that the protein tyrosine phosphatase, Shp2, associates physically FLT3-ITD at tyrosine 599 (Y599) and positively regulates aberrant STAT5 activation and leukemogenesis. We also demonstrated that genetic disruption of Ptpn11, the gene encoding Shp2, increased malignancy specific survival of animals transplanted with FLT3-ITD-transduced cells, suggesting that Shp2 may regulate the function of the malignancy-initiating cell. Taken together, I hypothesized that inhibiting Shp2 can target both FLT3-ITD+ AML tumor cells as well as FLT3-ITD-expressing hematopoietic stem cells. To study this hypothesis, I employed two validation models including genetic inhibition of Shp2 interaction with FLT3-ITD in 32D cells or genetic disruption of Shp2 in FLT3-ITD-expressing HSCs. Using FLT3-ITD-expressing 32D cells as an AML tumor model, I found that mutating the Shp2 binding site on FLT3-ITD (Y599) reduced proliferation in vitro and increased latency to leukemia onset in vivo. Further, pharmacologic inhibition of Shp2 preferentially reduced proliferation of FLT3-ITD+ primary AML samples compared to FLT3-ITD- samples, and cooperated with inhibition of the lipid kinase, phospho-inositol-3-kinase (PI3K), and of the tyrosine kinase, Syk, to reduce proliferation of both FLT3-ITD+ and FLT3-ITD- AML samples. To evaluate the stem cell compartment, I crossed a murine locus-specific knock-in of FLT3-ITD with Shp2flox/flox; Mx1-Cre mice to generate FLT3-ITD; Shp2+/- mice and found that Shp2 heterozygosity dramatically inhibits hematopoietic stem cell engraftment in competitive transplant assays. Further, I found that lineage negative cells from FLT3-ITD; Shp2+/- mice demonstrated increased senescence compared to control mice, suggesting that Shp2 may regulate senescence in FLT3-ITD-expressing hematopoietic stem cells. Together, these findings indicate a cooperative relationship between the tyrosine phosphatase, Shp2, and the kinases PI3K and Syk in AML tumor cells, and indicate that Shp2 plays a positive role in the stem cell compartment to promote stem cell function of the malignancy-initiating cell in AML. Therefore, targeting Shp2 may hold therapeutic benefit for patients with FLT3-ITD+ AML.
408

Characterization of simian T-cell leukemia virus type 1 in naturally infected Japanese macaques as a model of HTLV-1 infection / HTLV-1感染モデルとしてのニホンザルに自然感染しているサルT細胞白血病ウイルス1型の解析

Miura, Michi 24 March 2014 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第18129号 / 医博第3849号 / 新制||医||1001(附属図書館) / 30987 / 京都大学大学院医学研究科医学専攻 / (主査)教授 小柳 義夫, 教授 髙折 晃史, 教授 五十嵐 樹彦 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
409

Global DNA methylation analysis of chronic lymphocytic leukemia and acute myeloid leukemia reveals distinct clinically relevant biological subtypes

Giacopelli, Brian John 06 November 2020 (has links)
No description available.
410

The Importance of Maintaining PU.1 Expression Levels During Hematopoiesis

Houston, Isaac Benjamin 08 October 2007 (has links)
No description available.

Page generated in 0.0452 seconds