Search results for "Leukemia"
showing 10 items of 976 documents
Autocrine transforming growth factor- from chronic lymphocytic leukemia-β cells interferes with proliferative T cell signals
1999
Chronic lymphocytic leukemia (CLL) is characterized by the accumulation of noncycling B cells in lymphatic and extralymphatic tissues. In the present study we investigated the possible contribution of TGF-beta, as secreted by CLL-B cells, on this low proliferative state. CLL-B cells were shown to express TGF-beta RNA and to release bioactive TGF-beta into culture supernatants. Antibody neutralization of endogenously secreted TGF-beta increased the proliferation of CLL-B cells as cultured in the presence of IL-2 or IL-4 or in direct contact with activated CD4+ T cells. In these culture systems, addition of exogenous TGF-beta downregulated basal and cytokineinduced proliferation of CLL-B cell…
Nanoparticles and antigen-specific T-cell therapeutics: A comprehensive study on uptake and release
2015
Aim: T lymphocytes are used as cellular therapeutics in many disease entities including cancer. We investigated the uptake and retention of nanoparticles (NPs) by these nonphagocytic cells. Materials & methods: Uptake, release and toxicity of various polymeric NP preparations were analyzed by flow cytometry, confocal laser scanning microscopy and transmission electron microscopy. T-cell effector functions were measured using IFN-γ-ELISPOT and 51Chromium-release assays. Results: Amino-functionalized NPs were efficiently ingested by antigen-specific T cells without adversely influencing effector functions. NPs were stored in membrane-surrounded vesicles, with major proportions released e…
Microenvironment Regulation of IL23R/IL-23 Axis Drives Chronic Lymphocytic Leukemia (CLL) Progression
2015
Abstract Background : CLL displays a considerable degree of clinical heterogeneity, which is in part ascribable to clone-intrinsic biological features and that are also influenced by clone-extrinsic events related to the microenvironment. Among the dynamics-taking place within the CLL microenvironment, those finalized to the induction of an overly inflammatory milieu may significantly impact on the CLL natural history by hijacking the immunological microenvironment at the same time fostering clone fitness. IL-23 acts as a prototypical pro-inflammatory mediator representing a promising therapeutic target. We analyzed the ability of CLL cells to sense IL-23 through the IL-23R complex (consist…
Reconstitution of CD52-Negative CD4 T Cells after Alemtuzumab-Based T Cell Depleted Allogeneic Hematopoietic Stem Cell Transplantation
2008
Abstract The human CD52 molecule is the target of the monoclonal antibody Alemtuzumab, which is used for treating patients with chemo-refractory chronic lymphocytic leukemia as well as for T cell depletion (TCD) in the context of allogeneic hematopoietic stem cell transplantation (HSCT). The molecule is expressed on the surface of lymphocytes, dendritic cells and to a lesser extent on blood-derived monocytes. Previously, investigators have demonstrated that the surface expression of CD52 on T cells is down-regulated after in vitro incubation with Alemtuzumab. By treating purified human CD4 T cells over 4 hours with 10 μg/mL Alemtuzumab in medium supplemented with 10% human AB serum in vitro…
Post-chemotherapy physical fitness level on children with diagnosis of leukemia: results of a pilot study
2012
Introduction: Children with diagnosis of leukemia are at risk for developing neuromuscular and musculoskeletal complications such as decreased muscle strength, impaired gross and fine motor performance, decreased energy expenditure, osteonecrosis, and osteoporosis. These secondary complications due to the medical interventions may lead to activity limitations and participation restrictions in daily life experiences. However, few Authors suggest that if children participate in an individualized physical therapy exercise program, these limitations may be prevented or at least reduced. We evaluated the level of physical fitness on children with diagnosis of leukemia (C-LK) during the post-chem…
EPI-CT: design, challenges and epidemiological methods of an international study on cancer risk after paediatric and young adult CT
2015
Computed tomography (CT) has great clinical utility and its usage has increased dramatically over the years. Concerns have been raised, however, about health impacts of ionising radiation exposure from CTs, particularly in children, who have a higher risk for some radiation induced diseases. Direct estimation of the health impact of these exposures is needed, but the conduct of epidemiological studies of paediatric CT populations poses a number of challenges which, if not addressed, could invalidate the results. The aim of the present paper is to review the main challenges of a study on the health impact of paediatric CTs and how the protocol of the European collaborative study EPI-CT, coor…
Procalcitonin levels in plasma in oncohaematologic patients with and without bacterial infections.
2004
Abstract Background: The flogosis markers currently in use show both low sensitivity and specificity, particularly in neoplastic and degenerative diseases. Procalcitonin (PCT) is a pro-peptide of calcitonin produced mainly but not only in the C-cells of the thyroid glands and, as several studies show, PCT levels in plasma increase during infections. Bacterial infections are also the main cause of death in oncological patients. Furthermore, in patients with leukaemia in chemotherapy recovery, infections often induce relapses. The aim of the present study is to detect PCT levels in plasma in oncohaematologic patients with and without infections. Methods: The study was carried out on 54 patien…
Flow cytometry diagnosis in myelodysplastic syndrome: Current practice in Latin America and comparison with other regions of the world
2019
Background: Flow cytometry (FC) is a valuable tool for the diagnosis of myelodysplastic syndromes (MDS). We present results of a survey carried out to evaluate FC current practice for MDS diagnosis in Latin America (LA), focusing on markers used and characteristics of the clinical diagnostic report. Compliance to IMDSflow recommendations was also evaluated. These practices were then compared with those used in other countries. Methods: An online survey was sent through the Grupo Latino-Americano de Mielodisplasia to LA cytometrists and other international scientific societies. Results: 91 responses from 15 LA countries were received. The median of the number of markers used was 20 +/- 4.5, …
MEF2C and SOCS2 in stemness regulation
2015
The physiologic stemness of hematopoietic stem cells (HSC) relies on mechanisms constitutively active under steady state and is fundamental to maintain a lifelong HSC reservoir. On the other side, similar stemness features sustained by partially overlapping molecular circuits, which have recently come into focus, confer aggressive aggressiveness in leukemia clones. Suppressor of Cytokine Signalling 2 (SOCS2) belongs to the SOCS family, comprising eight members (SOCS1–7 and CIS) with similar structures, which are induced upon JAK/STAT activation and function as negative regulators. Recent evidences have demonstrated that SOCS2 is endowed with immunological functions in differentiated cells b…
Laurus nobilis L. Seed Extract Reveals Collateral Sensitivity in Multidrug-Resistant P-Glycoprotein-Expressing Tumor Cells.
2015
The frequent failure of standard cancer chemotherapy requires the development of novel drugs capable of killing otherwise drug-resistant tumors. Here, we have investigated a chloroform extract of Laurus nobilis seeds. Fatty acids and 23 constituents of the volatile fraction were identified by gas chromotography/flame ionization detection (GC/FID) and gas chromatography/mass spectrometry (GC/MS), in good agreement with (1)H NMR (nuclear magnetic resonance) spectrum. Multidrug-resistant P-glycoprotein-expressing CEM/ADR5000 leukemia cells were hypersensitive (collaterally sensitive) toward this extract compared to drug-sensitive CCRF-CEM cells, whereas CEM/ADR5000 cells were 2586-fold resista…