Search results for "Haematopoiesi"
showing 10 items of 183 documents
Unusual B cell morphology in inflammatory bowel disease.
2012
B lymphocytes express various different types of surface immunoglobulins that are largely unrelated to other hematological lines, although some reports have described a relationship between malignant B cells and other cells such as macrophages. Multiple genes of hematopoietic lineage, including transcription factors, are co-expressed in hematopoietic stem cells and progenitors, a phenomenon referred to as "lineage priming". Changes in the expression levels and timing of transcription factors can induce the lineage conversion of committed cells, which indicates that the regulation of transcription factors might be particularly critical for maintaining hierarchical hematopoietic development. …
Analysis of human dysplastic haematopoiesis in long-term bone marrow culture
1989
In this paper we have analysed the behaviour of myelodysplastic marrow in a long-term bone marrow liquid culture system (LTBMC) from eleven patients with myelodysplastic syndromes with regard to cellularity, day-7 and day-14 CFU-GM growth, cluster formation, adherent cells and CFU-F formation. An altered CFU-GM pattern was found in 64% of cases at diagnosis, while normal growth was seen in the remaining cases, all of which were affected by refractory anaemia. The levels of CFU-GM, as well as cellularity, were reduced in myelodysplastic marrows compared to normal controls over the whole duration of LTBMCs. Cases with a normal CFU-GM level at diagnosis also showed pathological behaviour when …
Erythrophagocytic tumour cells in melanoma and squamous cell carcinoma of the skin
1997
Aims: Erythrophagocytosis is a characteristic feature of tumour cells in malignant histiocytosis, some leukaemias, lymphomas, and also reactive histiocytes in the haemophagocytic syndrome associated with a variety of infections and neoplasms. It has also been found exceptionally in metastatic malignant epithelial cells in bone marrow and lymph nodes. We present two cases, a cutaneous malignant melanoma and an acantholytic squamous cell carcinoma, in which erythrophagocytosis by tumour cells was demonstrable by both light and electron microscopy. Methods and results: The melanocytic and squamous nature of these cells was supported by the immunohistochemical detection of HMB45, S100, and NKI-…
Human Epidermal Langerhans Cells Replenish Skin Xenografts and Are Depleted by Alloreactive T Cells In Vivo
2011
Abstract Epidermal Langerhans cells (LC) are potent APCs surveying the skin. They are crucial regulators of T cell activation in the context of inflammatory skin disease and graft-versus-host disease (GVHD). In contrast to other dendritic cell subtypes, murine LC are able to reconstitute after local depletion without the need of peripheral blood-derived precursors. In this study, we introduce an experimental model of human skin grafted to NOD-SCID IL2Rγnull mice. In this model, we demonstrate that xenografting leads to the transient loss of LC from the human skin grafts. Despite the lack of a human hematopoietic system, human LC repopulated the xenografts 6 to 9 wk after transplantation. By…
Growth hormone and hematopoiesis: A retrospective analysis on a large cohort of children with growth hormone deficiency
2018
Objective: Few large-scale studies regarding the impact of GH deficiency (GHD) on hematopoiesis in children have been reported. Our aim was to investigate hematopoiesis indices in a large cohort of GHD children at diagnosis and during GH treatment (GHT) and any correlation with hormonal parameters. Design: Clinical and biochemical data of children with idiopathic GHD at diagnosis and annually up to 36 months of GHT were retrospectively evaluated. Overall, 255 children reached 12 months, 140 children 24 months and 86 children 36 months of follow-up during GHT. Results: At baseline, 18.4% of GHD children and 10.1% of controls showed normocytic anemia. GHD children showed lower hemoglobin (Hb)…
Interleukin (IL)-22 receptor 1 is over-expressed in primary Sjogren's syndrome and Sjögren-associated non-Hodgkin lymphomas and is regulated by IL-18.
2015
Summary The aim of this study was to elucidate more clearly the role of interleukin (IL)-18 in modulating the IL-22 pathway in primary Sjögren's syndrome (pSS) patients and in pSS-associated lymphomas. Minor salivary glands (MSGs) from patients with pSS and non-specific chronic sialoadenitis (nSCS), parotid glands biopsies from non-Hodgkin lymphomas (NHL) developed in pSS patients, were evaluated for IL-18, IL-22, IL-22 receptor 1 (IL-22R1), IL-22 binding protein (IL-22BP) and signal transducer and activator of transcription-3 (STAT-3) expression. MSGs IL-22R1-expressing cells were characterized by confocal microscopy and flow cytometry in pSS, nSCS and healthy controls. The effect of recom…
Bone marrow failure by cytomegalovirus is associated with an in vivo deficiency in the expression of essential stromal hemopoietin genes.
1997
Bone marrow (BM) failure associated with cytomegalovirus (CMV) infection is a feared complication after clinical BM transplantation. Experiments in long-term BM cultures have indicated that BM stromal cells (BMSC) are targets of productive CMV infection, but an in situ infection of BM stroma remained to be documented, and the pathomechanism is open to question. Here we describe a murine in vivo model of lethal CMV aplastic anemia (CMV-AA). The reconstitution of hematopoietic progenitor cells expressing stem cell factor (SCF) receptor was found to be defective in CMV-AA. While murine CMV replication in permissive parenchymal tissues is cytolytic, the hematopoietic cord was found to be a site…
Hematopoietic stem cell function in b-thalassemia is impaired and is rescued by targeting the bone marrow niche
2020
Abstract Hematopoietic stem cells (HSCs) are regulated by signals from the bone marrow (BM) niche that tune hematopoiesis at steady state and in hematologic disorders. To understand HSC-niche interactions in altered nonmalignant homeostasis, we selected β-thalassemia, a hemoglobin disorder, as a paradigm. In this severe congenital anemia, alterations secondary to the primary hemoglobin defect have a potential impact on HSC-niche cross talk. We report that HSCs in thalassemic mice (th3) have an impaired function, caused by the interaction with an altered BM niche. The HSC self-renewal defect is rescued after cell transplantation into a normal microenvironment, thus proving the active role of…
MicroRNAs, the immune system and rheumatic disease.
2008
MicroRNAs (miRNAs) have been implicated in the pathogenesis of rheumatic disease and are, therefore, a potential target for drug development. This Review describes the well-established roles of miRNAs in hematopoiesis and the immune response, the molecular action of miRNAs in the simultaneous post-transcriptional regulation of multiple targets, and the evidence for roles of specific miRNAs in rheumatic disease. MicroRNAs (miRNAs) are short noncoding RNA molecules that modulate the expression of multiple target genes at the post-transcriptional level and are implicated in a wide array of cellular and developmental processes. In hematopoietic cells, miRNA levels are dynamically regulated duri…
Tumor Control in a Model of Bone Marrow Transplantation and Acute Liver-Infiltrating B-Cell Lymphoma: an Unpredicted Novel Function of Cytomegalovirus
2002
ABSTRACTTumor relapse and cytomegalovirus (CMV) infection are major concerns in the therapy of hematopoietic malignancies by bone marrow transplantation (BMT). Little attention so far has been given to a possible pathogenetic interplay between CMV and lymphomas. CMV inhibits stem cell engraftment and hematopoietic reconstitution. Thus, by causing maintenance of bone marrow aplasia and immunodeficiency, CMV could promote tumor relapse. Alternatively, CMV could aid tumor remission. One might think of cytopathogenic infection of tumor cells, induction of apoptosis or inhibitory cytokines, interference with tumor cell extravasation or tumor vascularization, or bystander stimulation of an antitu…