BACKGROUND Blood cell formation is maintained by the replication of hematopoietic stem cells (HSC) that continuously feed downstream "compartments" where amplification and differentiation of cells occurs, giving rise to all blood lineages. Whereas HSC replicate slowly, committed cells replicate faster as they become more differentiated. METHODOLOGY/SIGNIFICANT FINDING We propose a multi-compa...

Because of the retinoic acid receptor(RAR ) gene’s involvement in acute promyelocytic leukemia, the important role of RARs in hematopoiesis is now well established. However, relatively few studies of hematopoiesis have focused on the role of the retinoid X receptors (RXRs), the obligate heterodimeric partners of the RARs. We sought to establish whether conditional targeting of RXR in early hema...

Recent advances in our understanding of the molecular basis of inherited neutrophil disorders and complementary studies in transgenic mouse models have provided new insights into the normal mechanisms regulating myelopoiesis and the functional responses of mature neutrophils. Neutrophil specific granule deficiency is a rare disorder of neutrophil function characterized by a lack of neutrophil s...

The hallmark of stem and progenitor cell activity in the adult is reconstitution of cells, tissues, and organs under stress conditions such as disease and injury. The immense regenerative capacity of the immunohematopoietic system is best emphasized by spontaneous recovery after radiochemotherapy and therapeutic transplantation of reconstituting progenitors in oncology patients, with perspectiv...

BACKGROUND Adenosine triphosphate (ATP)-dependent chromatin remodeling SWI/SNF-like BAF and PBAF complexes have been implicated in the regulation of stem cell function and cancers. Several subunits of BAF or PBAF, including BRG1, BAF53a, BAF45a, BAF180, and BAF250a, are known to be involved in hematopoiesis. Baf200, a subunit of PBAF complex, plays a pivotal role in heart morphogenesis and coro...

Extramedullary hematopoiesis is characterized by the presence of hematopoietic tissue outside the bone marrow. Extrathoracic extramedullary hematopoiesis is a rare and usually asymptomatic condition. We report a case of a 38-year-old female with paraspinal and presacral extramedullary hematopoiesis with polycythemia vera. Clinical and laboratory evaluation, along with radiological and histopath...

Hematological disorders, especially single lineage abnormalities, have been described in hyperthyroidism. Pancytopenia has been reported, without myelodysplastic syndrome or megaloblastic anemia. We studied the peripheral blood smear and the bone marrow aspiration and biopsy of a 65-year-old lady, who presented with pancytopenia and thyrotoxicosis due to multinodular goiter. She denied ingestin...

HSCs maintain the circulating blood cell population. Defects in the orderly pattern of hematopoietic cell division and differentiation can lead to leukemia, myeloproliferative disorders, or marrow failure; however, the factors that control this pattern are incompletely understood. Geminin is an unstable regulatory protein that regulates the extent of DNA replication and is thought to coordinate...

RUNX1 encodes a DNA-binding α subunit of the core-binding factor, a heterodimeric transcription factor. RUNX1 is a master regulatory gene in hematopoiesis and its disruption is one of the most common aberrations in acute leukemia. Inactivating or dominant-negative mutations in the RUNX1 gene have been also identified in pedigrees of familial platelet disorders with a variable propensity to deve...

The goal of the present study was to evaluate the activation patterns of p38 mitogen-activated protein kinase (MAPK) in myeloproliferative disorders (MPDs) and myelodysplastic syndromes (MDSs). Phosphorylated (activated) p38 MAPK was analyzed immunohistochemically in formalin-fixed decalcified bone marrow core biopsy specimens from 32 MPD, 33 MDS, and 11 control cases. Moderate p38 activation w...