No evidence for active viral infection in unicentric and idiopathic multicentric Castleman disease by Viral-Track analysis.

Castleman disease (CD) is a rare hematologic disorder characterized by pathologic lymph node changes and a range of symptoms due to excessive cytokine production. While uncontrolled infection with human herpesvirus-8 (HHV-8) is responsible for the cytokine storm in a portion of multicentric CD (HHV-8-associated MCD) cases, the etiology of unicentric CD (UCD) and HHV-8-negative/idiopathic MCD (iMCD) is unknown. Several hypotheses have been proposed regarding the pathogenesis of UCD and iMCD, including occult infection given the precedent established by HHV-8 infection.

Immune-mediated thrombocytopenia and IL-6-mediated thrombocytosis observed in idiopathic multicentric Castleman disease.

Idiopathic multicentric Castleman disease (iMCD) is a rare haematological disorder characterized by generalized lymphadenopathy with atypical histopathological features and systemic inflammation caused by a cytokine storm involving interleukin-6 (IL-6). Three clinical subtypes are recognized: thrombocytopenia, anasarca, fever, renal dysfunction, organomegaly (iMCD-TAFRO); idiopathic plasmacytic lymphadenopathy (iMCD-IPL), involving thrombocytosis and hypergammaglobulinaemia; and iMCD-not otherwise specified (iMCD-NOS), which includes patients who do not meet criteria for the other subtypes. Disease pathogenesis is poorly understood, with potential involvement of infectious, clonal and/or autoimmune mechanisms.

MyD88-dependent TLR signaling oppositely regulates hematopoietic progenitor and stem cell formation in the embryo.

Hemogenic endothelial (HE) cells in the dorsal aorta undergo an endothelial-to-hematopoietic transition (EHT) to form multipotent progenitors, lympho-myeloid biased progenitors (LMPs), pre-hematopoietic stem cells (pre-HSCs) and adult-repopulating HSCs. These briefly accumulate in intra-arterial hematopoietic clusters (IAHCs) before being released into the circulation. It is generally assumed that the number of IAHC cells correlates with the number of HSCs.

Identification of a Multipotent Progenitor Population in the Spleen That Is Regulated by NR4A1.

The developmental fate of hematopoietic stem and progenitor cells is influenced by their physiological context. Although most hematopoietic stem and progenitor cells are found in the bone marrow of the adult, some are found in other tissues, including the spleen. The extent to which the fate of stem cells is determined by the tissue in which they reside is not clear.

Prolonged drug selection of breast cancer cells and enrichment of cancer stem cell characteristics.

Background: Cancer stem cells are presumed to have virtually unlimited proliferative and self-renewal abilities and to be highly resistant to chemotherapy, a feature that is associated with overexpression of ATP-binding cassette transporters. We investigated whether prolonged continuous selection of cells for drug resistance enriches cultures for cancer stem-like cells.

Methods: Cancer stem cells were defined as CD44+/CD24⁻ cells that could self-renew (ie, generate cells with the tumorigenic CD44+/CD24⁻ phenotype), differentiate, invade, and form tumors in vivo.