Specific alterations in the microvascular and connective tissue compartments of the hemopoietic microenvironment have been examined during erythropoietic regeneration and suppression in the murine spleen and bone marrow using in vivo microscopic and histochemical methods. The results have confirmed the concept of specific hemopoietic microenvironments and have demonstrated specific alterations ...

To define the basis for faulty granulopoiesis in patients with severe congenital neutropenia (SCN), the expression of granulocyte colony-stimulating factor receptor (G-CSFR) in primitive myeloid progenitor cells and their responsiveness to hematopoietic factors were studied. Flow cytometric analysis of bone marrow cells based on the expression of CD34, Kit receptor, and G-CSFR demonstrated a re...

In order to evaluate the role of the stromal bone marrow microenvironment in regulating granulopoiesis, we have examined the capacity of adult human proximal hemopoietic (PH) and distal nonhemopoietic (DNH) long bone to produce colony-stimulating activity (CSA), characterized the cellular sources of CSA, and quantitated the colony-forming cells (CFU-GM) of marrow from these sites. Stromal eleme...

There is evidence that neutrophil production is a balance between the proliferative action of granulocyte-colony-stimulating factor (G-CSF) and a negative feedback from mature neutrophils (the chalone). Two neutrophil serine proteases have been implicated in granulopoietic regulation: pro-proteinase 3 inhibits granulocyte macrophage-colony-forming unit (CFU-GM) growth, and elastase mutations ca...

The effect of biosynthetic recombinant insulin-like growth factor I/somatomedin C (IGF-I/Sm-C) and human growth hormone (hGH) on the in vitro growth and maturation of human marrow myeloid progenitors was investigated. Myeloid colony formation was maximally enhanced by 60 ng/ml IGF-I/Sm-C and by 250 ng/ml hGH, resulting in an increase in colony numbers of 41 +/- 7 and 38 +/- 4%, respectively (P ...

Significant elevation in the peripheral granulocyte count (more than 20,000) and the absence of overt infection are commonly associated with a wide variety of human neoplasms. Robinson demonstrated a dose correlation between the amount of the serum and urine levels of granulocyte-macrophage colony stimulating factor (GM-CSF) and the peripheral neutrophil counts. In vivo assessment of hematopoie...

Emergency granulopoiesis occurs in response to severe microbial infection. However, whether and how other blood components, particularly monocytes/macrophages and their progenitors, including hematopoietic stem/progenitor cells (HSPCs), participate in the process and the underlying molecular mechanisms remain unknown. In this study, we challenged zebrafish larvae via direct injection of Escheri...

Two patients with agranulocytosis associated with diphenylhydantoin (DPH) therapy and clinical data suggesting suppression of granulopoiesis were investigated using in vitro culture techniques for committed granulocyte I macrophage precursors. Addition of DPH to cultures containing the patients’ sara resulted in significant suppression of colony growth. Extensive studies on the acute serum from...

The immune response to Staphylococcus aureus infection in skin involves the recruitment of polymorphonuclear neutrophils (PMNs) from the bone marrow via the circulation and local granulopoiesis from hematopoietic stem and progenitor cells (HSPCs) that also traffic to infected skin wounds. We focus on regulation of PMN number and function and the role of pore-forming α-toxin (AT), a virulence fa...

To define the basis for faulty granulopoiesis in patients with severe congenital neutropenia (SCN), the expression of granulocyte colony-stimulating factor receptor (G-CSFR) in primitive myeloid progenitor cells and their responsiveness to hematopoietic factors were studied. Flow cytometric analysis of bone marrow cells based on the expression of CD34, Kit receptor, and G-CSFR demonstrated a re...