Local regulation of hematopoietic differentiation in the marrow requires close interactions with components of the microenvironment. In this study, we explored the capacity of human marrow hematopoietic progenitor cells to adhere in vitro to the extracellular matrix (ECM) secreted by human marrow fibroblasts. When marrow mononuclear cells were incubated on ECM-coated dishes, all types of progen...

Endotoxin was detected in all erythropoietin preparations tested and was removed from four lots, without loss of erythropoietic activity, by adsorption with limulus amebocyte lysate. Comparison of adsorbed (endotoxin-depleted) and nonadsorbed (endotoxin-containing) erythropoietin preparations demonstrated significant inhibition of CFU-e and BFU-e in vitro by nonadsorbed erythropoietin at concen...

Human gamma interferon (HuIFN gamma) was evaluated for its effects on the release from human peripheral blood T lymphocytes (greater than 98% pure) stimulated by phytohemagglutinin (PHA) of activities that can stimulate granulocyte-macrophage (CFU-GM) colonies and clusters, erythroid (BFU-E) bursts, and mixed (CFU-GEMM) colonies. T lymphocytes did not release these activities in the absence of ...

Twelve cases of transient erythroblastopenia of childhood (TEC) have been studied to evaluate their marrow cell erythropoiesis in vitro and the effect on it of their serum or IgG. The number of colony-forming units-erythroid (CFU-E) and burst-forming units-erythroid (BFU-E) in the bone marrow of nine cases was extremely variable and did not allow any conclusion regarding the pathogenesis of thi...

An association has been established between human la-like antigenic determinants. expression during DNA synthesis on multipotential (CFU-GEMM) and erythroid (BFU-E) progenitor cells. and the regulatory action of acidic isoferritins in vitro. Treatment of human bone marrow cells with monoclonal anti-la (NE1 -01 1 ) plus complement inhibited colony formation of CFU-GEMM and BFU-E by 50%-70%. Redu...

The effects of recombinant human macrophage colony-stimulating factor (rhCSF-1) in long-term marrow cultures (LTMC) established from normal bone marrow cells were examined. When added during the first 3 weeks of culture (every second day, at 15 ng/mL), rhCSF-1 strongly inhibited the growth of all hematopoietic progenitors analyzed (colony-forming unit-MIX [CFU-MIX], CFU-granulocyte macrophage [...

A collaborative evaluation of the MS-2 urine screening system indicated that the automated method could successfully identify at least 84% of urine specimens that contained greater than or equal to 10(5) colony-forming units per ml. Most specimens not detected as positive by the system contained primarily diphtheroids and yeasts. Excluding those specimens which contained diphtheroids and yeasts...

Vertical wind shear and concentration gradients of viable, airborne bacteria were used to calculate the upward flux of viable cells above bare soil and canopies of several crops. Concentrations at soil or canopy height varied from 46 colony-forming units per m over young corn and wet soil to 663 colony-forming units per m over dry soil and 6,500 colony-forming units per m over a closed wheat ca...

Charcoal-yeast extract agar is a new bacteriological medium that supports excellent growth of the Legionella pneumophila. It results from modifications made in an existing L. pneumophila medium, F-G agar. Yeast extract, instead of an acid hydrolysate of casein, serves as the protein source. Beef extractives and starch are not added. Activated charcoal (Norit A or Norit SG) is included at 0.20% ...

The interaction of Cryptococcus neoformans with the murine macrophage-like cell line J774.16 was studied in the presence and absence of monoclonal antibodies (MAbs) to the capsular polysaccharide glucuronoxylomannan (GXM). In the absence of MAb 2H1 to GXM, coincubation of J774.16 cells with C. neoformans reduced fungal colony-forming units in only 26.6% of 21 independent experiments. In the pre...