Relationship between red blood cell transfusion requirements and severity of renal disease during the acute stage of hemolytic uremic syndrome.

Background: We performed a retrospective evaluation of patients with diarrhea-associated hemolytic uremic syndrome (D + HUS) with the aims of: (1) determining the rate of red blood cell (RBC) transfusions; (2) establishing the relationship between need for RBC transfusion and severity of renal involvement; (3) determining whether precise measurements of lactic dehydrogenase (LDH) levels can predict the rate of hemolysis and severity of renal disease.

Methods: A total of 288 patients with D + HUS were retrospectively divided into three groups based on dialysis treatment: group 1, no dialysis treatment (144 patients); group 2, dialysis for 1-10 days (67 patients); group 3, dialysis for ≥11 days (77 patients).

Results: Of the patients in groups 1, 2 and 3, 73.

Suppression of in vitro maintenance of non-promyelocytic myeloid leukemia clonogenic cells by all-trans retinoic acid: modulating effects of dihydroxylated vitamin D3, alpha interferon and 'stem cell factor'.

In a liquid culture system, all-trans retinoic acid (ATRA), alone and in combination with dihydroxylated vitamin D3 (D3) or alpha interferon (alphaIFN) at concentrations achievable in vivo, could significantly suppress the maintenance of non-promyelocytic myeloid leukemia clonogenic cells (CFU-L) in 9/20, 9/18 and 7/11 cases, respectively. That suppression was counteracted only slightly by the addition of 'stem cell factor', a cytokine which promotes CFU-L expansion in vitro. Differentiated cells slightly increased in 5/17 cases only, suggesting the prevalence of anti-proliferative rather than differentiating mechanisms.

Stem cell factor improvement of proliferation and maintenance of hemopoietic progenitors in myelodysplastic syndromes.

Human recombinant stem cell factor (rSCF) was tested for its capability of improving the defective growth of hemopoietic progenitors in 28 cases of myelodysplastic syndromes (MDS). In vitro growth and response to rSCF were quite variable. However, in most cases, rSCF stimulated CFU-GM growth induced by rG-CSF, rGM-CSF, rIL-3, 5637 conditioned medium (50-1400% enhancement).

Human recombinant stem cell factor stimulates in vitro proliferation of acute myeloid leukemia cells and expands the clonogenic cell pool.

Stem cell factor (SCF) is a new growth factor acting on early hematopoietic progenitor and stem cells. In our experiments human recombinant SCF stimulated short-term proliferation of accessory cell-depleted acute myeloid leukemia (AML) cells in 13/14 cases, as determined by 3H-thymidine (3H-TdR) incorporation and cell counts. Stimulatory activity was significantly greater than in the presence of GM-CSF and was comparable to that of granulocyte colony-stimulating factor (G-CSF), interleukin 3 (IL-3), and 5637 cell line supernatant (SN).