Effect of excess parathyroid hormone on human bone marrow fibroblasts.

Patients with uremia have excess levels of parathyroid hormone (PTH). It has been reported that excess PTH is associated with bone marrow fibrosis. The present study was undertaken to examine the in vitro effect of intact 1-34 PTH and the active 1-34 N-terminal fragment on human bone-marrow-derived fibroblasts.

Fatal aplastic anemia in a child with Down's syndrome.

An infant with Down's syndrome developed severe persistent neutropenia at the age of 9 months and fluctuating anemia and thrombocytopenia at one year of age which terminated as full-blown aplastic anemia at 26 months of age. Immunological evaluation revealed increased peripheral and bone marrow lymphocytes and impaired blood OKT4: OKT8 ratio. Bone marrow granulocyte-macrophage colony forming cells (GM-CFC) were markedly increased, while peripheral blood mononuclear cells (PBMN) produced normal numbers of colonies.

Human bone marrow fibroblast proliferation and GM-CFC colony formation in patients with acute leukemia.

The proliferation of bone marrow (BM)-derived fibroblasts and granulocyte-macrophage progenitors (GM-CFC) was studied in culture in 23 patients with acute leukemia (AL). The number of GM-CFC colonies was significantly lower in patients with infiltrated BM when compared to those in remission: 17 +/- 12 vs. 125 +/- 35 colonies per 2 X 10(5) cells (p less than 0.