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To study the characteristics of the microenvironment of human bone marrow, fibroblasts derived from normal and aplastic anemia bone marrow aspirates or core biopsies were grown in culture. Normal bone marrow fibroblasts had a slow logarithmic phase of growth (8 days) with doubling times of 2 to 3 days. Aplastic anemia bone marrow fibroblasts had a rapid logarithmic phase of growth (5 to 6 days) and doubling times of 1 day. Dexamethasone (1 X 10(-8) M) stimulated the growth of normal fibroblasts. Growth of fibroblasts derived from aplastic anemia marrows was, however, inhibited by dexamethasone. Specific binding sites for the hormone were present in the normal fibroblasts (Bmax: 460-770 fmole/mg protein) whereas in the aplastic anemia fibroblasts the amount was very low (Bmax 27-215 fmole/mg protein). These observations suggest that in aplastic anemia, the bone marrow fibroblast, a cell constituent of the marrow microenvironment, has the capacity to develop and grow in vitro. However, this cell is different from normal bone marrow fibroblasts in its growth characteristics and response to dexamethasone.

A method is described for the separation of early and intermediate myeloid cells from human bone marrow aspirates. This easily performed procedure is based on preferential binding of lymphoid and late myeloid cells to DEAE-Cellulose-Sephadex G-25 columns.

Human bone marrow fibroblasts (BMF) were grown in vitro from normal (N) subjects and patients with aplastic anemia (AA). Growth studies in vitro revealed that both the N-BMF and AA-BMF had a logarithmic growth phase of eight days. Population doubling time for six of the 12 N-BMF and seven of the 12 AA-BMF was greater than 50 h. Five of the 12 AA-BMF studied in contrast to only two of the 12 N-BMF had a population doubling time of less than 50 h. The remaining four N-BMF had a population doubling time of greater than 100 h. During a similar duration in the logarithmic phase of growth, the AA-BMF underwent an average of 2.499 population doublings in comparison to 1.586 doublings by N-BMF (P = less than 0.01). The AA-BMF grew in multiple layers compared with the N-BMF, which usually grew as a monolayer. At the end of the logarithmic phase of growth, the AA-BMF also had a significantly higher number of cells per dish than the N-BMF (P = 0.02 on analysis of variance and covariance). These data suggest that a subgroup of AA-BMF grows faster than N-BMF and that the AA-BMF lack cell-to-cell inhibition. Testosterone, 3 alpha-etiocholanolone, and dexamethasone at 1 X 10(-8)M concentration, a physiological concentration, stimulated the growth of N-BMF as evidenced by increase in cell numbers and radioactive thymidine (3H-TdR) uptake. While dexamethasone had a stimulating effect on growth of N-BMF, it suppressed the growth of AA-BMF. Specific binding of radioactive dexamethasone (3H-dexa) was determined both for the N-BMF and AA-BMF. Specific binding sites for dexamethasone (Bmax) present on the N-BMF ranged from 460 to 770 fmol/mg protein). Bmax for AA-BMF was low (27-215 fmol/mg protein). In addition, the dissociation constant (Kd) was ten times lower for AA-BMF (1.0 X 10(-7) M) than for N-BMF (1.1 X 10(-8) M). The observations on the growth studies, the paradoxical response to dexamethasone, and the difference in the number of binding sites for dexamethasone indicate that the marrow fibroblasts from patients with aplastic anemia are abnormal.

The bleeding complications of some forms of thrombocytopenia are difficult to control. Many patients become refractory to platelet transfusions even when HLA-matched. We have successfully used aminocaproic acid to control bleeding in 13 patients with amegakaryocytic thrombocytopenia. Four patients receiving long-term therapy with this drug had striking reductions in the number of platelet transfusions required for capillary bleeding. No adverse effects have been noted save for orthostatic hypotension, which is ameliorated by a reduction in dosage. Quantitative platelet function changes have been impossible to demonstrate, but no changes were noted in four patients with normal platelet counts who were receiving high-dose aminocaproic acid for treatment of subarachnoid hemorrhage. Aminocaproic acid has proved to be a valuable agent in the management of patients with amegakaryocytic thrombocytopenia, especially in decreasing the need for platelet transfusions.

Twenty-nine patients with aplastic anemia and 11 patients with myelofibrosis were evaluated with indium-111 chloride bone-marrow imaging, ferrokinetics, and bone-marrow core biopsies. There was good correlation between the erythrocyte cellularity of the marrow and the In-111 bone-marrow scan grades in most patients. In some, the overall scan grade tended to underestimate the erythroid elements because the core biopsy had been taken from the area of the greatest radionuclide concentration on the scan. In patients with aplastic anemia, there was good correlation between the plasma iron clearance t1/2 and the scan grade. Less agreement was found in the comparison between the Fe-59 sacral and organ counts and the red-cell iron utilization. In patients with myelofibrosis, there was poor correlation between the surface counts over the sacrum and the red-cell iron utilization. Plasma iron clearances were abnormally short and were unrelated to the transferrin saturation levels. Eighteen patients were studied several times to evaluate their responses to steroid therapy. In all, there was good correlation between the bone-marrow imaging, the erythrocyte cellularity, ferrokinetics, and the patient's response to therapy. Indium-111 bone-marrow imaging is useful both in evaluating marrow erythroid activity and in following the response to therapy in patients with these diseases.

In 2 patients with the malignant carcinoid syndrome, a Swam-Ganz balloon tip, flow-directed catheter was used to occlude hepatic arterial flow and perfuse hepatic metastases with 5-fluorouracil. The first patient, symptomatic for 16 months, was rendered asymptomatic for 14 months after treatment. The second patient was relieved of severe diarrhea and generalized urticaria, but progression of the cardiac manifestations were unaffected. Symptoms of the carcinoid syndrome are usually the most debilitating aspect of this illness. When more conservative measures cannot alleviate their symptoms, hepatic artery occlusion with chemotherapeutic perfusion of metastases should be considered.

A cell fraction enriched in immature granulocytes was obtained after fractionation of human bone marrow by a three-step procedure. This fraction sediments at an average density of 1.073 and has a high content of myelocytes and metamyelocytes. It showed the highest specific uptake of etiocholanolone when compared to other bone marrow cell fractions. Autoradiographic studies demonstrated a higher number of silver grains over myelocytes and metamyelocytes than in other cell types. These results suggest the presence in human bone marrow of a target cell for etiocholanolone, located in the late mitotic or postmitotic pool or granulocytes.

A comparison has been made between the separation of nucleated cells from human bone marrow aspirates by high mol. wt polymers and the buffy coat techniques.

A patient with sickle cell anemia was hospitalized because of an acute erythropoietic aplastic crisis. 111In chloride bone marrow scintigraphy performed during the aplastic crisis showed markedly impaired uptake of the radionuclide and simultaneous 59Fe clearance T 1/2 studies were prolonged (420.9 min). Following recovery from the aplastic crisis 111In scintigraphy revealed an expanded marrow and the radioiron clearance T 1/2 was accelerated (20.9 min). The clinical course, hemograms and bone marrow aspirations correlated with marrow scintigraphy. 111In appears to be a valuable marrow scanning agent for assessing the presence of intramedullary erythropoietic activity.

A 28 year old white man with hemophilia A had, for several years, been successfully maintained on a home care program utilizing self-administration of factor VIII concentrates, but one such infusion resulted in severe anaphylaxis. An immunoglobulin E (IgE)-mediated hypersensitivity response was demonstrated by (1) the release of histamine from the patient's basophils in vitro upon challenge with several different lots of factor VIII concentrate; (2) immediate cutaneous response to commercial factor VIII, factor IX and cryoprecipitate; and (3) measurement of IgE antibodies against a commercial factor VIII preparation. A subsequent life-threatening hemorrhage required cautious infusion of another commercial lot of factor VIII concentrate. Despite pretreatment with antiallergic drugs and attempted desensitization, a moderately severe anaphylactic reaction was observed.