Correlation of CD34+ cell counts with volume of bone marrow collected for allogeneic bone marrow harvests.

The quantity of bone marrow collected for allogeneic bone marrow transplantation is based on collecting 10 to 15 cc of bone marrow/kg of recipient weight. We hypothesized that the percentage of CD34+ cells collected during a bone marrow harvest decreased at the end of the harvest because of increasing amounts of peripheral blood contamination. We performed a prospective, blinded study in which we measured CD34+ percentages and cell counts at 200-cc intervals during bone marrow harvests from 11 consecutive human leukocyte antigen (HLA)-matched sibling bone marrow donors. We observed that the percentage of CD34+ cells in aspirated bone marrow did not vary significantly from the start to the end of the bone marrow harvest, and the total number of CD34+ cells/kg increased in a linear fashion, thus disproving our original hypothesis. In conclusion, the percentage of CD34+ cells in aspirated bone marrow will remain constant throughout a bone marrow harvest.

Ursodiol prophylaxis against hepatic complications of allogeneic bone marrow transplantation. A randomized, double-blind, placebo-controlled trial.

BACKGROUND: Hepatic complications are a major cause of illness and death after bone marrow transplantation. OBJECTIVE: To confirm the results of a pilot study that indicated that ursodiol prophylaxis could reduce the incidence of veno-occlusive disease of the liver. DESIGN: Randomized, double-blind, placebo-controlled study. SETTING: Tertiary care teaching hospital. PATIENTS: 67 consecutive patients undergoing transplantation with allogeneic bone marrow (donated by a relative) in whom busulfan plus cyclophosphamide was used as the preparative regimen and cyclosporine plus methotrexate was used to prevent graft-versus-host disease. INTERVENTION: Before the preparative regimen was started, patients were randomly assigned to receive ursodiol, 300 mg twice daily (or 300 mg in the morning and 600 mg in the evening if body weight was > 90 kg), or placebo. MEASUREMENTS: Patients were prospectively evaluated for the clinical diagnosis of veno-occlusive disease, the occurrence of acute graft-versus-host disease, and survival. RESULTS: The incidence of veno-occlusive disease was 40% (13 of 32 patients) in placebo recipients and 15% (5 of 34 patients) in ursodiol recipients (P = 0.03). Assignment to placebo was the only pretransplantation characteristic that predicted the development of veno-occlusive disease. The most significant predictor of 100-day mortality was the diagnosis of veno-occlusive disease. The difference in actuarial risk for hematologic relapse in patients with chronic myelogenous leukemia and nonhepatic toxicities between the two groups was not statistically significant (13% in the ursodiol group and 20% in the placebo group; P > 0.2). CONCLUSION: Ursodiol prophylaxis seemed to decrease the incidence of hepatic complications after allogeneic bone marrow transplantation in patients who received a preparative regimen with busulfan plus cyclophosphamide.

Serologic evidence of Yersinia pestis infection in small mammals and bears from a temperate rainforest of north coastal California.

From 1983 to 1985, 463 serum samples from 11 species of mammals in Redwood National Park (RNP) (California, USA) were evaluated for antibodies to Yersinia pestis by the passive hemagglutination method. Yersinia pestis antibodies occurred in serum samples from 25 (36%) of 69 black bears (Ursus americanus), one (50%) of two raccoons (Procyon lotor), five (3%) of 170 dusky-footed woodrats (Neotoma fuscipes), and one (less than 1%) of 118 deer mice (Peromyscus maniculatus). Two hundred seventy-three flea pools, consisting of 14 species of fleas, were collected from small mammals and woodrat nest cups. Viable Y. pestis were not isolated from any of the flea pools. Significant between-year variations in the frequencies of seropositive bear or small mammal sera were not observed. A significantly higher frequency of plague antibodies was observed in bear sera taken during September collections. Frequencies of seropositive bear sera did not vary significantly by sex or age group of bears. Significant differences were not observed in the frequencies of seropositive small mammals by forest habitat type in which they were captured. This is the first report of Y. pestis infection in Redwood National Park, and the first detailed report of Y. pestis activity in a temperate rainforest.