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Transplantation of normal bone marrow to mice with the Chediak-Higashi syndrome (CHS) resulted in normal granulopoiesis and a reversal of their increased susceptibility to challenge with intravenous Candida albicans. These findings suggest that (1) the leukocyte defect in CHS can be reversed by marrow transplantation and (2) the mechanism for increased susceptibility to infection in these animals is due to a bone- marrow-derived cellular defect. Because of similarities between murine and human CHS, bone marrow transplantation might be considered as a mode of therapy in selected cases of the human disease.

Pseudomonas aeruginosa pneumonia was produced in dogs with radiation- induced leukopenia to study the comparative efficacy of several different therapies. In a randomized control trial, five treatment regimens were compared: no antibiotics or granulocytes (controls), gentamicin (5 mg/kg/day), carbenicillin (500 mg/kg/day), gentamicin and carbenicillin (same dosages), and daily granulocyte transfusion (minimum 5 x 10(9) cells/day) plus gentamicin (5 mg/kg/day). The most effective therapy was gentamicin plus granulocyte transfusions. Gentamicin alone was not significantly better than no specific therapy. Carbenicillin with or without gentamicin gave intermediate results. This study further supports the utility of granulocyte replacement therapy of infections in severely granulocytopenic subjects. The results also indicate that the relative value of granulocyte transfusions depends upon the specific antibiotic regimen with which these transfusions are compared.

This study investigated the anemia of dietary magnesium deficiency in inbred Fisher white rats using freeze-fracture electron microscopy. The plasma membranes of erythrocytes from animals receiving two different magnesium-deficient and control diets were observed at weekly or biweekly intervals for 6 wk. The earliest changes were small plaques on the external surface (ES) and fracture face (PF) of erythrocyte plasma membranes, which occurred after 2 wk of either magnesium-deficient diet. These plaques persisted and increased in size with progressive magnesium deficiency. When fully developed, the plaques consisted of round or oval elevations approximately 30–50 nm in diameter outlined by a narrow raised border. The surface of the plaques was smooth and devoid of intramembranous particles. Incubation of erythrocytes from magnesium-deficient rats in a physiologic solution containing 2 meq/liter magnesium for 1 hr at 37degrees C did not alter the appearance of the plaques. Erythrocytes from control rats, obtained during the same time periods, showed no plaques. Thus, a deficiency of magnesium in rats altered erythrocyte membrane structure.

Previous reports have shown that endotoxin decreases serum iron in experimental animals. In this study fever was produced in nine female and nine male normal subjects in order to define the temporal and quantitative changes in serum iron and ferritin concentrations. Six volunteers were randomly given bacterial endotoxin (5 ng/kg) or saline intravenously and received the alternative compound a week later. Serial blood samples were drawn at 4-hr intervals for a 24-hr period, beginning when the compound was administered, for the determination of serum iron and ferritin concentrations. The same study was performed with intramuscular etiocholanolone (0.3 mg/kg) or the vehicle, propylene glycol, as a control, but the first blood sample was obtained 9 hr after the compound was given. In addition, blood samples were obtained at 12-hr intervals in six volunteers for 11 days after an intramuscular injection of etiocholanolone. The results showed a significant increase (p less than 0.005 for etiocholanolone, P less than 0.01 for endotoxin) in serum ferritin and a significant decrease (p less than 0.005 for etiocholanolone, p less than 0.001 for endotoxin) in serum iron for both pyrogenic compounds compared with the control compounds. However, the amount of fever and the changes in the iron parameters were greater with etiocholanolone. One episode of induced fever with etiocholanolone effected changes in serum ferritin and iron concentrations that lasted 10 days. Thus this study demonstrated that a single episode of fever in man produced rapid and prolonged changes in serum iron and ferritin concentrations.