[The effects of preventive regimens for the prophylaxis of infection after bone marrow transplantation].

The effects of regimens on the prevention of infection in 42 adult leukemia patients receiving bone marrow transplantation was analyzed. Standard risk patients (transplantation in 1st remission of acute leukemia and chronic phase of chronic myelogeneous leukemia received marrow from HLA compatible sibling or autologous marrow) showed shorter febrile days than high risk patients (transplantation in more advanced stage of leukemia and transplantation from unrelated donor), 1.33 mean days vs. 4.93 mean days respectively. Poorer intake of non-absorved antibiotics resulted in higher rate of bacterial colonization in stool after transplantation. And that, the degree of gut sterilization correlated with the duration of febrile days during the period of less than 100/microliter peripheral neutrophil count in high risk patients. Thus, prophylactic regimens of infection in bone marrow transplantation should be considered according to the risk of patient, that is, more practical and complete prophylaxis in risk patients and more conventional one in standard risk patients.

Alteration of bone status with ascorbic acid deficiency in ODS (osteogenic disorder Shionogi) rats.

Rats with hereditary defects in ascorbic acid (AsA) synthesis (ODS rats) subjected to AsA-deficiency for 3 weeks showed reductions of plasma alkaline phosphatase and dry and ash weights of the tibia, but no body weight alteration. In accordance with the chemical changes, bone loss and decrease of bone formation by AsA deficiency but not by malnutrition were observed in contact microradiographs of the tibia and by a tetracycline double labeling technique, respectively. The mechanical properties of femora measured by a three point-bending procedure were also altered by AsA deficiency for 3 weeks and showed decreases of 59% in toughness, 32% in strength, 32% in ductility and 22% in stiffness. The biomechanical changes by AsA deficiency were greater than the chemical changes in bone, indicating the usefulness of measuring mechanical properties as a sensitive method for the evaluation of the bone status. The second moment of the area of the femur was not changed by AsA deficiency. These results suggest that AsA deficiency in ODS rats causes marked bone loss and reduction in bone formation, which is accompanied by a greater reduction in biomechanics of the femur without causing macroarchitectural changes.