Biomedical subjects
Publications and source records attributed to R J Sassetti.
A patient with IgE myeloma, presenting with bone lesions and modest anemia without plasma cell leukemia or hepatosplenomegaly, is described. The findings are compared with those of other patients with this and the more common forms of multiple myeloma.
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Optimal regionalization of a blood banking system requires a hierarchical structure based on an analysis of preexisting elements in the region to determine at what level of activity economics of scale, cost effectiveness and efficiency will be greatest. We have applied operations research techniques to segments of the blood service complex. This paper is an overview of the general results of this research. From analysis of the data in each segment, a mathematical response function is developed for such managerial processes as demand forecasting, requirements computation, crossmatch and recycle control at each level of the hierarchy in a regional system. These processes in independent hospital blood banks are contrasted with those in hospital blood banks and transfusion services which are dependent on central blood banks for their supply. An example is presented of a model which is useful in the planning of a regional system. Implementation of these hierarchical models in hospital blood banks can reduce outdating, size of inventories and shortage. In central blood banks, these models can minimize shipment quantities, determine optimal transshipments and the most efficient routing.
In granulocyte donors during centrifugation leukapheresis (CL), total hemolytic complement, Clq, C3, factor B, and properdin decreased, but only to the extent expected from hemodilution. Crossed immunoelectrophoresis showed no C3 conversion in plasma obtained from the leukapheresis appeared during CL or in donor plasma immediately after CL. When serum was incubated with hydroxyethyl starch, total hemolytic complement did not decrease and C3 conversion was not detected by crossed immunoelectrophoresis. This investigation revealed no evidence that complement activation is associated with CL.
The use of citrate-phosphate-dextrose-adenine as an anticoagulant for whole blood increases the storage period permitted for whole blood and red cells from 21 to 35 days. A simulation model was used to analyze the possible consequences for outdates and shortages of the addition of adenine. The model accepts as input (1) the maximum age (21 or 35 days), (2) parameters describing the demand and supply distributions, and (3) parameters describing inventory control (crossmatch recycle period, transfusion fraction, deviation from optimal target inventory levels). These parameters were varied over wide ranges, and a full factorial design was carried out. The observed shortage and outdate rates were then related (via multiple regression) to the parameter values. The resulting shortage and outdate functions indicated the effect of parameter changes, including extending the lifetime from 21 to 35 days, and the joint effect of changing more than one parameter. Conclusions indicate that, while the contribution of an increased lifetime to reducing shortages and outdates can be substantial, this contribution can be easily dissipated by relaxing the tightness of other inventory management controls.
Because of their structural similarity to dialysis membranes, six plasma separator membranes were evaluated for the ability to activate complement, as judged by immunoconversion of the third component of complement in crossed immunoelectrophoresis. A polysulfone and two cellulose acetate membranes were relatively strong alternative pathway activators. Polypropylene, poly[vinylidine fluoride] and polyvinyl-chloride derivative membranes were weak activators in some sera. Membrane activation was inhibited in citrate-anticoagulated but not in heparin-anticoagulated plasma. The results of such in vitro screening should be of value in selecting materials and anticoagulation regimens for membrane plasma separators.
Plasma exchange donation accomplishes the selective donation of cryoprecipitate. It facilitates the repeated donation of large quantities of factor VIII by individual donors and reduces donor exposure for recipients. A highly motivated donor is described who has undergone 103 donations between May 1983 and March 1987, producing 359,460 IU of factor VIII and supplying all the factor VIII needed since August 1983 by his severely affected hemophiliac son, now age 14. The donor has remained in good health, and no significant abnormalities have been noted in hematologic, biochemical, immunologic, coagulation, and serum protein testing. Extensive experience with this donor suggests that repeated plasma-exchange donation is safe and can sometimes allow single-donor support of severe hemophiliacs.
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