ABSTRACT
A model is developed for the dynamics of a territorial population for which mortality and the search for suitable territories are treated as continuous processes and birth occurs as a discrete pulse once each year. It is shown that the trajectories converge either to a fixed annual cycle or to extinction for both groups as long as the individual reproductive success and survival rate for the territorial population exceeds that for those individuals not holding territories. Conditions that determine whether the population will persist are provided.
Subject(s)
Birds , Models, Theoretical , Population Dynamics , Animals , Death , Mathematics , Survival Rate , Territoriality , Time FactorsABSTRACT
This report describes experience with a technique for the isolation of mononuclear cells from large quantities of human bone marrow using a blood cell processor. The procedure includes the separation of the bone marrow aspirates by concentrating and collecting interface buffy coat cells. A mononuclear white cell-enriched fraction is then obtained with ficoll-hypaque in the blood cell processor. Finally, the bone marrow white cells are washed to remove the ficoll-hypaque and the contaminating plasma. The entire procedure is carried out in a closed system. The automated method of isolating mononuclear cells proved superior to the manual method in both the recovery of cells and the time needed to process the marrow. Also, the risk of microbial contamination is substantially reduced. When marrow white cells processed by this method and cryopreserved were transfused subsequently into patients who had previously undergone high-dose chemotherapy and radiotherapy, engraftment, as indicated by a rise in the absolute granulocyte count of greater than 1000 per mm3, occurred within 20 days. This semiautomated technique provides a convenient, rapid, and reliable method for processing and preparing large numbers of viable marrow cells.
Subject(s)
Bone Marrow Transplantation , Cell Separation/instrumentation , Adolescent , Adult , Automation/instrumentation , Bone Marrow/drug effects , Bone Marrow/radiation effects , Cell Separation/methods , Diatrizoate , Diatrizoate Meglumine , Drug Combinations , Ficoll , Humans , Leukocyte Count/drug effects , Leukocyte Count/radiation effects , Leukocytes, Mononuclear/drug effects , Leukocytes, Mononuclear/radiation effects , Leukocytes, Mononuclear/transplantation , Middle Aged , Transplantation, Autologous/instrumentation , Transplantation, Autologous/methodsABSTRACT
A recent evaluation of the immediate-spin crossmatch has revealed limitations when used for the detection of ABO incompatibilities in tests between group B patient sera and group A2B donor red blood cells. Presented with the option of deleting the anti-globulin crossmatch, the study reported here was conducted to determine whether the anti-globulin crossmatch would detect the ABO incompatibilities missed by the immediate spin. Results of 1,000 crossmatches between group B patient sera and group A2B red blood cells showed that the anti-globulin phase was capable of detecting a higher percentage of incompatibilities than the immediate-spin procedure, 79.4-86.8% versus 40-64.4%, respectively, depending on the enhancement used. Although anti-globulin testing did detect a substantially higher number of incompatibilities, are the increased cost of reagents and technologists' time used in performing the anti-globulin crossmatch justified for the detection of ABO incompatibilities? Due to limitations observed with the anti-globulin test in addition to budgetary and fiscal constraints, retention of the anti-globulin testing purely for ABO compatibility is not warranted.
