Subject(s)
Cognition , Linguistics , Humans , Models, Psychological , Reaction Time , Reading , SemanticsABSTRACT
A patient with aplastic anemia received an ABO incompatible bone marrow transplant (BMT) from an HLA identical sibling. Weekly HLA antibody screens were performed as part of the BMT protocol. At the time of transplant, a hemolytic anti-Le(a) was detected in the Le (a-b-) donor. The Le (a-b+) recipient had no red cell or LCT antibody. A hemolytic anti-Le(a) was detected in the recipient on day 8, but no LCT reactivity was noted at this time. On day 15, the LCT panel demonstrated reactivity with 9 of 50 panel cells without apparent HLA specificity. Graft vs. host disease (GVHD) was present on the skin at this time. The dose of cyclosporin A was increased, but by day 20 the GVHD worsened and the LCT titers increased to 8. This strong reactivity was noted only in the Le (a+) panel members (12/50) and was neutralized with commercial Lewis substance. On day 34 there was no evidence of GVHD, but the lymphocytotoxic anti-Lea continued to be present. The patient began experiencing renal and gastrointestinal difficulties by day 48, and expired on day 60. In renal transplants the kidneys retain their Lewis type and secrete Lewis substance in the urine. In our experience BMT patients retain their Lewis type regardless of the type of the donor. The Lewis system has been linked to renal allograft rejection, and Lewis antigens may function as transplantation antigens in BMT patients as well. In addition, lymphocytotoxic Lewis antibodies can mask other significant HLA antibodies and must be identified when screening patients in need of plateletpheresis products.
Subject(s)
Antibodies/immunology , Bone Marrow Transplantation , Lewis Blood Group Antigens/immunology , Anemia, Aplastic/blood , Anemia, Aplastic/complications , Anemia, Aplastic/immunology , Anemia, Aplastic/therapy , Bone Marrow/immunology , Cytotoxicity, Immunologic , Graft vs Host Disease/complications , Graft vs Host Disease/mortality , HLA Antigens/analysis , HLA Antigens/immunology , Humans , Male , Tissue DonorsABSTRACT
The occurrence of relatively long notes, and the repetition of melodic phrases are important cues to the metre, or regular beat, of a piece of music. A model of how people use this information to infer the metre of unaccompanied melodies is described here. The model is in the form of a computer program, and involves a definition of melodic repetition which encompasses repetitions that include certain kinds of variation. The program has been applied to the task of analysing the metric structure of the forty-eight fugue subjects of the Well-Tempered Clavier by J S Bach. The program is discussed in relation to other models both of musical understanding and of sequential concept learning.
