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Biomedical subjects

P F Weinheimer

Publications and source records attributed to P F Weinheimer.

At least 19 recordsLinked to original sources

Tetrameric immune macroglobulins in three orders of bony fishes.

The immune IgM-like macroglobulins were isolated from three species of bony fishes (Ictalurus punctatus, Lepisosteus osseus, and Polyodon spathula) representing the three orders of the subclass Actinopterygii. These macroglobulins were found to have sedimentation coefficients of 14 S and molecular weights of 600,000-630,000. The carbohydrate compositions were determined and found to be different from that of human macroglobulins. After reduction and alkylation, the heavy and light chains could be separated by gel filtration and were found to have molecular weights of approximately 70,000 and 23,000 respectively. The amino acid compositions of these chains were similar to those of mammalian IgM heavy and light chains. The macroglobulins were found by electron microscopy to have a tetrameric structure, in contrast to the pentameric structure found in mammalian, chicken, and shark IgM, i.e. in species later on the evolutionary scale.

Amino Acids↗

Bactericidal antibody response in the Pacific hagfish, Eptatretus stoutii.

The hagfish, Eptatretus stoutii, has been shown to synthesize bactericidal antibodies after injections of gram-negative organisms. These bactericidins could be detected as early as 2 days after the primary injection. Secondary responses were accelerated, although titers were not significantly higher than those reached in the primary response. The bactericidins of hagfish were found to react with other gramnegative enteric bacteria, but not with gram-positive strains. The bactericidins show a lesser degree of specificity and a shorter induction period than other hagfish antibodies or most antibodies induced in higher vertebrates. The bactericidal activity was temperature dependent and could be irreversibly destroyed by heating at 50 C for 20 min. Immune sera were subjected to gel filtration on Sephadex G-200, and bactericidal activity was found to be associated with the excluded peak indicating a high-molecular-weight component. Evidence indicates that inducible immune responses of this bactericidal type represent a primitive capacity which arose before the emergence of vertebrate species.

Animals↗