Circulating immune complexes were detected in 62 individuals with malignant melanoma by precipitation with isolated human C1q and polyclonal rheumatoid factors. In 56 patients the C1q deviation assay ...showed low to moderate levels of complexes, with increased amounts with advancing stage of disease. Both heavy (greater than 19S) and intermediate (7S to 19S) varieties were present, and complexes containing tumor antigen-antibody or antibody-anti-antibody were identified. Complexes were found in the kidneys of one patient with malignancy and the nephrotic syndrome and in two further patients with melanoma in whom there were no clinical manifestations of nephrosis. Serial determinations in 51 patients showed slow cyclic variations in the levels of complexes and fluctuations in response to therapy. The coexistence of anti-antibodies, immune complex disease, and anergy in melanoma patients may indicate a deranged immune regulation consequent to chronic antigenic stimulation by the tumor.
Severe erosion occurs in the leading edge of the moving blades at the exhaust end of large steam turbines. It is customary to fit a shield of some hard material such as Stellite 6 to reduce the rate ...of damage. Metallographic examination of specimens tested on a simulative rig showed that the erosion damage occurring was similar to that found on shields removed from service. This rig was therefore used to study the early stages of erosion in a cobalt-based alloy (Stellite 6). Specialized optical and electron metallographic techniques were used to study the microstructural changes occurring. Considerable deformation was observed in the matrix at a very early stage, without metal removal. At this time fissuring could also be seen at some carbide/matrix interfaces. As testing continued small pits were seen to form, generally adjacent to carbides. The growth of these pits was then studied. From these observations the following four-stage mechanism is proposed for erosion in Stellite 6: (1) Matrix deformation by slip. (2) Cracking at carbide-matrix boundaries. (3) Propagation of these cracks under repeated loading. (4) Intersection of crack fronts allowing material removal.
The present report concerns the demonstration of the exclusive detection among peripheral blood T-lymphocytes of the S-100 protein within the CD8-positive subpopulation which lacks the antigen ...recognized by the 9.3 monoclonal antibody. Highly purified human peripheral blood T-cell subsets, obtained by means of panning techniques, were first stained, by an immunofluorescence method, with purified anti-S-100 protein antibodies. The vast majority of S-100 protein- (and, specifically, its beta subunit) positive cells were detected in the CD8-positive, 9.3-negative subset. This subset had previously been shown to comprise all the alloantigen-specific and histamine-inducible suppressor T-cells. Other T-subsets, even those showing either CD8-positivity (but 9.3-positivity) or 9.3-negativity (but CD8-negativity), were, as a rule, S-100 negative. Immunoelectronmicroscopy confirmed that the S-100-positive cells, showing peroxidase activity within the cytoplasm, were found exclusively within the CD8-positive, 9.3-negative subset. This finding of S-100 protein in cells of a specific T8 suppressor subset extends the range of the known distribution of this protein and may have important implications concerning its role in the modulation of immune responses.
