Natural suppressor (NS) cells, which exert nonspecific suppressive activity in an unprimed manner, have been found in mouse, rabbit and monkey bone marrow (BM). In the present study, we characterize ...NS cells in human BM. NS activity was found in a fraction of low density (1.055-1.065 g/ml) BM cells that had been depleted of T cells, B cells, and monocytes. The NS activity was significantly decreased by the depletion of CD34+ or CD33+ cells but not CD56+ cells. The NS activity was indeed detected in isolated CD34+ cells and further enriched in CD34+CD33+ cells. Hematopoietic progenitor cells committed to the myeloid lineage were also enriched in the CD34+CD33+ cells, which significantly correlated to the NS activity. From these findings, it is strongly suggested that NS activity in human BM is exerted by the myeloid hematopoietic progenitors. Since cell-to-cell contact was not necessary for the action, NS cells seemed to secrete soluble mediator(s). Transforming growth factor-beta 1 and leukemia inhibitory factor were, however, not the candidates, based on experiments using neutralizing antibodies.
We have developed and launched on the market a high-quality color picture tube called SUPERBRIGHTRON_. which is equipped with two types of color filters (both filtering layers internal and exteral) ...for the first time in the world. The internal filter consists of blue, green and red filters formed between the corresponding color-emitting phosphors and the face glass, which the external filter is a selective-absorption filter formed on the outside of the face glass. These filters achieve remarkable improvements in contrast and color gamut by absorbing a large amount of the ambient light with little reduction in brightness, and by selectively absorbing the sub-band portions of the light emitted by the phosphors. Improvements in contrast of 36% and 74% and in color gamut of 7% and 12%. against external filter tube and without any filtering layers tube, have been obtained with this picture tube.
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