Atresia (z1591)

ATRESIA (from the Greek a - negative particle, and trepsis - nutrition), a term denoting severe nutritional disturbance, used mainly to denote the severe form of atrophy [Parrot's atresia] of infants on artificial feeding (see Infantile atrophy). In addition, the term A. has also been applied in pathology for one category of cases, namely, to explain the fact of the impossibility of transferring malignant tumors from one species of animal to another. From mouse to mouse, for example, a cancerous tumor can be transplanted; but in transplantations from mouse to rat, the cancer cells live and can even proliferate only for a short time after transplantation, after which they dissolve; whereas in transplantation from the first rat to a second, while the tumor cells transplanted to the first rat from the mouse still retain their viability, the cells transferred from it to the second rat immediately begin to degenerate and die. Ehrlich gave the following explanation for this phenomenon: in the mouse organism there are nutritional substances needed for the growth of mouse tumors; but the rat does not have these substances (A. for cancer cells, atreptic immunity); in the organism of the first rat, the transplanted cells still live for some time, because along with them a small amount of nutritional material is transferred from mouse to rat; but in the second rat there is no longer any such material. However, this interpretation met with objections.