吉田肉腫に対する発育抑制実驗

1. For the cultivation of Yoshida sarcoma the medium of chicken plasma and chick embryo juice with the addition of rat ascites is most suitable. Addition of a piece of chick embryo heart is also excellent.<br>2. Other than rat ascites, spleen extracts from normal rats act as growth promoter. Spleen extracts from tumor bearing rats are less effective. Extracts prepared from brain, testis, liver, etc., do not permit the growth of the sarcoma.<br>3. Tumor reimplanted into the peritoneal cavity, after the removal of the tumor previously successfully implanted in the same rats subcutaneously, resulted in negative, demonstrating the development of immunity. The re-implanted sarcoma cells in these experiments survived generally 2 or 3 days but never more than 6 days in the peritoneal cavity.<br>4. Injections of tris-β-chloroethylamine into 7 cases resulted in the disappearance of sarcoma cells within 2 days after the first injection. However, due to the strong secondary action no marked prolongation of life was obtained. The suitable doses of nitrogen mustard may be 0.1mg or less per 100g body weight.<br>5. In 10 cases treated with placenta preparation there was 1 in which the tumor regressed, and in 1 other there was the prolongation of life to 60 days.<br>6. Estrin was injected subcutaneously into 7 cases in which sarcoma was successfully implanted into testis. Tumor disappeared in 2 of these cases.<br>7. The tumor was not influenced by mixed typhoid-paratyphoid vaccine, benzene, etc. Placenta preparation and estrin certainly produced regression of tumors in some cases, but the results were not constant.<br>8. The regressive changes found in sarcoma cells intraperitonelly injected into animals which were previously successfuly implanted subcutaneously and from which the resulting tumor removed, were identical with those frequently met with in the terminal stage of the usual positive transplantation in normal rats, and there was nothing characteristic about the sarcoma cell changes in immunized animals.<br>9. In the case of retransplantation in the peritoneal cavity, after the removal of previously implanted subcutaneous sarcoma, granulocytic reaction disappeared in 1 or 2 days, followed by the rapid reciprocal increase of mononuclear cells, in which stage vacuolization of mononuclear cells, appearance of phagocytic cells and desquamation of the lining cells of peritoneum were conspicuous.<br>10. Sarcoma cells show neutral red rosettes, surrounded by rod-shaped Janus green stained bodies. In some cells the Janus green stained bodies alone, without the neutral red rosette, are seen probably representing younger forms.<br>11. The Janus green and neutral red stained bodies and granules appear most markedly during 2-3 days after transplantation, and they tend to be less numerous during the middle to terminal stages.<br>12. Cells not showing stained granules with Janus green-neutral red double supravital technique, if transplanted to a new host, will suddenly show these stained structures, which may be regarded to have some relation to the changes in cellular function or in growth environments.<br>13. Granules in the sarcoma cells in fixed specimens stained with acid fuchsin or iron hematoxylin are of rod or granular form, scattered in the cytoplasm. Nucleoli are large, of complex form, and occur in irregular numbers.<br>14. When sarcoma cells do not show stained granules with Janusg reenneutral red double staining, the addition of certain solutions, such as physiological saline, Ringer's, CaCl₂, MgSO₄ or KCl in certin concentration, vitamin B₁, glucose, saliva, chicken serum, etc., induces the appearance of Janus green stained granules.