[Electron microscopic observations on Bacteroides thetaiotaomicron].

Three strains of B. thetaiotaomicron have been isolated from caeca of BALB/c-nu/+ mice of SPF. These Bacteroides are obligately anaerobic, Gram-negative, non-spore-forming and non-motil without flagella rods. A characteristic of staining is deep at ends and stainless at the medium of a rod. The isolation and identification of these strains has been reported in 1987. This paper introduced only the results of EM observations. Under the SEM, the unstained area of rods is always showing a concavity, which is just a nucleoid in sections under the TEM. Many lamellar corpuscles have been found in cell plasma. Some of them have been secreted out of the cells. The chemical properties and physiological functions of them are unknown.

[Erythrophagocytic cancer cells].

The phagocytosis of senescent red cells by the monocyte-macrophage system and neutrophils is a normal physiological phenomenon. However, the erythrophagocytosis by malignant tumor cells was also reported, such as plasma cells of multiple myeloma, acute lymphoblastic leukemia cells and oat cells of bronchogenic carcinoma, etc. This paper describes the erythrophagocytosis by signet-ring cells of adenocarcinoma of the lung observed by electronmicroscope in 1982 and supported by light microscopy and cytochemical tests.