Masakatsu Imamura

Immunohistologic detection of lymphocyte subpopulations infiltrating in human oral cancer with special reference to its clinical significance

Cancer tissues from 30 patients with squamous cell carcinoma of the oral cavity were examined immunohistopathologically as to the responsiveness of the host against its own cancer cells in both biopsy and surgically resected specimens from the same patients. Subpopulations of the infiltrating lymphocytes in cancer tissues were identified on paraffin‐embedded serial sections by a modified indirect immunoperoxidase technique (PAB method) in which it was combined with peroxidase‐antiperoxidase (PAP) complex and avidin‐biotin system with rabbit anti‐human B‐cell, peripheral T‐cell sera. Macrophages were also identified by nonspecific acid esterase staining. T‐cells were predominant over B‐cells in 26 of 30 tissues in biopsy specimens and 23 of 30 in surgically resected specimens with bleomycin treatment. T‐cell infiltration in the peripheral region of the tumor was more prominent than that in the stroma among the cancer nests. T‐cells surrounded the cancer nests, occasionally accumulated around the cancer cells, infiltrated at the marginal part of the cancer nests, and frequently produced perivascular massive accumulations. B‐cells and macrophages, on the other hand, were almost absent or negligible around cancer tissues. The grade of T‐cell infiltration, especially in biopsied specimens, was correlated well to the size of the tumor, and also more marked significantly in patients without cervical lymph node metastasis than in those with lymph node metastasis. Furthermore, there was a significant correlation between the grade of T‐cell infiltration at the peripheral region of the invading cancer mass in initial biopsy specimens and the clinical tumor regression rates with bleomycin treatment, but it did not correlate to the surgically resected specimens. These facts suggest that T‐cells might inhibit the development and spreading of the cancer cells, and that the T‐cell infiltration correlates with the clinical course or prognosis of the oral cancer patients.

Acinic cell carcinoma of minor salivary gland origin

We describe a case of acinic cell carcinoma of the right soft palate in a 65-year-old man. The primary symptom was a painless swelling of the palate, which was partially ulcerated with a granulomatous appearance. Ultrastructurally, the tumor cells were mainly composed of differentiated acinuslike cells containing numerous round secretory granules identical to those in normal serous salivary glands. The tumor cells frequently contained numerous long crystalloid structures in the cytoplasm. Furthermore, tumor cells demonstrating degrees of squamous differentiation were present. These cells contained intracytoplasmic keratin filaments and a few keratohyaline granules. They formed a glandular acinar space in direct contact with the typical acinic cells with secretory granules. These observations suggest that acinic tumor cells have a degree of multipotentiality.

Frequency and antigenicity of type C retrovirus-like particles in human placentas

Seventeen placentas from normal Japanese women, obtained from 15 full term gestations and at 2 earlier gestational periods, were observed by electron microscopy for the presence of type C retrovirus-like particles. Immature free and budding particles were found in 16 placentas including those obtained pre-term. Free virus-like particles were seen in the intercellular spaces and within the lysosomes of syncytiotrophoblasts of the chorionic villi. Forms budding from syncytiotrophoblasts were found in 3 cases. Coincident data with the electron microscopic observations were obtained by immunohistological methods. Specific positive staining with antisera against heterogeneic whole murine leukaemia virus were seen within the cytoplasm of trophoblastic cells both in and along the basal lamina.

Preparation of Cell Lysate for Separation of Polyoma DNA from Cellular DNA by Sedimentation Velocity

Velocity. Tohoku J. exp. Med., 1973, 111 (4), 347-351 A simple procedure was devised to prepare the cell lysate for clear separation of viral and cellular DNA by sedimentation velocity allowing simultaneous observation of changes of both DNAs. This method was also useful to detect grades of fragmentation of DNA due to treatment of cells with drugs or to physical influences. •\•\ polyoma virus; DNA; sedimentation velocity centrifugation