Koh Masuda

Differences in the ability of cells to fuse are mediated by strains of epstein-barr virus

Epstein‐Barr virus (EBV) preparations from both NPC‐KT cells (NPC‐EBV) and P3HR‐1 cells (HR‐l‐EBV) can induce cell fusion between EBV receptor (EBVR)‐positive Raji cells and EBVR‐negative cells, but other strains of EBV cannot induce cell fusion. The effect of these two EBV isolates on ability of cells to fuse has been studied to determine if there are differences in the biological properties of the different EBV isolates, particularly the isolates obtained from nasopharyngeal carcinoma such as NPC‐EBV. The frequency of cell fusion between NPC‐EBV‐superinfected Raji cells and EBVR‐negative epithelial cells (Ad‐AH) was increased more than 30‐fold in the presence of medium containing 1% dimethylsulfoxide (DMSO). However, the frequency of cell fusion between HR‐1‐EBV‐superin‐fected Raji cells and Ad‐AH cells was unaffected under the same conditions. The data show that differences in the ability of cells to fuse ore induced by variants of EBV in response to DMSO. These differences may be important in elucidating the different biological properties of EBV isolates and might have implications for the pathophysiology of EBV‐associated illness.

CHONDROMA OF THE NASAL CAVITY AND NASOPHARYNX -A CASE OF CHONDROMA ARISING FROM THE NASAL SEPTUM-

Chondromas of the nasal septum are rare. A case of chondroma originating in the left side of the nasal septum is reported. The patient, a 61-year-old female, presented bilateral nasal obstruction, headache, and nasal bleeding. The tumor was removed surgically through the transpalatal approach under general anesthesia. No recurrence was noticed after 6 months follow-up.

Cervical ranula arising from a projection of the sublingual gland through the mylohyoid muscle

A case of cervical ranula is presented, which originated from a projection of the sublingual gland into the suprahyoid region. A diagnosis of cervical ranula could not be established preoperatively because there was no intraoral involvement of the ranula. A cervical approach was used, and the correct diagnosis was made during the operation.

Spontaneous Lymphoblastoid Transformation of Cells Obtained from Human Tonsils

Spontaneous lymphoblastoid transformation of cells obtained from 25 human tonsils were investigated. Three Epstein-Barr virus (EBV) genome-positive lymphoblastoid cell lines were spontaneously established in tissue cultures in vitro from human tonsils. In addition, the frequency of spontaneous lymphoblastoid transformation was increased by the treatment of tumor promoter, 12-0-tetradecanoylphorbol-13-acetate and 18 lymphoblastoid cell lines were established. The data suggest that the human tonsil is a reservoir for EBV.

Development of Significant Sternoclavicular Joint Hypertrophy following Radical Neck Dissection

Radical neck dissection (RND) has proved to be effective in the en bloc removal of metastatic lymph nodes in the neck. This paper describes a case with severe sternoclavicular joint hypertrophy following RND. This condition should be differentiated both clinically and radiologically from metastases of the head of the clavicle. Computed tomography was found to be of value in the diagnosis of the condition.

Malignant Fibrous Histiocytoma Arising from the Vocal Cord

A rare case of malignant fibrous histiocytoma of the left vocal cord occurring in an 80-year-old man is described, with a review of the literature. There has been no recurrence for 24 months since the initial endolaryngeal microsurgery.

Further studies on growth characteristics of epstein-barr virus (EBV) genome-positive and -negative epithelial hybrid cell lines

Differences in tumorigenicity between the Epstein‐Barr virus (EBV) genome‐negative and ‐positive epithelial A2L/AH hybrid cell lines have been described recently. Further differences in growth characteristics of the two epithelial hybrid cells have since been examined. Differences were found in doubling time and cloning efficiency in agarose of the two cell lines. In addition, the EBV genome‐negative epithelial hybrid cell line (cl‐654), unlike the EBV genome‐positive epithelial hybrid cell line (cl‐1), failed to grow in the unmanipulated nude mice, but was successfully transplanted in 60Co‐irradiated nude mice. The histopathologic findings of tumors induced by the inoculation of cl‐654 cells in nude mice showed more differentiated carcinoma than the findings of tumors induced by cl‐1 cells.

Antinuclear antibodies in the sera of patients with nasopharyngeal carcinoma

We studied the production of heterophile antinuclear antibodies (ANAs) in the sera of 50 patients, 20 with nasopharyngeal carcinoma (NPC) and 30 with other head and neck cancers (laryngeal cancer and maxillary cancer), before and after radiation therapy. A higher incidence of ANAs was found in the sera of patients with NPC and ANA production in these patients was higher after radiation therapy. We therefore performed in vitro experiments to explore the mechanisms of ANA production in the serum of postirradiated NPC patients. X-ray-irradiated NPC-derived cells (NPC-KT) produced a large amount of Epstein-Barr virus (NPC EBV) compared with non-irradiated NPC-KT cells. Nasopharyngeal carcinoma EBV-infected lymphocytes produced high levels of ANAs. These data suggest that lymphocytes infected by EBV from NPC cells may produce ANAs in the sera of NPC patients.

Characteristics of Epstein-Barr Virus-Carrying Lymphoblastoid Cells Derived from Human Tonsil: EBV Production and Autoantibody Response

Tonsillar and peripheral blood lymphocytes from 20 patients with tonsillitis were examined for production of Epstein-Barr virus (EBV) and antinuclear antibodies within 2 weeks after EBV transformation. All established lymphoblastoid cell lines (LCLs) contained more than 90% EBV nuclear antigen-positive cells. However, no LCLs produced biologically active virus. On the other hand, 10 (50%) out of 20 tonsillar LCLs and 4 (20%) out of 20 peripheral blood LCLs produced autoantibodies. These results showed that there are differences in an EBV-induced lymphocyte autoantibody response between tonsillar lymphocytes and peripheral blood lymphocytes.