Andreas P. Kyriazis

Maxillary ameloblastoma with intracerebral extension: Report of a case

Abstract A 73-year-old Negro woman with an aggressive ameloblastoma was treated surgically. All attempts to remove the tumor completely were unsuccessful. From its original site in the left maxilla, the tumor extended upward, destroyed the base of the skull, and infiltrated the brain, replacing the temporal lobe of the brain. The extensive squamous metaplasia of the stellate reticulum, its focal hypercellularity, and the predominance of the epithelium over the stroma evidenced in certain areas of the tumor may be considered features related to the aggressiveness of this neoplasm. Ameloblastomas are rare neoplasms of the jaws. They are of clinical importance because they resist treatment and have a tendency to recur and invade the surrounding tissues. If uncontrolled, they may extend to the base of the skull and even infiltrate the brain.

Histopathologic Evaluation of Response to Treatment of Human Tumors Grown in the Nude Mouse

The histopathologic changes following chemotherapy treatment of a number of human tumors grown in nude mice were evaluated. On the basis of the histopathologic profile, three response levels were recognized--a mild response, a moderate response and a severe response. Severe response was characterized by arrest of cell division and profound nuclear-cytoplasmic degenerative changes. Regrowth of effectively treated tumors originated in clusters of cells most probably representing resistant tumor cell clones. Histopathologic changes represent a sensitive indicator of the response of nude mouse grown human tumors to anticancer agents. Availability and correct interpretation of the post-treatment histopathologic picture is of importance in selecting the proper combination treatment which would maximize tumor response.

Response to ionizing radiation of human bladder transitional cell carcinomas grown in the nude mouse.

The sensitivity to ionizing radiation of three human bladder transitional cell carcinomas grown in the nude mouse was investigated at four different radiation levels, 500, 1,000, 2,000 and 4,000 rad. Each tumor line exhibited a response pattern which reflected to a certain degree tumor differentiation and growth rate in the nude mouse. Exposure to 1,000 rad was the minimum amount of radiation required to produce a distinct, although transient, tumor response in all three tumor lines characterized by a growth delay of 3-4 weeks, whereas maximum tumor response was observed at the 4,000 rad radiation level. These studies would permit a better understanding of the behavior of human bladder cancer to ionizing radiation and may further facilitate efforts at identifying effective radiosensitizing agents that may result in maximizing tumor response.

Migratory Inhibition of Sensitized Peritoneal Macrophages by Tumor-Specific Transplantation Antigen in Morris Hepatoma 5123

Summary The inhibition of the migration of sensitized peritoneal macrophages has been used in studying a specific tumor transplantation antigen in Morris hepatoma 5123 and its absence in normal liver tissue from which the tumor originated. Migration of peritoneal macrophages sensitive to the tumor was greatly inhibited by the addition into the incubation medium of a fraction of the solubilized tumor cell membranes. Use of solubilized membranes from normal liver cells were much less effective in inhibiting the migration of sensitized peritoneal macrophages. The specificity of the inhibition was demonstrated by using decreasing concentrations of the tested antigens. By this method it was possible to reach a point where the test was reflecting only the tumor-specific activity.