Takeshi Kohno

Computer Aided Analysis of Cell-Cycle Phase from Cytophotometric Histogram

A method for estimating, from cytophotometric data, the proportion of cells in three different phases of the cell cycle is proposed. Computation is done by means of determining seven parameters in the approximate function for the fluorescence intensity histogram. The proportion of cells in the GI, S, and G2-M phases, obtained by this method, was found to be reliable.

Successful Combination Chemotherapy (Cisplatinum, Vinblastine, and Bleomycin) in the Treatment of Medulloblastoma Disseminated by Cerebrospinal Fluid: Case Report

A case of successful combination chemotherapy using cisplatinum, vinblastine, and bleomycin (PVB therapy) to treat medulloblastoma disseminated by cerebrospinal fluid is presented. In this case, a locally recurrent tumor and several disseminated tumors were seen to decrease in size on CT examinations. Pain in the lower extremities and urinary incontinence improved during three courses of PVB therapy administered during a period of 9 weeks. These results suggest that combination PVB therapy may offer one of the treatments of choice for recurrent or disseminated medulloblastoma.

Intraoperative radiation therapy for glioblastoma multiforme

In order to obtain a local cure of glioblastoma, the first therapeutic step of therapy should be an intensive local treatment. Intraoperative radiation therapy has been developed in order to sterilize the remaining malignant remnants by a single massive dose of high energy electron beam. In the limited delivery of less than 6000 rad at a conventional dose rate for necrosis of the normal brain, intraoperative radiation therapy becomes a logical local treatment for brain tumors. Advantages claimed for intraoperative irradiation are presented as precise demarcation of the target volume under direct vision, minimum damage to surrounding brain tissues, and a high target absorbed dose of 1500 to 2000 rad per 4–8 minutes. With a range from 8 to 20 megavolts, corresponding to an absorbed dose of between 1000 and 2000 rad, intraoperative radiation therapy was performed on 17 patients. In 13 of these, almost complete resectability of the tumor was expected, and a two-year survival rate of 58.3% was obtained. In 4 other cases with a widespread deep-seated tumor, the survival rate after 1 year was 50% and none survived 2 years. The results apparently indicate that adjacent marginal areas to the almost complete removal should be irradiated with a sufficient dose to sterilize the remaining malignant remnants.

Pulse-cytophotometric Studies on Experimental Brain Tumor under the Effect of Chemotherapeutic Agents, Microwave Irradiation and Hyperthermia

physical condition was investigated for establishing the optimal regime of brain tumor synchronization as pretreat ment for radiotherapy. Cultured Ce strain was treated for 72 hours with Vincristine, Vinblastine, ACNU, BCNU, 5-FU, Methotraxate, Bleomycin, hyperthemia or microwave irradiation. The cell cycle distribution was analysed by the histograms of pulse-cytophotometry with DNA specific fluorescent stain of ethidium bromide in cell suspen sion. The quantitative evaluation of cell cycle phase was obtained using a computerized mathematical model. Potent synchronization in the G2-M phase was observed in the group treated with Vincristine, Vinblastine, ACNU and BCNU. In the Vincristine and ACNU-treated group, G2-M phase accumulation increased gradually during 72 hrs. Maximum level of G2-M phase was 47.6% of diploid cell population by 72 hrs-contact with Vincristine, and 47.2% by ACNU (control 10%). In the Vinblastine and BCNU-treated group, G2-M phase-accumulation in creased rapidly during 24 hrs. and then the accumulated cells in G2-M phase became dead within 72 hrs. Hy

Secondary Tumors of the Skull, the Meninges and the Brain in Children

Secondary tumors of the skull, the meninges and the brain are said to be rare in children. According to the Annual of the Pathological Autopsy Cases in Japan of 1971 and 1972, there were 173 cases of these secondary tumors in children while there were 196 cases of primary brain tumors. It is, therefore, concluded that these secondary tumors are rather frequent. Fifty-one fatal cases of secondary tumors of the skull, the meninges and the brain in children treated in the National Cancer Center Hospital (Tokyo) from 1962 to 1974 were studied and were their diagnosis and the treatment discussed, with special emphasis on the indication of surgical removal. These included 18 leukemias, 13 neuroblastomas, 9 retino-blastomas, 8 sarcomas, 2 malignant lymphomas and I embryonal carcinoma. Leukemia: The leptomeningeal infiltration existed in most cases. Diagnosis was made by the evidence of leukemic cells in the cerebrospinal fluid. The intrathecal injection of methotrexate with or without whole-brain irradiation was effective in first course, but was not effective in secound or third courses. The autopsy findings indicated that the typical pattern was the diffuse infiltration of leukemic cells in the leptomeninges and in the subarachnoid space, and multiple intracerebral hematomas accompanied by leukemic cells were occasionally observed. Neuroblastoma : Metastatic skull tumors were palpated in all cases. Autopsy findings revealed that metastatic lesions existed not only in the skull but also in the meninges. Radiotherapy was applied without sufficient effect. Retinoblastoma : The leptomeningeal infiltration with the early consciousness disturbance was characteristic. Intrathecal injection of Methotrexate was not effective. Autopsy findings indicated that tumor cells infiltrated along the optic nerve into the intracranial subarachnoid space, spread diffusely and formed solitary lesions in the hypothalamus, the cerebellum or other intracerebral regions. Our studies suggest that indication of the neurosurgical removal of tumors is limited for most cases. Early diagnosis and the care under pediatricians and neurosurgeons will bring better prognosis by intensive treatment with chemotherapy, radiotherapy and decompressive operation.