✓ Since the development of a specific monoclonal antibody against the thymidine analogue bromodeoxyuridine (BUdR), many investigators have used intravenous infusion of BUdR to estimate the proliferative potential of human brain tumors. However, side effects such as the induction of cell mutation, latent virus promotion, or inhibition of cytodifferentiation cannot be ignored, and thus many workers hesitate to use it in patients, especially those with hepatic disease or of reproductive age. Furthermore, if BUdR remains in the deoxyribonucleic acid of tumor cells after injection, analysis of the effect of chemical and radiation therapy may not be evaluated correctly. In this report, in vitro BUdR labeling with an anti-BUdR antibody is compared with the in vivo methods described by previous authors. This method appears to be useful for determining the S-phase fraction of human brain tumor. It was more rapid, and was simple, safe, and reproducible as compared to the intravenous infusion method.
Takafumi Nishizaki, Tetsuji Orita, Masahide Saiki, Yasuhiro Furutani and Hideo Aoki
Tetsuji Orita, Takafumi Nishizaki, Toshifumi Kamiryo, Kunihiko Harada and Hideo Aoki
✓ The sequential changes in microvascular architecture following local cold injury in rat brains were studied post mortem by scanning electron microscopy and the vascular casting method. The findings were compared with the results of immunohistochemical studies of injured endothelial cells using the bromodeoxyuridine (BUdR) and anti-BUdR monoclonal antibody technique.
Repair of the microvascular architecture had begun by the 3rd day after injury, with hematogenous cells and reactive astrocytes present in the edematous brain participating in the regenerative process. The normal microvascular architecture was reconstructed starting from the edge of the lesion nearest to the brain surface. On the other hand, in the most severely injured part of the brain surface, newly formed microvascular architecture appeared, resembling that of the developing fetal and newborn rat cortex. Seven days after injury, the entire microvascular architecture in the region of the lesion had been reconstructed.
Takafumi Nishizaki, Tetsuji Orita, Yasuhiro Furutani, Yukihide Ikeyama, Hideo Aoki and Kohsuke Sasaki
✓ Cell proliferation potential was assessed by measuring the labeling indices of the monoclonal antibody Ki-67 and of 5-bromodeoxyuridine (BUdR), and the cellular deoxyribonucleic acid (DNA) content in 48 human brain tumors. The diagnostic and prognostic value of flow-cytometric DNA analysis was also evaluated using ethanol-fixed paraffin-embedded BUdR-labeled specimens; these were the same specimens as were used for measuring the BUdR and Ki-67 labeling indices. Both the Ki-67 and the BUdR labeling indices correlated with the degree of malignancy estimated from conventional histological preparations. The Ki-67 labeling index was 1.7 times greater than the BUdR labeling index. The relationship of DNA aneuploidy to the labeling indices or to morphology in cases of glioma was examined. All of the tumors with an aneuploid line corresponded to malignant glioma classified by histological criteria, although malignant glioma did not always show DNA aneuploidy. In addition, the cases with aneuploid lines showed high BUdR and Ki-67 labeling indices. The cell kinetic data, which indicate the biological character of tumors, allowed prediction of the prognosis of the patients with gliomas. In contrast, despite the presence of an aneuploid line, three of 13 meningiomas showed a benign histological pattern without an aggressive clinical course, and neither the Ki-67 nor the BUdR labeling index was high. These results indicate an unequivocal relationship between DNA aneuploidy and clinical behavior; in general, both labeling indices may prove to be objective indicators of the outcome of patients with brain tumors.
Koji Kajiwara, Takafumi Nishizaki, Tetsuji Orita, Hisato Nakayama, Hideo Aoki and Haruhide Ito
✓ A silver colloid staining technique for identifying nucleolar organizer region-associated proteins (Ag-NOR's) was applied to 51 human gliomas. These comprised 20 glioblastomas multiforme, 15 anaplastic astrocytomas, and 16 astrocytomas, in which the mean numbers of Ag-NOR's per cell (± standard error of the mean) were 2.51 ± 0.12, 2.01 ± 0.10, and 1.76 ± 0.06, respectively. Significant differences among these were recognized, and the mean number of Ag-NOR's paralleled the degree of histopathological malignancy. In 16 cases, studies were performed of the number of Ag-NOR's and the S-phase fraction by in vitro labeling using anti-bromodeoxyuridine monoclonal antibody. A linear relationship was demonstrated between these two factors (r = 0.857, p < 0.001), although some scatter was seen. In 32 adult patients, the correlation between the number of Ag-NOR's and the prognosis was estimated. The results demonstrated that the group containing patients with less than 1.80 Ag-NOR's per cell had a better prognosis than the group with 1.80 Ag-NOR's or more. Thus, the number of Ag-NOR's reflected the degree of histopathological malignancy, S-phase fraction, and prognosis. Silver colloid staining for Ag-NOR's is a simple, rapid, and reproducible method for estimating the proliferative potential of human gliomas without requiring a complicated technique.
Takafumi Nishizaki, Tetsuji Orita, Koji Kajiwara, Norio Ikeda, Noboru Ohshita, Hisato Nakayama, Yasuhiro Furutani, Yukihide Ikeyama, Tatsuo Akimura, Toshifumi Kamiryo and Haruhide Ito
✓ There are no previous reports correlating the in vitro bromodeoxyuridine (BUdR) labeling index (LI) with the clinical outcome in patients with brain tumors. The reliability of the LI as a predictor of patient survival or recurrence was examined in this study of 66 human brain tumors (19 gliomas, 18 meningiomas, and 29 others). Anti-BUdR staining was performed on surgically extirpated tumor tissue that had been treated with BUdR as previously described. Correlation of the BUdR LI with patient survival or tumor recurrence rate was carried out by the method of Kaplan and Meier. Deoxyribonucleic acid (DNA) aneuploidy was estimated in 52 cases.
The results of this study indicate that BUdR LI values correlated well with the clinical course of patients with brain tumor. In comparison with patients with higher LI's, there was both a significantly higher survival rate for tumors other than meningiomas and a higher recurrence-free rate for meningiomas in patients with LI's of less than 4% and 1%, respectively. Although there was a tendency for patients without tumor aneuploidy to show better survival data than the others, no statistical difference was observed. These results suggest that the in vitro BUdR labeling method is reliable for prediction of a patient's prognosis, whereas prognosis on the basis of DNA aneuploidy alone is uncertain.