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We investigate the characteristic deformation behavior of rubber with carbon black (CB) filler. The deformation behaviors of a plane strain rubber unit cell containing CB fillers under monotonic and cyclic strain are investigated by computational simulation with a nonaffine molecular-chain network model. The results reveal the substantial enhancement of the resistance of the rubber to macroscopic deformation, which is caused by the marked orientation hardening due to the highly localized deformation in the rubber. The disentanglement of the molecular chain during the deformation of rubber results in the magnification of the hysteresis loss, i.e., the Mullins effect, occurring in stress–stretch curves under cyclic deformation processes. The increase in volume fraction and in aggregation of the distribution of CB substantially raises the resistance of the rubber to deformation and hysteresis loss. The effect of the heterogeneous distribution of the initial average number of segments of molecular chains on the hysteresis loss has been clarified.

We invistigate the characteristic deformation behavior of rubber with carbon black filler. The deformation behaviors of plane strain rubber unit cell contained fillers under combined monotonic and cyclic straining are investigated by computational simulation with the nonaffine molecular chain network model. The results reveal the substantial enhancement of resistance to the macroscopic deformation, which is caused by the remarkable orientation hardening due to the highly localized deformation in the rubber. The disentanglement of molecular chain during the deformation of rubber results the magnification of the hysteresis of the macroscopic stress-strain relations under cyclic straining. Furthermore, we discussed an additional strengthening and hysteresis loss caused by the increase of the volume fraction of filler, the heterogeneity of the distribution of filler and the heterogeneity of initial average number of segments of modecular chains.

症例は50歳男性で, 労作時呼吸困難を主訴に入院した. 心臓超音波検査・CTで心タンポナーデおよび右房内腫瘤を認めた. 心嚢穿刺を行い多量の血性心嚢液を排液した. 精査の結果心臓悪性腫瘍が疑われ転移巣を認めなかったため, 24日後に手術を施行した. 体外循環下に右房壁を含めて腫瘍を全摘出し, 右房は馬心膜で再建した. 洞結節は切除せざるを得ずペースメーカー植え込み術も併せ行った. 病理組織診断は右房原発血管肉腫で, 切除断端はすべて陽性であったため, 術後放射線療法を計50Gy施行した. 術後14カ月を経過する現在, 再発, 転移を認めず元気に社会復帰している. 本疾患は非常に予後不良で, 平均余命は6カ月以内である. 遠隔転移が認められない場合には早期に腫瘍を摘出し, 不完全切除に終っても術後放射線療法が奏効すれば延命効果が期待できる.

A 76-year-old female patient with diarrhea and lower abdominal pain was found by barium enema to have an ileocecal tumor. Endoscopic appearance was suggestive of malignancy; however, biopsy revealed v

✓ 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.

✓ 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.

A rare case of extradural nasal and orbital extension of malignant glioma is presented. The development of malignant changes was observed during 10 years. The mode of transdural extension was via the olfactory nerve, where it was directly destructive in all four cases that have been reported to date. The biological malignancy of transdurally extending glioma is also described.

It is still unknown when and in which area endothelial regeneration occurs after brain injury, and to what extent such changes depend on the severity of the injury. We have, therefore, studied bromodeoxyuridine (BrdU) uptake by regenerating endothelial cells in two different groups of rats given cold lesions using immunohistochemistry employing anti-BrdU monoclonal antibody, anti-factor VIII-related antigen antibody and anti-glial fibrillary acidic protein antibody. The earliest evidence for the presence of BrdU-positive endothelial cells (BrdU + end) was observed at 2 days after injury, the injured endothelial cells regenerating from the edge toward the center of the lesion in both groups. We considered that edema fluid could act as an important factor, since at 2 days post-injury BrdU + end were not in contact with macrophages and were always found in Evans blue-stained areas. Study of endothelial cell kinetics also confirmed that the repair of injured endothelial cells was intimately involved in the reconstruction of the blood-brain barrier, since the time of disappearance of BrdU + end coincided with the disappearance of Evans blue-stained areas. The difference in the process of endothelial regeneration was first apparent on the 3rd day, there being no difference at 2 days.

Small-bowel obstruciton due to gastric bezoar is rare. This case was a 73-year-old gastrectomized woman who was admitted with nausea and abdominal pain and was suspected of having acute pancreatitis. She ate a lot of persimmons several days before the onset of her symptoms and was diagnosed as having gastric bezoar by gastrofiberscopy. Three weeks later severe abdominal pain and distension appeared abruptly. An upper gastrointestinal contrast series demonstrated small-bowel obstruction with a bezoar and emergent operation was performed. A hen-egg-sized bezoar was impacted in the jejunum 30 cm distal from Treitz's ligament. It was removed through enterotomy.Fifteen cases of small-bowel obstruction due to gastric bezoars including this case have been reported during the last 10 years. In all cases conservative treatment failed and laparotomy was necessary. In gastrectomized patients like this case, it is probable that dislodgement of gastric bezoars caused small-bowel obstruction. Therefore, prophylactic measures such as dietary to prevent bezoar formation are important.

It has not been determined when and in which area regeneration of the cerebral endothelium occurs after brain injury (Orita et al. 1988). We therefore studied bromodeoxyuridine (BrdU) uptake by regenerating endothelial cells in two different groups of rats given cold lesions using immunohistochemistry employing anti-BrdU monoclonal antibody, anti-factor VIII-related antigen antibody and anti-glial fibrillary acidic protein antibody.

✓ 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.