Histological studies of the effect of intra-operative irradiation on osteosarcoma

At the Department of Orthopaedic Surgery of Kyoto University Hospital, intra-operative radiotherapy by the high dose electron irradiation has so far been used in treating patients with osteosarcoma. The dose distribution was calculated by CT-number so that the focus was subject to at least 80% of the irradiation doses and the surgically opened lesion was irradiated with 5,000 rad of 12-26 MeV electron beams. In order to accurately assess its therapeutic effect, histological studies were conducted on 9 patients who underwent en bloc resection or amputation following irradiation treatment for osteosarcoma. Method The excised specimen was sagittally cut in half and was fixed in 10% neutral buffered formalin. The specimen was cut into 5 mm thick sections corresponding to CT cross sections. At the border region between irradiated and non-irradiated fields, specimens were prepared using sagittal sections to compare the histological findings of both fields. After all specimens were carefully macroscopically examined and then photographed with soft-X-ray film, some of them were prepared as non- delimed specimens in polyester resin and were observed by contact microradiography and fluorescent microscopy. The remaining specimens after deliming in Plank - Rychlo solution were sliced to 4-8 micron thick for study as large specimen stained with hematoxylin and eosin. Four patients had been administered tetracycline 3 days preoperatively. Results Histologically the changes of the specimens were evaluated using the Oohoshi and Shimosato 's criteria for the histological effects of irradiation. In two of the 9 patients, who had received unidirectional irradiation, the survival of Grade 2a-2b tumor tissue was observed in the superficial layers both inside and outside the periosteum. Six patients who were irradiated from both sides or three directions, showed complete necrosis in extremely small areas of Grade 2b-3 change of tumor cells. Only one of these 9 patients had a local recurrence after the irradiation. Marked fluorescence was observed in the recurrent tissue by tetracycline labeling, but no fluorescence was observed in any of the other cases in the tumorous tissues which had fallen within the range of irradiation. These findings strongly suggest that intra-operative irradiation is extremely effective in controlling local osteosarcoma lesion in the extremities.     

Experimental studies on pancreatic islet xenotransplantation--effect of irradiation on xenografts survival

The purpose of the present study was to assess the effect of Total Body Irradiation (TBI) and Total Lymphoid Irradiation (TLI) on pancreatic islet xenografts survival. Wistar rats rendered diabetic by intravenous injection of streptozotocin were used as recipients. Golden hamsters were used as islet donors. Pancreatic islets were isolated by the collagenase digestion method. Twelve hundred islet were transplanted into the portal vein of diabetic rats. In untreated controls, the mean graft survival time was 2.9 +/- 0.6 days (n = 7). In TBI of 400 rad treated group, three out of 9 recipients accepted islet xenografts for more than 80 days. TLI of 1200 rad also significantly prolonged graft survival period (30.3 +/- 11.7 days, n = 7, p less than 0.01). Rat anti-hamster lymphocytotoxic antibody titers began to rise on the second day after islets xenografting in untreated and TLI of 400 rad treated recipients. While, elevation of cytotoxic antibody titers was completely suppressed in spite of occurrence of the rejection in TLI of 800 and 1200 rad treated recipients. This may indicate that xenograft rejection in TLI of 800 and 1200rad treated recipients was mediated by cellular immunity rather than humoral immunity.     

Experimental studies of the effect of bupivacaine on peripheral nerves

0.5% Bupivacaine was administered around the sciatic nerve of rabbits by means of a catheter, over a period of ten days. Twenty nerves showed no histological changes, but in three there were areas of demyelination and axonal degeneration, especially near the surface of the nerve. However, similar changes occurred in two out of six nerves to which normal saline was administered instead, and it is suggested that the damage may have been caused by mechanical trauma from movement of the catheter.     

Experimental studies on effects of total-body and local hyperthermia on metastases in mice

To study the effects of total-body hyperthermia (TBH) and local one (LH) on tumor metastases in animal experiments, heat was delivered to Lewis lung carcinoma (LLC)-bearing C57BL/6 mice and mouse ascites hepatoma-134 (MH-134)-bearing C3H/He mice, by water bath immersion systemically and locally. Rectal temperature in TBH was kept at 40 or 42 degrees C, while intratumor temperature in LH, at 40, 42, or 43 degrees C, respectively for 30 min. Also backgrounds of spread of lung metastasis of LLC in the case of TBH at 42 degrees C have been investigated as well as strategic preventive measures for it. The following results were obtained: The growth of primary LLC and MH-134 tumors was inhibited by TBH and LH at 42 degrees C and LH at 43 degrees C. The lung metastases of LLC increased by TBH at 42 degrees C. The lymph node metastases of MH-134 decreased by LH at 43 degrees C. The increase of lung metastases of LLC by 42 degrees C TBH occurred within 24hr after the session, presumably due to the increase in intravascular invasion of tumor cells and accelerated implantation of them according to histological changes of lungs. The observable tendency toward lung metastases continued for 48hr after treatment, coincidentally with distinctness in observation of histological changes. The increase mentioned above could be prevented by combined use of 42 degrees C TBH with anticancer drugs, as cis-diamminedichloroplatinum II or mitomycin-C. This combination resulted in further inhibition of tumor growth of primary LLC also, than non-combined 42 degrees C TBH. Considering the above facts, combined treatment of TBH with anticancer drugs is believed much valid clinically, in preventing metastases and making higher exertions of antitumor effects.     

毫米波对周围神经部分损伤后神经修复的影响

目的探讨毫米波对周围神经部分损伤后神经修复的影响.方法SD雄性大鼠48只,制成左侧坐骨神经钳夹伤模型,随机分为治疗组和对照组.治疗组在神经损伤24 h后,将毫米波辐射损伤部位,每周5次,每次30 min.观察指标：从运动功能、电生理、组织学等方面观察其对大鼠坐骨神经部分损伤后神经修复的影响.结果治疗组在术后2、4、6周中运动神经传导速度均高于对照组,运动功能恢复时间明显短于对照组,有髓神经纤维横截面积均大于对照组.电镜观察,对照组在术后2周的神经变性程度比治疗组严重,治疗组在术后4、6周的神经再生数目和成熟度均优于对照组.结论毫米波能够促进周围神经损伤的修复和功能恢复.