No abstract

Lung metastases were observed in 80% to 85% of rats bearing advanced malignant bone tumours (osteogenic osteosarcomas and angiosarcomas). These tumours were induced in 2-month-old Sprague-Dawley rats by inoculation of a colloidal suspension of radioactive cerium (144Ce) into the hind leg, in close contact to the bones of the knee joint. Twenty-eight rats were killed or died spontaneously shortly after detection of palpable tumours at the site of injection: the incidence of lung metastases was 73.3% and 53.8%, respectively, for osteogenic sarcomas and angiosarcomas, showing that most lung metastases are present at the time of diagnosis of the primary tumour. Tumour-cell kinetic parameters were studied in 49 rats bearing tumours following intraperitoneal injection of [3H]thymidine. The labelling index (LI) of the primary tumours was significantly lower in advanced tumours (7.2% for osteosarcomas and 10.1% for angiosarcomas) than than in tumors examined at the time of detection (12.2% and 13.5%, respectively). Mitotic indices (MI) of all tumours were less than 1%. From the curve of the percentage of labelled mitoses (PLM) at different times after [3H]thymidine injection, Ts (6.5 h) and TG2 (1.75 h) were determined. TC and TG1 were also evaluated (18 h and 9.25 h, respectively). These results show that malignant bone tumours induced in rats with 144Ce may be a good model for human osteosarcomas and may be useful in studying the numerous problems in the therapy of malignant bone tumours in man.

Summary.-A technique is described for the induction of metastasizing bone tumours in rats by local inoculation of 144cerium. Bone sarcomas develop in 9000 of the animals and 74%0 of these had lung metastases. The tumours can be easily cultured and maintained by serial transplantations. Preliminary data of clinical, histological and kinetic characteristics of these bone tumours are given.To ANSWER the multiple questions which arise in the treatment of human osteosarcoma, i.e. effect of radiochemoimmunotherapy, prevention of lung metastases, diagnostic procedures and pathophysiological characteristics, there is a particular need for experimental tumour models.

The clinical course of 201 patients with malignant non-Hodgkin-lymphomas was analysed according to the Kiel classification. The five-year survival rate of 133 patients with lymphomas of low grade malignancy was 63% in comparison to 23% out of 68 patients with lymphomas of high grade malignancy. Radio- and chemotherapy were used in a different way. Patients with centrocytic-centroblastic lymphomas had the best porgnosis, which was not influenced by the stage of the disease. The poorest prognosis was observered in patients with lymphoblastic lymphomas. These results support the importance of a classification of malignant non-Hodgkin-lymphomas which is not only based on morphological criteria.

Two hundred and seventy apparently healthy adult subjects from Afghanistan, mainly from the central and eastern parts of the country, were subjected to a lactose tolerance test. The change of blood glucose from the fasting concentration at 20 min after the administration of lactose showed a bimodal distribution. Forty-seven subjects had a rise of blood glucose concentration of more than 1.1 mmol/l and were classified as persistence of high intestinal lactase activity (PHILA), a term which lays emphasis on the fact that high lactase activity in the adult is an unusual state whose prevalence in some populations requires explanation. In the Afghan sample there were no significant differences of the frequency of PHILA in different ethnic groups.