Zeitschrift fur Krebsforschung und klinische Onkologie. Cancer research and clinical oncology最新文献

The effect of Bleomycin on the semiconservative replication of mouse nuclear DNA has been studied. When asynchronously dividing mouse fibroblasts (L-cells) were grown in the presence of 5-bromodeoxyuridine (25 mg/l medium) for 18 h, three hybrid DNA bands with densities of 1.722, 1.752, and 1.761 kg/l appeared after caesium chloride density gradient centrifugation of nuclear DNA. In cells exposed to Bleomycin (100 mg/l) however, replication of satellite DNA is more strongly inhibited than is the replication of the main band DNA; preferentially the thymidinerich hybrid duplex at 1.761 kg/l could no longer be detected.

Substitution with a methyl group at the C-atoms adjacent to nitrogen of N-nitroso-N-methylbenzylamine (NMBA) results in a considerable reduction LD 50: N-nitroso-N-methylbenzylamine : 18 mg/kg (Druckrey et al., 1967) N-nitroso-N-methyl-(1-phenyl)-ethylamine (I) : 600 mg/kg N-nitroso-N-methyl-2-(2-phenyl)-propylamine (II) : 2100 mg/kg N-nitroso-N-ethyl-benzylamine (III) : 250 mg/kg Substitution with a methyl group at the methylene of the moiety of NMBA (NMPEA I) reduces also the carcinogenic activity, but it produces in all animals carcinomas of the oesophagus and the pharynx; the replacement of both H-atoms by methyl groups (NMPPA, II) causes under the condition chosen no development of tumors, because for the activation step no proton is available. The exchange of N-methyl by N-ethyl of NMBA (NEBA, III) however produces no change in the carcinogenicity.

Pleural effusion cells from two patients with stage IV Hodgkin's disease have been cultured continuously in diffusion chambers in mice and studied by electron microscopy after a culture period exceeding 100 days. Cell identity and monoclonal growth in culture has been documented by marker chromosomes (Hossfeld and Schmidt, 1978). These cultured cells grow in close connection, projecting pseudopode-like processes into the intercellular spaces. Most nuclei are lobulated. They always are of low electron density with a norrow rim of condensed chromatin confined to the nuclear membrane. One large prominent nucleolus and up to four smaller nucleoli are found. Nuclear pockets in case 1 and deep cytoplasmic invaginations into the nuclear area in both cases frequently occur. In the cytoplasm, besides microtubuli and fibrils, the Golgi apparatus and mitochondria are the predominant organelles. Most mitochondria appear to be dilated containing fragmented cristae. Free ribosomes and polysomal aggregates are randomly distributed. The ratio nucleoplasm:cytoplasm, on the average, is 0.7 in both cases and the cell diameters lie distinctly above those of lymphocytes. At the electron microscope level these cultured monoclonal cells of Hodgkin's disease are not distinguishable from those described in genuine Hodgkin material. Their probable origin and apparent relation to true histiocytic lymphoma cells will be discussed.

Statistically evaluating the influence of a histological grading, respectively of morphological differences on prognosis of nephroblastomas and neuroblastomas, better chances for survival become evident not only for earlier clinical stages, but also for nephroblastomas with high differentiation, or neuroblastomas with signs for differentiation. Only for neuroblastomas a relevant predeliction of tumors with signs of differentiation for the early clinical stage I is present. Combined subclassification according to clinical stages and histological grades results in 3 risk groups with different chances for survival. These 3 groups may play a role for specific therapeutic considerations.

Cells from 14 human breast carcinoma were obtained by aspiration biopsy and used for in vitro cultivation. Growth could be observed in three cultures, which were derived from solid, partly adenoid growing tumors with metastases in the axillary nodes. The growth started after 2--6 days in culture and lasted 2--4 weeks. No permanent line could be established.

The carcinogenic effectiveness in rats of three cyclic nitrosamines administered at two doses separated by a factor of five has been studied. All three compounds showed a response at the lower dose quite different from that at the higher dose. One, 2,6-dimethyl-dinitrosopiperazine, was only a little less effective at the lower dose than at the higher dose, giving 100% nasal turbinate tumors, but only 33% esophageal tumors, compared with 100% esophageal tumors at the higher dose. 3,4-Dichloronitrosopiperidine gave 100% incidence of esophageal tumors at the higher dose. At the lower dose, survival of the rats was very much better, some living 80 weeks, and, in addition to the esophagus, there were tumors of several organs including forestomach, tongue, and nasal turbinates. On the other hand, 2,6-dimethylnitrosomorpholine was a very much weaker carcinogen at the lower than at the higher dose, only six animals dying with tumors, compared with 100% incidence at the higher dose. However, the pattern of mortality of rats given the lower dose of dimethylnitrosomorpholine was similar to that of rats given the lower dose of dichloronitrosopiperidine.

A correlation study between mean nitrate nitrogen levels (ppm) in drinking water samples (N = 1389) of Chilean urban areas and age-adjusted death rates per 100 000 population from stomach cancer, by province or region and sex, was made. Drinking water samples from all provinces (N = 25) had a weighed mean of 1.446 ppm (S.E.M. 0.068) with a range of 0.00--30.00 ppm. Nitrate nigrogen levels showed a positive but not significant association with male death rates. The correlation coefficient was +0.0335. Similarly, such levels did exhibit a positive but not significant correlation with female death rates (r = +0.0486). When NO3-N levels and male (r = +0.1367) or female (r = +0.1143) death rates were studied, by region, positive but insignificant correlations were detected. Using Cochran's approximation, mean nitrate nitrogen levels in drinking water samples from six provinces with 50% of the Chilean population (period 1953--55 versus 1973--75), showed a decrease from 1.835 to 1.291 ppm, but there was no significant difference (t = 1.32) between the two values, except in samples from Santiago Province (t = 2.11, P less than 0.05). Provinces (south central area) showing the highest gastric cancer mortality rates in the world for females (up to 40.8/100,000), and ranking second for males (up to 84.1/100,000), exhibited a very low mean level (0.825 ppm).

Unlabelled: The investigation of 400 adult mice had the objective to find out 1. The influence of splenectomy on genesis and growth of a benzpyrene-induced sarcoma and 2. The behavior of B- and T-lymphocytes under the influence of splenectomy.

Results: 1. A significantly lower number of tumors developed in splenectomized animals (28.5%) as compared to controls (49.5%). 2. A significant decrease of B-lymphocytes and an increase in T cells after splenectomy were found in the peripheral blood. 3. The examination of the tumor marginal zone showed a decreased number of B-lymphocytes and an increase of T-lymphocytes, while the total count of round cells remained unchanged. These results are discussed and compared with results of other authors.

Unlabelled: The investigations of 400 adult hybrids from A/Jax fem. BALB/c male were aimed at answering the following questions: 1. What is the influence of a generalized graft-versus-host-reaction (GVHR) on the induction and growth of benzpyren-induced sarcoma? 2. What is the behavior of B- and T-lymphocytes during GVHR, and during induction and growth of benzpyren-induced sarcoma? 3. Which are the deductions to be drawn with regard to the effect of B- and T-lymphocytes during tumorigenesis and tumor growth?

Results: 1. The number of tumors was significantly greater in the GVHR animals (74.5%) than in the controls (49.5%). 2. A significant decrease of T-lymphocytes and increase of B-lymphocytes during GVHR were found in the peripheral blood. 3. The examination of the tumor marginal zone showed a marked decrease of the total round cell count and the T cells, while the count of B-lymphocytes remained uninfluenced. These results are discussed and compared with results of other authors.

Several types of cultured cells release glycolytic enzymes into their suspending medium. This effect is most obvious with tumor cells, especially with their ascites forms. Erythrocytes do not release glycolytic enzymes. The total extracellular phosphoglucose isomerase activity consists of two components. One part is dissolved in the medium, the other one is sedimentable at 150 X g together with the cells. The latter seems to be localized at the cell surface. At densities of about 10(6) cells/ml maximum activity in the medium is reached within 5--10 min. After that no further release of enzyme activity can be observed. Serum reduces the rate of enzyme release considerably. This effect can be reversed by washing with protein free media. Treatment with trypsin leads to high extracellular phosphoglucose isomerase activities of the cells which originally show low external enzyme activity. Erythrocytes do not show any effect with trypsin, ascites tumor cells do not alter their high extracellular enzyme activity. At a density of 10(5) cells/ml, Yoshida acites tumor cells, cultured in vitro, release about 12% of originally intracellular phosphoglucose isomerase activity by 5 elutions with fresh medium. The process of enzyme release shows a certain selectivity in respect to different glycolytic enzymes. Aldolase exhibits the highest activity in the medium in relation to its homogenate activity.