The effect of various surfactants on the production of adenocarcinomas by N-methyl-N'-nitro-N-nitrosoguanidine in the glandular stomach of rats was studied. Surfactants used were polyoxyethylene sorbitan monostearate, polyoxyethylene nonyl phenyl ether, and two types of alkylbenzenesulfonate. As a result, many cases of undifferentiated adnocarcinoma consisting of anaplastic glandular cells were induced in the experimental groups. Lymphatic invasion of cancer cells was found in 6 cases, and one metastasized to intestinal lymph nodes. On the contrary, though the control group (administered N-methyl-N'-nitro-N-nitrosoguanidine alone) revealed well-differentiated adenocarcinomas in many cases, neither lymphatic invasion nor metastasis was found. This fact would be due to these surfactants used as a vehicle for the chemical. By virtue of the strong penetrating property of surfactants, gastric carcinogenesis seemed to be enhanced.

View full abstract

Thymidine kinase (ATP: thymidine 5'-phosphotransferase, EC 2.7.1.21) was partially purified from Yoshida sarcoma cells by DEAE-cellulose column chromatography. The elution pattern showed two distinct peaks. The one was found in both normal and neoplastic cells and its activity was inhibited by the addition of cyclic AMP, whereas the other was found only in neoplastic cells and its activity was enhanced by the addition of cyclic AMP. The fractions containing the latter protein was reacted with cyclic AMP, and the protein was cleaved into several new fractions. The possible role of cyclic AMP in cell growth is briefly discussed.

View full abstract

Absorption spectra and partition coefficients between octanol and a buffer of pH 7.0 were measured on 32 kinds of compounds related to 4-nitroquinoline 1-oxide, including 17 strongly or weakly carcinogenic compounds and 15 noncarcinogenic compounds. The measured values were compared with the known carcinogenic activity. It was found that the carcinogenicity of 4-nitroquinoline 1-oxide and related compounds depended on the partition coefficient (P) and on the molar extinction coefficient at 260nm (ε₂₆₀) and the absolute value (|Δλ|) of the wave-length difference between the absorption maximum of the band nearest 260nm and 260nm. The value of Γ defined by the equation Γ=logε₂₆₀-log(|Δλ|+1) +logP corresponded well with the carcinogenicity of 4-nitroquinoline 1-oxide and related compounds. When plotted on a graph with axes of [logε₂₆₀-log(|Δλ|+1)] and logP, 31 of these compounds, excluding 4-hydroxyaminoquinoline 1-oxide, which was presumed to show the activity by metabolic conversion to an ultimate carcinogenic form, were distinctly divided into two groups of carcinogenic and noncarcinogenic compounds. The reason for the dependence of carcinogenicity on the absorption characteristic of a compound in the region of 260nm and on its partition coefficient was discussed from the electronic perturbation of DNA by the compound and from the permeability of the compound through a biomembrane.

View full abstract

Ferritins from hepatomas induced by 3'-methyl-4-(dimethylamino)azobenzene (3'-Me-DAB) were compared with ferritins from liver of rats of Wistar strain in which the original hepatomas developed. Three of five ferritin samples isolated from 3'-Me-DAB hepatomas migrated faster than rat liver ferritin and remaining two samples migrated normally in disc electrophoresis on polyacrylamide gels.
Electrofocusing column fractionation by carrier ampholytes with a narrow pH range was employed for the qualitative analysis of ferritins from 3'-Me-DAB-induced hepatomas and normal liver. The ferritins obtained from normal rat liver were fractionated into three heterogeneous peaks with pH values of 5.16, 5.24, and 5.29. On the other hand, ferritins from 3'-Me-DAB-induced hepatomas, which had fast mobility on electrophoresis, showed four heterogeneous peaks with pH values of 5.05, 5.16, 5.23, and 5.29. The appearance of acidic peaks of ferritin with a pH below 5.08 was characteristic as tumor ferritin in 3'-Me-DAB-induced hepatomas.
Immunological tests by immunodiffusion with rabbit antisera specific for rat liver ferritin showed no antigenic differences between normal and tumor ferritin, even if no such difference appears between fractionated peaks of tumor ferritin by isoelectric focusing.
Based on these findings, the biological meaning of the appearance of acidic peaks of ferritin in 3'-Me-DAB-induced hepatomas was discussed.

View full abstract

The present study was undertaken to elucidate the relationship between rat ascites hepatoma cells and mucopolysaccharides. Examinations were made on three types of the cell and the result was compared with control liver. The types of the cell used were the free-cell type ascites hepatoma AH-66F and Yoshida sarcoma, island-forming cell type AH-60C and a sub-strain LY-7 of Yoshida sarcoma, and a mixed cell type AH-109A. It was thereby found that there was a marked difference in mucopolysaccharides of these three types of cancer cells.
The chief constituent component of the mucopolysaccharide in the free-cell type cells was chondroitinsulfate-A, accompanied by a minute quantity of hyaluronic acid, heparan sulfate, and dermatan sulfate. In the island-forming type of the cells, heparan sulfate was the main component, with hyaluronic acid, dermatan sulfate, and chondroitinsulfate-A. In AH-109A cells, over 80% of the mucopolysaccharide was heparan sulfate, and hyaluronic acid and chondroitinsulfate-A were present only in a trace amount.

View full abstract

Conditioned media from various tissue culture sources brought about two effects on a myeloid leukemia cell line, M1 line; stimulation of cell growth and cell differentiation. There was no definite species specificity in the activity of the conditioned medium as far as the primary and secondary cultures used were concerned. However, established cell lines, regardless of the species and the character (leukemic or normal) produced only a very slight amount of differentiation-stimulating factor for M1 line cells. Proliferation of the two lines of lymphoid leukemia cells was also stimulated by the presence of conditioned medium, but no signs of differentiation were detected.

View full abstract

Macrophage-like cells, which developed spontaneously from a clonal line of mouse myeloid leukemic cells, were isolated as a subline. These macrophages had the same characteristics as those induced by conditioned medium in the original M1 line. The possibility of the "spontaneous" development of macrophages from a myeloblastic cell line is discussed.

View full abstract

The virus-induced cell surface antigen and the histocompatibility antigen on the cells of a transplantable Friend virus-induced tumor in the rat (RFT) were examined by the indirect immuno-ferritin method. Both antigens were present on the RFT cell surface, but absent on the envelope of Friend virus morphologically identified as type-C virus particles which were produced from the RFT cell membrane. Significance of the finding is discussed briefly.

View full abstract

Effects of hydrogen peroxide, Fenton's reagent, ferrous chloride, and ferric chloride on the carcinogenicity of 3, 4-benzopyrene in ddN female mice were studied. Although FeCl₂, FeCl₃, or H₂O₂ alone showed no effect, some accelerating effect in term of Iball index was observed by a single application of Fenton's reagent (H₂O₂+FeCl₂). Repeated applications of H₂O₂ markedly inhibited the carcinogenicity of 3, 4-benzopyrene. These results were discussed in connection with in vitro activation of 3, 4-benzopyrene by H₂O₂ or Fenton's reagent.

View full abstract

Thymomas closely resembling human thymoma developed spontaneously in 45% (30/67) of Buffalo rats over 12 months of age. The thymus weight of Buffalo rats significantly exceeded that of Wistar rats throughout the life span.

View full abstract

The cancerous change of acidic proteins in the chromatin of Ehrlich ascites tumor cells was studied by immunological methods. The acidic protein antigen was detected in the sera of Ehrlich ascites tumor-bearing mice. The sedimentation coefficient of the fraction containing acidic protein antigen was 4.21S.

View full abstract

Leukemoid reaction characterized by granulocytosis and splenomegalia in all BALB/cMk mice bearing seven different lines of tumors is described. Possible factors influencing this reaction are discussed.

View full abstract

Induction of mammary cancer in the Sprague-Dawley female rat by administration of 7, 12-dimethylbenz[a]anthracene was inhibited by intraperitoneal injection of Actinomycin-D and was not inhibited by Mitomycin-C. The possible mechanism of the inhibitory effect of Actinomycin-D was discussed.

View full abstract

The inhibitory effect of epithioandrostanoi (2α, 3α-epithio-5α-androstan-17β-ol) was observed on growth of transplanted estrogen-dependent mammary tumors in rats. A promoting effect was observed on growths of autonomous and androgen-dependent mammary carcinoma in mice.

View full abstract

The Epstein-Barr virus infection produced irregular and non-specific aberrations of chromosomes of the C-6 hematopoietic diploid cell line.

View full abstract

A study on 10 cases of lung cancer with asbestosis who were detected in this hospital and the survey of asbestos textile workers in Sennan district since 1957. The histological study of lung cancer revealed 3 adenocarcinomas and 7 squamous cell carcinomas.

View full abstract

Development of hapten-primed B-cells and carrier-primed T-cells was depressed by, treatment with 1, 12-dimethylbenz[a]anthrancene (DMBA). The depressed anti-hapten response of DMBA-treated mice was restored by the supplementation of carrier-primed T-cells. Accordingly, the primary target cell of the DMBA-induced immunosuppression was Thought to be the T-cell.

View full abstract

RFL cells, established from normal rat embryo lung, produced multinucleated giant cells when infected with murine leukemia virus. It appeared feasible to use the phenomenon for the titration of the viruses.

View full abstract