Biomedical subjects

E M Blaufuss

Publications and source records attributed to E M Blaufuss.

4 recordsLinked to original sources

PubMed1980

Differences in carcinogenicity after transplacental and postnatal administration of drugs and pesticides.

Comparative studies of the carcinogenic activity of procarbazine, methylphenylnitrosourea and ethylenethiourea after transplacental and postnatal administration showed that there were marked differences in frequency and spectrum of tumors induced. Possible causes of these differences are briefly discussed. It is suggested that transplacental experiments can provide special advantages in testing drugs and environmental chemicals for potential carcinogenicity and should be included in test programs.

Animals↗

PubMed1979

Tumors of the rat kidney induced by nitrosourea compounds.

Apart from other lesions, 51 renal neoplasms were induced in rats by administration of methylethy-, dimethyl- and phenylmethylnitrosourea. 3 tumors originated from the renal pelvis and were classified as transitional cell papilloma (1) or transitional cell carcinoma (2). 48 neoplasms were considered as "mesenchymal tumors". These growths were regarded as rat kidney specific tumors. They display a wide spectrum of histological structures: spindle cells which are capable to differentiate into smooth muscle cells, fibroblasts, angioblasts, fat cells, and even into cartilage thus forming the typical microscopical features which are completed by the tendency of mesenchymal cells to swirl around preexisting renal tubules in several closely investing layers. As the cell of origin is not yet established the term "mesenchymal tumor" seems to be the most suitable one. There is no basis for classifying these tumor as nephroblastomas and the two entities should be strictly separated.

Animals↗

PubMed1978

Methylnitrosophenylurea--a highly carcinogenic compound.

In vitro, 1-methyl-1-nitroso-3-phenylurea (MNPU) was easily formed from 1-methyl-3-phenylurea (MPU) and sodium nitrite in an acid environment. In rats MNPU showed a strong carcinogenic effect, inducing tumors of the forestomach. MNPU was formed endogenously after combined administration of MPU and nitrite to rats, as indicated by the induction of forestomach tumors. MPU itself was not carcinogenic. In the metabolism of the herbicide 1,1-dimethyl-3-phenylurea (fenuron) MPU resulted as a demethylation product. The possible significance for preventive oncology and the role of MNPU as an environmental carcinogen are briefly discussed.

Animals↗

PubMed1977

[The biological behaviour of experimental tumours of the central nervous system (author's transl)].

In 31 experimental groups, 1955 rats were exposed to methyl-, dimethyl-, trimethyl-, and ethylnitrosourea or dimethylphenyltriazene. Altogether, 3102 tumours were registered. 1930 of them were located in the central nervous system. Derived from neurooncological classifications in man, these tumours were subdivided corresponding to a three-step grading scheme. In contrast to brain tumours in man, in rats the degree of dedifferentiation is of minor importance with regard to the clinical course of the cancer disease. In rats CNS tumours lead to death of the animals within a few hours or days after the onset of clinical symptomatology and should be regarded as biologically highly malignant. The grading allows a more exact valuation of the frequency of distinct tumour types in different experimental groups. Following transplacental application, isomorphous neoplasms occur significantly more frequent as compared with anisomorphous ones (grad II and III) which dominate when the carcinogen is given repeatedly to adult animals. Parallels are drawn to human neurooncology.

Animals↗