Precancerous morphologic and functional aberrations in the rat mammary glands carcinogenesis.

The precancerous changes of mammary glands in 7,12-dimethylbenz(alpha)anthracene (DMBA) induced carcinogenesis in Wistar rats were examined. Carcinogen was inserted into the left fifth mammary gland of the anesthetised rats. After 35 days all the animals were sacrificed and mammary glands were extirpated. Macroscopic examination of mammary glands was performed and the tissue was processed for a pathohistological analysis. H&E, VanGieson's and Toluidine-blue methods were applied, as well as ABC immunohistochemical method with anti-cytokeratin antibodies.The identified precancerous changes resembled to aberrations of fibrocystic disease in women. The fibrosclerosis, lobular hyperplasia, cystic ductal dilatation and apocrine metaplasia of ductal epithelium were found. Micropapillomatoid hyperplasia was another frequent finding, but the presence of the real papilloma was not registered. The keratocysts with the squamous epithelial metaplasia were present in three of the animals. Dysplastic changes were found in the skin, above the treated glands. The difference in expression of cytokeratins, between normal and preneoplastic epithelium, makes cytokeratin useful for verification of early precancerous lesions. The epithelial ductus and ductulus cells of the mammary glands of animals belonging to the control group showed neither CK 19 nor CK 14 expression.

Apatite formation on nanomaterial calcium phosphate/poly-DL-lactide-co-glycolide in simulated body fluid.

UNLABELLED: Simulated body fluid (SBF) is an artificial fluid which has ionic composition and ionic concentration similar to human blood plasma. PURPOSE: This paper compares the interaction between the nanomaterial containing calcium phosphate/poly-dl-lactide-co-glycolide (N-CP/PLGA) and SBF, in order to investigate whether and to what extent inorganic ionic composition of human blood plasma leads to the aforementioned changes in the material. METHODS: N-CP/PLGA was incubated for 1, 2, 3, and 5 weeks in SBF. The surface of the material was analyzed on SEM-EDS and FTIR spectrometer, while SBF was subjected to pH and electrical conductivity measurement. RESULTS: Our results indicate that dissolution of the polymer component of the material N-CP/PLGA and precipitation of the material similar to hydroxyapatite on its surface are based on the morphologic changes seen in this material. CONCLUSIONS: The mechanism of the apatite formation on the bioceramic surface was intensively studied and was considered crucial in designing the new biomaterials. The results obtained in this work indicate that N-CP/PLGA may be a good candidate for application to bone regeneration.