Synthesis of satellite DNA in wounded plants.
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Autoradiography↗
Biomedical subjects
D Broekaert
Publications and source records attributed to D Broekaert.
Keratin pattern in hyperkeratotic and ulcerated gastric pars oesophagea in pigs.
Ulceration of the gastric pars oesophagea is a serious problem in the pig industry, and in spite of numerous studies the underlying mechanisms of the development of such ulcers remains largely unknown. The present study was designed first to test the hypothesis that the epithelium of the pars oesophagea of affected pigs would be more susceptible to the irritating action of acidic gastric content owing to a change in the pattern of expression of keratin, and second to look for a member of the keratin family that could be a suitable indicator of early lesions. Samples were collected from the gastric pars oesophagea of slaughter pigs with and without grossly visible mucosal changes, and the keratin patterns of normal and hyperkeratotic and ulcerated epithelium were compared immunohistochemically. The keratin pairs K 4/K 13, and K 5/K 14 were present in both normal and affected epithelia, and had a similar pattern of expression in both conditions. K 4 and K 13 were expressed in all the suprabasal layers, and K 5 and K 14 were expressed only in the basal and epibasal cells. Immunological reactivity with the monoclonal antibodies LL020 and LHK6-markers for hyperproliferative conditions-was present in the suprabasal layers of the epithelium of the hyperkeratotic and the ulcerated pars oesophagea but not in the normal epithelium. These results indicate that K 6 is expressed in association with the mucosal changes. The pattern of the intermediate filaments of keratin suggests that in basic to gastric ulcers in pigs there is an epithelial proliferation leading to visible hyperkeratosis.
Animals↗
Further research on solubilization of cholesteatoma keratins.
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Amino Acids, Sulfur↗
Differentiation of nuclei during keratinization in middle ear cholesteatoma. DNA cytophotometry completed by computerized image analysis.
Quantitative DNA cytophotometric techniques were applied to judge the alteration (differentiation) and ultimate fate of nuclei during keratinization in human middle ear cholesteatoma. Compared with a healthy epidermis, a tendency towards postponed nuclear degradation was noticed. Two patterns governing the loss of DNA are recognized. In one group, the mean nuclear DNA content declines continuously, starting in the nearest suprabasal layers and continuing throughout the prickle and granular cell stages, where the ultimate degeneration of nuclei takes place. This pathway corresponds to that observed in epidermis, but evolves more slowly. In another group of samples, the onset of the DNA decline is delayed to the upper prickle cells, exceptionally to more terminal stages of keratinization. During matrix keratinization, a profound nuclear remodelling takes place, similar to that in epidermal tissues, as far as eu- and heterchromatin DNA and area data are concerned. However, euchromatinization of nuclei in matrix prickle cells is more pronounced than in epidermal tissues. The topography of residual heterochromatic clumps does not reflect a persistent margination as in epidermal nuclei, but is the result of more individualized rearrangements. The changes in karyotype are less elaborate when the complete decline of the nuclear DNA content only occurs during terminal keratinization.
Cell Nucleus↗