Biomedical subjects

P C van der Vyver

Publications and source records attributed to P C van der Vyver.

3 recordsLinked to original sources

PubMed1984

Abnormal keratohyalin-like forms in leukoedema.

Electron microscopic, histochemical and light-microscopic studies were carried out on biopsy specimens of 12 cases of leukoedema and on the desquamated epithelial cells of a further 50 examples. For comparison, similar observations were made of 4 examples of healthy cheek mucosa and 29 cases of a variety of pathological conditions of the oral mucosa. Only in leukoedema were a series of structures encountered which consisted of an aggregation of ribosomes and electron dense masses, or a network of electron-dense material, or an electron-dense network with a central dense core or a solid body with a few central cavities. Histochemical stains and RNA extraction studies showed that they are probably abnormal forms of keratohyalin granules and that ribosomes is an important component of their composition.

Cytoplasmic Granules↗

PubMed1983

Ameloblastic fibroma with dentinoid formation/immature dentinoma. A microscopic and ultrastructural study of the epithelial-connective tissue interface.

The epithelial-connective tissue interface in an ameloblastic fibroma with dentinoid formation shows four characteristic features: epithelium which is surrounded by a cellular stroma, by a cell-free zone, by a cell-free zone consisting of an amorphous hyaline-like material, and by a dentinoid material. The ultrastructure of these four characteristics resembles stages of the developing tooth. The cellular epithelial-connective tissue interface corresponds to early development before the "bud cap" stage described by Sisca and Provenza (1972). The cell-free zone resembles the "bud cap" stage, and the amorphous layer the "intermediate bell" stage, whereas the interface with dentinoid material has all the features of the "late bell" stage, except for the absence of calcification.

Child↗

PubMed1983

Cytoplasmic granules in exfoliated buccal epithelial cells.

The cytoplasmic granules in exfoliated epithelial cells of healthy cheek mucosae of seven subjects were studied by means of phase-contrast microscopy, electron microscopy and histochemistry. An electron microscopic technique was used to study specific granules which had been identified with the light microscope. Phase-contrast microscopy revealed that the cytoplasmic granules are present in unfixed material. Ultrastructurally they consist mostly of discrete, dense granular bodies. Also seen were collections of electron-dense masses, collections of organelles and organelles mixed with granular bodies and electron-dense masses. Histochemically they stain like keratohyalin. No lipids were detected. We propose that the discrete bodies are normal keratohyalin granules and the electron-dense masses are granules in stages of disintegration. When the granules break down they become mixed with organelles. The keratohyalin granules are the darkly-stained granules seen microscopically, and the disintegrating granules and collections of organelles the weakly-stained, indistinct cytoplasmic granules.

Adult↗