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Biomedical subjects

R P Nuttall

Publications and source records attributed to R P Nuttall.

6 recordsLinked to original sources
PubMed1976

Epithelial stratification in the developing chick cornea.

The process of epithelial stratification was studied in the embryonic chick corneal eipthelium between 10 and 21 days of incubation. Information was collected on the DNA synthetic activity occurring in individual cell layers, on cell density changes in the basal layer, and on mitotic spindle orientation in each cell layer before, during, and upon the completion of alyer formation. Prior to the initiation of stratification, mitotic spindles are oriented parallel to the basement membrane interface. This orientation changes to predominantly vertically directed spindles as layer formation proceeds. Later, the majority of the spindles are horizontally aligned once more. This pattern was observed as each successive cell layer formed. The possible relationship between the spindle data and that obtained on DNA synthetic activity and cell density changes is discussed in terms of the role these factors might play in layer formation in the cornea, as well as in other stratified epithelia.

Animals↗
PubMed1976

DNA synthesis during the development of the chick cornea.

The frequency and pattern of DNA synthesis were analysed autoradiographically in the developing chick cornea. Each cellular population was studied in time-sequence fashion from the time of its appearance until hatching. There is a sharp drop in the synthetic index (number of labeled cells/total number of cells) in the anterior corneal epithelium soon after its formation, corresponding in time to the secretion of extracellular matrix material by this tissue. A similar decrease does not occur in adjacent tissues. Continous labeling experiments show that about 20% of the corneal cells are not in the proliferative pool at this time while 100% of the cells in the underlying lens epithelium and the surrounding head epidermis and head mesenchyme are labeled. Cell cycle measurements indicate that the proliferative kinetics of both the corneal epithelium and the head epidermis are similar at this time even though the percentage of labeled cells in each region differs. The formation of the corneal endothelium and the movement of fibroblasts into the stromal region are events which involve extensive cellular migration. Labeled cells are observed at all stages of both endothelial and stromal fibroblast migration, indicating that DNA synthesis occurs during the course of cellular migration in the developing cornea.

Animals↗
PubMed1976

Differential labeling of the cell surface of single ciliary ganglion neurons in vitro.

Cationic ferritin binds in a time and concentration dependent manner to all surfaces of ciliary ganglion neurons in culture except "mounds" and "veils". In chase experiments, bound ferritin clears from the cells surfaces and forms larger and larger patches, even at low temperatures. Binding of cationic ferritin is inhibited by poly-L-lysine, potentiated by poly-L-glutamate, and not affected by neruaminidase (acylneuraminyl hydrolase, EC 3.2.1.18), hyaluronidase (hyaluronoglucosidase, hyaluronate 4-glycanhydrolase, EC 3.2.1.35), or chondroitin ABC lyase (EC 4.2.2.4).

Ammonium Chloride↗