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Biomedical subjects

D Septier

Publications and source records attributed to D Septier.

79 records · Page 5Linked to original sources
PubMed1981

Microchannels in the surface zone of artificially produced caries-like enamel lesions.

In the surfaces zones of artificial carious lesions, tiny microchannels, about 0.5 - 1.5 micrometers in diameter and roughly 100 micrometers in length, have been observed. The mineral components seem to be concentrated at the lumen borders, whereas the organic components have disappeared or are disorganized. These observations suggest that the channels mentioned are involved in the lesion development and play an important role in diffusion (transport) processes taking place between the sub-surface lesion and the liquid phase outside the lesion. The microchannels originate in prisms in the perikymata of the surface enamel. They extend in the direction of the Hunter-Schreger bands, mainly in connection with diazones. No relationship could be found between the microchannels and the direction of the prism sheaths. This indicates that in initial artificial lesion formation the enamel structure plays an important role.

Dental Caries↗
PubMed1980

[Role of secretion in the dynamics of the maturation of predentin. Morphological, autoradiographic and freeze fracture study in the rat; changes induced by vinblastine].

Morphological and autoradiographic data give evidence that secretion take place at the odontoblast process level according to a lateral axis, perpendicular to the maturation axis of the predentine. Induced modifications with vinblastine sulphate emphasize the importance of the pericellular space (150--200 nm) while the disorganization of the collagen fiber arrangement suggests the presence of flows. We propose an hypothesis which connects all these facts.

Animals↗
PubMed1980

[Effect of 2 methods of demineralization on the on the preservation of glycoproteins and proteoglycans in the intertubular and peritubular dentin in the horse].

The effect of 2 methods of demineralization on the preservation of proteoglycans and glycoproteins was studied in the intertubular and peritubular dentine of the horse. The specimens embedded in Epon were demineralized with a 2% acid formic solution (Bonucci and Gheradi, 1975). Other fragments were treated with an organic solution of EDTA alkylammonium salt (Scott and Kyffin, 1979). These methods preserved in a satisfactory way these labile organic components. In the intertubular dentine, glycoproteins and proteoglycans were also identified, either associated with collagen fibres as a glue and granules, or present in the interfibrillar spaces. In the peritubular dentine, amorphous material formed a fine network between the mineral structures.

Animals↗
PubMed1979

[Autoradiographic study of the activity of odontoblasts and secretory ameloblasts in the rat incisor: changes induced by vinblastine].

An autoradiographic study conducted on the rat incisor showed the presence 4 hours after (3H) proline injection, of 25-30% of the grains on the secreting cells and 70 to 75% on the extracellular matrics. The simultaneous injection of vinblastine sulphate reversed these percentages to 75-80% on the cellular level and 25-25% on the matrics. The vinblastine therefore inhibited the secretory processes of these cell types. On the other hand, due to the alkaloid, the number of grains present increased over the ameloblasts and principally over the intercellular spaces. The effects of these secretion and permeability variations suggested that a flow of precursor rich material reached the epithelial layer whatever the state of ameloblast activity.

Ameloblasts↗
PubMedDate not supplied

Apoptosis in human and rat dental pulp.

Apoptotic cells were visualized in human premolar and rat molar pulps using either the TUNEL method, which stains DNA strand breaks by in situ nick end labeling, or labeling sections with an anti-transglutaminase antibody. Apoptotic cells were evident at the periphery of the pulp, mostly in a sub-odontoblastic location, and were more numerous in the crown than in the root region of the pulp. Most odontoblasts were unlabeled. A few apoptotic nuclei in the pulp of rat molars displayed the characteristics of chromatin condensation, as observed by electron microscopy. Many cell debris resembling apoptotic bodies were also observed. The 3 methods support the occurrence of apoptosis in the dental pulp. As this phenomenon was observed in healthy teeth apoptosis is probably involved in the regulation of the pulp cell population.

Animals↗