Biomedical subjects

E L Wiertz-Hoessels

Publications and source records attributed to E L Wiertz-Hoessels.

9 recordsLinked to original sources

PubMed1988

Peptide immunoreactivity in developing entero-endocrine cells in endodermal grafts.

Presumptive endoderm was excised from 19-h chick or quail embryos and grafted, together with a fragment of notochord from a 48-h host chick embryo. After 14 days the graft showed differentiation towards several digestive and respiratory tract structures. Entero-endocrine cells were demonstrated in these structures. Peptide immunoreactivity in these structures was similar to some extent to the peptide spectrum in corresponding regions during normal development, though the number of demonstrable peptides per region under the conditions of grafting appeared to be higher than in control conditions.

Animals↗

PubMed1988

The synthesis of peptides in enteroendocrine cells developing in explanted presumptive endoderm.

Peptide immunoreactivity was studied in grafts of endoderm from chick or quail embryos (19 hours, corresponding to stage 4- to 5 according to Hamburger and Hamilton) in the coelom of a 48 hour host embryo. The presence of gastrin, glucagon, cholecystokinin, VIP, substance P, somatostatin, bombesin, motilin, secretin, pancreatic polypeptide, neurotensin and insulin was demonstrated. The nature of the peptide(s) generally matched the regional differentiation of the enteric epithelium and the underlying mesodermal components. The findings are compatible with the concept of heterogeneity of the endoderm due to migration of epiblast derived cells.

Animals↗

PubMed1987

Differentiation of gut endoderm in dependence of the notochord.

Presumptive intraembryonic endoderm, either isolated or together with adhering mesoderm, from 19-h chick embryos, was grafted to the coelom of 50-h host embryos. The viability of such grafts was low and endodermal differentiation was poor. In a second series the endoderm (with or without adhering mesoderm) was combined with a fragment of notochordal tissue from 48-60-h donor embryos. Then the recovery was much higher, notably after longer periods of in vivo culture. After 10 days of cultivation well-developed entero-endocrine (argyrophilic) cells were found among the regular enterocytes in both series.

Animals↗

PubMed1985

Induction of an additional floor plate in the neural tube.

The role of the notochord in the morphogenesis of the neural tube was investigated by implanting a notochord fragment laterally to the neural wall of a 1.5 day chick embryo. Embryos were sacrificed at 4 days. In the basal part of the neural tube an additional floor plate was induced in the vicinity of the implant. This floor plate was characterized by a low proliferative activity, a thin wall, spindle-like nuclei crowded peripherally and some neuroblast-like cells. It was either blending with the natural floor plate or separated from it, depending on the exact position of the implant. In the latter case neuroblasts were observed in between both floor plates. The additional floor plate was present only when the implanted notochord was less than 25 micron apart from the neural tube; at larger distance an increase of the ventral horn neuroblast area could be seen. It is concluded that the implanted notochord is able to induce a floor plate at 1.5 days of incubation. The specific influence of the notochord on the morphogenesis of the neural tube, its inductive period as well as the presence of the neuroblast-like cells in the additional floor plate are discussed.

Animals↗

PubMed1969