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R V Rechenmann

Publications and source records attributed to R V Rechenmann.

10 recordsLinked to original sources
PubMed1981

Influence of meningeal cells on the proliferation of neuroblasts in culture.

The influence of meningeal cells and meningeal extract derived from surrounding mesodermal membranes from chick embryo brains on the proliferation of neuroblasts was studied. In basal nutrient medium, the neuroblasts formed small clusters, while in the presence of meningeal cells and meningeal extracts large cellular clumps were observed. The proliferative activity of the neuroblasts in the aggregates was confirmed by autoradiographic experiments after [3H]-thymidine incorporation. The contact with meningeal cells produced a higher stimulatory effect on neuronal cells from 5- and 6-day-old embryos, while meningeal extract was more active on neuroblasts from 3- and 4-day-old embryos. The neuroblasts from 7-day-old embryos were stimulated neither by meningeal cells nor by the extract.

Animals↗
PubMed1977

Nuclear, nucleolar repair, or turnover of DNA in adult rat brain.

Labeled thymidine administered to adult rats is incorporated at a low level into brain DNA as shown by biochemical and autoradiographic methods. This incorporation takes place in part into neuronal nuclei and nucleoli and also into glial nuclei. While incorporation into glial nuclei is interpreted to represent known glial cell proliferation, incorporation into neuronal nucleoli may be related to nucleolar DNA synthesis, which in turn is responsible for the regulation of nucleolar RNA synthesis. It could also be due to DNA repair synthesis. Assuming this latter phenomenon, our results suggest that nucleolar DNA is more sensitive than chromosomal DNA to ionizing radiations and other factors.

Animals↗
PubMedDate not supplied

Sulfated polysaccharides modulate effects of acidic and basic fibroblast growth factors on repair of injured confluent human vascular endothelium.

Semi-automatic analysis of the repair process of a circular mechanical lesion of confluent human vascular endothelial cells in vitro was used to evaluate the contributions of cell migration and cell proliferation. Standard heparin added to culture medium that contained 30% human serum induced an inhibition of cell migration at the lesion margin during the first day after injury. Several sulfated polysaccharides were tested in the presence of 5% human serum. Standard heparin, low molecular weight heparin, or pentosan polysulfate markedly reduced the rate of lesion regeneration. Cell proliferation, measured by 3H-thymidine incorporation at the lesion margin, and cell migration were both decreased. In contrast, the combination of acidic fibroblast growth factor with a sulfated polysaccharide accelerated the repair process. Basic fibroblast growth factor combined with a sulfated polysaccharide gave a regeneration rate similar to that of the control; however, at 4 days after injury, the residual lesion was the same when basic fibroblast growth factor was used alone or when it was combined with sulfated polysaccharides. Acidic fibroblast growth factor totally reversed the effects of sulfated polysaccharides on the repair process by enhancing endothelial cell proliferation and allowing endothelial cell migration.

Autoradiography↗