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Biomedical subjects

J Umbreit

Publications and source records attributed to J Umbreit.

6 recordsLinked to original sources
PubMed1989

[Reaction and effectiveness of prednisolone in zinc oxide containing dermatologic agents].

The ions of prednisolone and zinc are reacting in a mole proportion of 2:1, and are forming a defined compound according to the formula ZnL2 (L = prednisolone anion). This was proven by potentiometrical equilibrium investigations. Therefore the application of prednisolone within zinc oxide containing dermatics is less indicated. The limited usability and reduced effectiveness of prednisolone containing zinc oxide-dermatics forbid a central production and storage for a longer time.

Chemical Phenomena↗
PubMed1975

A requirement for reversible binding between aggregating embryonic cells before stable adhesion.

Chick embryonic liver and neural retina cells aggregate in a two-step process. Initially, cells formed a loose association in a step that apparently did not require metabolic energy. Cells bound in this manner were dissociable by mild shear forces or by simple dilution. The results of the dilution experiments suggest a readily reversible binding of single cells to form these types of aggregates. In a second step, which required metabolic energy, the cells became firmly, or stably attached. The formation of both types of bond was temperature-dependent. Kinetic studies indicated that the formation of reversible bonds between cells was required before the cells could become stably attached, and that reversibly bound cells were converted directly into stably bound cells.

Animals↗