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W Liebig

Publications and source records attributed to W Liebig.

6 recordsLinked to original sources
PubMed1977

[Decidualisation of the endometrial stromal cell. An electron microscopic study (author's transl)].

The fine structural changes of the endometrial stromal cell from late secretory phase up to full developed decidua cell have been investigated by means of electron microscope. During decidual transformation the cell volume, the assortment of cytoplasmic organelles and the mode of intercellular attachments undergo characteristic alterations. These alterations reflect an adaptation on new cellular functions. In contrast to the structural organization, which is transformed continuosly, the encymatic cell pattern exerts a step wise gradual transformation, since new encymatic capacities can only arise after their funtional structures have been established. To the most important functions of decidua cells and their prestages belong secretory and endocrine activities. Precollagen fibrills represent a specific secretory product of the stroma reticulum cells. The active involvement of the full differentiated decidua cells in steroid metabolism is indicated by characteristic transformation of the cytoplasmic organization concomittantly to the appearance of intracellular steroid dehydrogenase activities. So-called karyosoma could be demonstrated within the nuclei of postovulatory stromal reticulum cells as in decidua cells. Similar nuclear differentiations have been observed in various target cells of steroid hormones. They possibly are structural manifestations of the hormonal interaction with the nuclear DNA.

Adolescent↗
PubMedDate not supplied

A comparative study of several polymers for use as intravenous catheters.

The widespread use of long-term intravenous catheters has produced some concern on the part of the clinician with respect to morbidity and occasional mortality associated with their use. Fourteen polymer surfaces were evaluated in experimental animals in this study. Several of the materials are commercially available; the others are experimental. In all, 160 catheters were placed in the femoral and jugular veins through side branches. The catheters were evaluated in terms of thrombosis, phlebitis, and periphlebitis, using an arbitary grading system. Scanning electron microscopy and light microscopy were employed to document the results. The most successful catheter materials were next evaluated in man, using the same experimental parameters. It is our belief that the observed thrombosis associated with morbidity is largely due to the surface characteristics of the catheter materials. These characteristics are largely surface phenomena related to the interactions between the tissue and catheter material. In this study, we have attempted to determine whether there are any significant differences in thrombogenicity and/or long-term function between the several currently available catheters. Based on this study, ethylene acrylic acid appears to be the most nonthrombogenic surface of the material tested.

Animals↗