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Biomedical subjects

R Witkus

Publications and source records attributed to R Witkus.

7 recordsLinked to original sources
PubMed1992

Yeast biology.

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Saccharomyces cerevisiae↗
PubMed1989

Cell surface changes during electromagnetic field exposure.

Fibroblasts from 5 1/2-day-old chick embryos go through a sequential series of changes when exposed to a constant electromagnetic field (EMF) of 10 V/cm. These changes include rounding up, becoming bipolar in shape, assuming a cylindrical profile, elongating perpendicular to the EMF, and migrating to the cathode. These morphological changes are associated with changes of the cell surface, which include the formation of filopodia and extensive sheet-like contacts on the cathodic cell surface, the retraction of processes and the formation of focal contacts on the anodic cell surface.

Animals↗
PubMed1982

An unusual arrangement of smooth membranes in the root meristem cells of Allium cepa L. following exposure to colchicine.

The unusual membranes in the root meristem cells of Allium cepa after exposure to colchicine are arranged in a closed multilayered structure consisting of a pair of double unit membranes enclosing a ground substance which consists essentially of ribosomes. The spaces between the unit membranes and between the pairs of unit membranes are uniform throughout the entire organelle. There is some indication of the association of this organelle with mitochondria.

Colchicine↗
PubMed1982

Function-related structural characters and their modifications in the hindgut epithelium of two terrestrial isopods, Armadillidium vulgare and Oniscus asellus.

Intercellular junctions of the hindgut epithelial cells of two terrestrial isopods, Armadillidium vulgare and Oniscus asellus, are described. Long septate desmosomes occupy the subluminal region while gap junctions, zonulae adherens and intercellular spaces characterize the remainder of the convoluted lateral cell borders. The specialized junctional complexes and the ultrastructural morphology of the cells indicate that the terrestrial isopod hindgut epithelium functions in transport. Using mitochondrial morphometry as an indicator of cell transport activity, it appears that the posterior hindgut of A. vulgare also participates in osmoregulation, which is not the case with O. asellus. With increased desiccation there develops a significant difference between the mitochondrial structure of the two species. The mitochondria of the former retain the active structural condition (intermediate condensed conformation) while those of the latter become swollen and damaged.

Animals↗