Electron-microscopic studies on the effect of calcium pantothenate upon rat liver and locally irradiated epidermis

Calcium pantothenate was administered to Wistar rats in a dose of 180 mg/day/rat for 42 days, in order to investigate its effect upon the ultrastructure of the epidermis locally irradiated with a dose of 600 rep and upon partly hepatectomized liver and locally irradiated epidermis, as compared to control. The resulting data have revealed that calcium pantothenate is metabolized without entailing ultrastructural changes. Both liver and epidermis appear to be protected by calcium pantothenate, which greatly diminishes or even cancels the display of irradiation-induced negative effects. The changes brought about by irradiation are throughly presented and the subcellular mechanisms providing the radioprotection of epidermis and liver are accurately defined.

The effect of atmospheric pollution on Vitis vinifera L. pollen ultrastructure under natural conditions

The ultrastructural modification of pollen grains in Vitis vinifera L. variety and hybrids in areas of SO2 atmospheric pollution (the main polluting SO2 usually reaches 2.72 mg/m3), nitrogen oxide, and other gases derived from noniron metal processing factories have been studied. Strains 1001 and 1002, resistant varieties, do not undergo ultrastructural modifications. Neuburger and Issabelle, medium resistant ones, have a heterogeneity in ultrastructural organization from normal forms to forms having both wall covers as well as the main organelles changed.

Diabetic lymphangiopathy. An optical and electron microscopic study

The lymphatic capillaries in the tegument of the dorsal side of the leg in patients with diabetes mellitus, and especially in those with clinically manifested macroangiopathy, present morphopathological modifications at the level of the endothelium and the basal membrane. Ultrastructurally, the modifications appear as dilatations of the intercellular space, dislocation or desquamation of the endothelium, an exaggerated growth of the micropinocytic vesicles, the appearance of the intracellular vacuoles and of the lysosomes. These modifications point to an increase in the endothelium permeability, which is an important phenomenon in the diabetic microangiopathy.

Subcellular distribution of calcium within root meristem cells

The barley root (Hordeum vulgare) of 3-day old seedlings were treated with potassium oxalate to study the distribution of calcium among plant cell organelles. The best results were obtained by previously treating the root with 10(-3) M CaCl2 followed by an incubation for 20 min with potassium oxalate. The unstained sections for electronmicroscopy showed the deposits of calcium oxalate as a granular or a dark layer on the mitochondria, endoplasmic reticulum and the nucleare envelope. Within all the cells, dark bodies, like vacuoles, were noticed.