Amphibian and mammalian blood was washed in isotonic saline, fixed in glutaraldehyde, and then stained in the ATPase medium of Wachstein and Meisel. The blood cells were subsequently postfixed in osmium tetroxide, embedded in epoxy resins, and studied by electron microscopy. The plasma membranes of amphibian erythrocytes, from the newt Triturus cristatus and the frog Rana esculenta, were staine...

When thiamine pyrophosphate is used as substrate, heavily stained complexly branching cytoplasmic structures are seen in developing oocytes of the hamster between 8 and 12 days after birth. This coincides with the onset of the dictyate stage of first meiotic prophase. The structures appear to arise from the oocyte plasma membrane in two ways: (1) by proliferation and infolding of the membrane, ...

Stem cell-based disease modeling presents unique opportunities for mechanistic elucidation and therapeutic targeting. The stable induction of fate-specific differentiation is an essential prerequisite for stem cell-based strategy. Bone morphogenetic protein 2 (BMP-2) initiates receptor-regulated Smad phosphorylation, leading to the osteogenic differentiation of mesenchymal stromal/stem cells (M...

A reproducible cell culture system is described that allows the study of adipose conversion in fibroblast-like cells isolated by collagenase digestion of epididymal and perirenal adipose tissue from male rats weighing 70-200 g. Adipose conversion as measured by lipid accumulation and increase in glycerophosphate dehydrogenase (GPDH) activity during differentiation strongly depends on the densit...

Acid phosphatase localization in accumulated membranous organelles of optic nerve axons of guinea pigs following acute elevation of intraocular pressure (IOP) was determined, employing light and electron microscopic enzymic cytochemistry with beta-glycerophosphate as a substrate. Positive reaction products appeared to accumulate in the region of the lamina cribrosa, as revealed with light micro...

Brown adipose tissue of the rat has been found to have an unusually high activity of mitohondrial alpha-glycerophosphate dehydrogenase (alpha-GPD) when assayed both by a histochemical staining procedure and by a quantitative biochemical method with isolated mitochondria. In contrast to succinic, glutamic, and beta-hydroxybutyrate dehydrogenases, all mitochondrial enzymes, the activity of alpha-...

1. A phosphodiesterase that cleaves glycerophosphoinositol into glycerophosphate and inositol has been detected in rat tissues. 2. The enzyme requires Mg2+(Mn2+) and has a pH optimum of 7.7. 3. The richest sources of the enzyme are kidney and intestinal mucosa. In pancreas subcellular fractions it occurs largely in the microsomal fraction. 4. The enzyme is inhibited by excess substrate and by t...

An antigen composed of glycerophosphate and glucose has been isolated from the cell walls of a strain of Staphylococcus albus. The antigen reacted with homologous and heterologous S. albus antisera. Similar material was isolated from the cell walls of three other S. albus strains. The antigen did not react with S. aureus antiserum nor with normal human or rabbit serum. The antigen appeared to h...

A membrane-bound, monovalent cation-stimulated ATPase from Zea mays roots has been purified to a single band on sodium dodecyl sulfate gel electrophoresis. Microsomal preparations with K(+) -stimulated ATPase activity were extracted with 1 m NaClO(4), and the solubilized enzyme was purified by chromatography on columns of n-hexyl-Sepharose, DEAE-cellulose, and Sephadex G-100 Superfine. A 500-fo...