The fine structure of mitochondria and mitochondrial nucleoids in exponentially growing Physarum polycephulum was studied at various periods throughout the mitochondrial division cycle by light and electron microscopy. The mitochondrial nucleoid elongates longitudinally while the mitochondrion increases in size. When the nucleoid reaches a length of approximately 1.5 ~m the mitochondrial membra...

Cartilage has poor regenerative capacity. Donor site morbidity and interference with joint homeostasis should be considered when applying the autologous chondrocyte transplantation technique. The use of ectopically produced cartilage, derived from periosteum, might be a novel method to heal cartilage defects. Ectopic cartilage was produced by dissecting a piece of periosteum from the tibia of r...

1. Nitrogenase activity of a strain of Azotobacter chroococcum lacking the structural genes for conventional nitrogenase (nifHDK) was separated into two components: an Fe-containing protein and a vanadoprotein. 2. The larger protein was purified to homogeneity by the criterion of electrophoresis of 10% (w/v) acrylamide gels in the presence of SDS. Two types of subunit, of Mr 50,000 and 55,000, ...

Methionine dependence is a metabolic defect that occurs in many hu man tumor cell lines but not normal in unestablished cell strains. Mrthionine-dependent tumor cell lines are unable to proliferate and arrest in the late S/(,, phase of the cell cycle when methionine is replaced by its immediate precursor homocysteine in the culture medium (\1ET~HCY* medium). However, it is not known whether met...

Methionine dependence is a metabolic defect that occurs in many hu man tumor cell lines but not normal in unestablished cell strains. Mrthionine-dependent tumor cell lines are unable to proliferate and arrest in the late S/(,, phase of the cell cycle when methionine is replaced by its immediate precursor homocysteine in the culture medium (\1ET~HCY* medium). However, it is not known whether met...

The majority of pre-clinical studies of hypoxic-ischemic encephalopathy at term-equivalent have focused on either relatively mild insults, or on functional paradigms of cerebral ischemia or hypoxia-ischemia/hypotension. There is surprisingly little information on the responses to single, severe 'physiological' insults. In this study we examined the evolution and pattern of neural injury after p...

Hydrogen peroxide (H2O2) plays a pivotal role in various industrial applications [1]. It is an essential mediator in pharmaceutical, clinical, and environmental research. In addition, it is a byproduct of highly selective oxidases and an important contaminant in several industrial products and wastes [2]. Therefore, a reliable and economical method for the determination of H2O2 is of great sign...

The effect of a specifically adsorbed ion, phosphate, on the electrochemical response and adsorption properties of nanocrystalline TiO2 is examined. Phosphate is known to affect the ú potential, as measured by electrophoretic mobility, by changing the charge of the oxide surface. The adsorption of a cationic probe molecule, thionine, onto TiO2 was monitored with an in-situ cell using UV-vis spe...