Organophosphonate Utilization by the Wild-Type Strain of Penicillium notatum

We studied the biodegradation of compounds containing phosphorus-to-carbon bonds by using a wild-type strain of Penicillium notatum. The substrate specificity of this strain was studied, and we found that it is able to utilize structurally diverse organophosphonates as sole sources of phosphorus. This ability seems to be inducible, as indicated by the presence of a lag phase during growth. A popular herbicide, glyphosate, inhibited fungal growth, but it was also degraded by the fungus if it was applied in sublethal doses. This indicates that P. notatum may play an important role in biodegradation of organophosphonates. The strain which we used did not metabolize any of the phosphonates which we tested when they were used as sole carbon or nitrogen sources.     

Molecular mechanism of the juvenile hormone action.

Structures, physiological role and level regulation of the juvenile hormones are described. A scheme of juvenile hormone mode of action at the molecular level, which includes transport of hormone via its binding protein, is presented.     

An Autoradiographic Study of the Developing Parietal Cell Population In Neonatal Pigs

Abstract. Autoradiographic labelling using tritiated thymidine ([³H]TdR) was used to examine the pattern of development of gastric parietal cells in newborn pigs. Specific objectives were to establish sites in the gland where cells with a characteristic parietal cell morphology first appear, the extent of their migration or displacement, and the kinetics of any development and migration that occurs. Five newly-born littermate piglets were given a virtually continuous label of [³H]TdR over 24 hr, sacrificed at 1, 3, 5, 7 and 10 days thereafter, and samples of the gastric mucosa taken. the percentage of labelled parietal cells as a function of position in the oxyntic gland was measured for each pig. A generalized log linear model was fitted to the data using the statistical package GLIM, confirming a significant trend for labelled cells to occupy higher sites in the oxyntic gland as the time since labelling of cells increased. Goodness of fit tests showed that the trend effect was highly unlikely to be due to the variability of cell distribution from animal to animal. the dynamics of the parietal cell population and the strengths of GLIM for analysing cell labelling data are discussed.