Increase of radiation resistance of a soil microflora exposed to long-term gamma irradiation.

Soil microflora were exposed to long-term (18 months) gamma irradiation in an open-air facility at three different doses, 15, 150, and 1,500 krads/18 months. The radiation resistance increased at all doses when compared with the radiation resistance of the microflora from soil shielded from the irradiation with a lead wall.     

Plasminogen activator inhibitor (type-1) in rat adrenal medulla

Plasminogen activator inhibitor type-1 (PAI-1) was identified in extracts of rat adrenal medulla, and its immunohistochemical localization was studied together with that of tissue-type plasminogen activator (t-PA). By staining of adjacent sections and by double-staining of the same section we demonstrate that the same cells of the adrenal medulla contain both PAI-1 and t-PA immunoreactivity in the cytoplasm. In addition a few ganglion cells of the adrenal medulla were found to contain PAI-1 but not t-PA. Neither of the components were found in the adrenal cortex. Analysis of extracts from isolated adrenal medulla using reverse zymography showed the presence of a plasminogen activator inhibitor with Mr approximately 46,000. The inhibitory activity disappeared when the extract was passed through a column with sepharose-coupled anti-PAI-1 IgG, while the run-through from a similar column coupled with preimmune IgG still contained the inhibitor. The present findings suggest that PAI-1 could play a role in the regulation of t-PA activity in the rat adrenal gland medullary cells.     

Tet-On Induction with Doxycycline after Gene Transfer in Mice: Sweetening of Drinking Water is not a Good Idea

Gene transfer to skeletal muscle leads to long-term, stable expression of transferred genes. An exiting development is the use of inducible expression systems. Using the inducible Tet-On system, it has been customary to administer doxycycline in drinking water with added sucrose to ameliorate the bitter taste. During a study aiming at regulating electrotransferred genes through the Tet-On system, we observed excessive drinking behavior among mice. Removal of sugar from the drinking water led to normal drinking behavior and most importantly did not affect the level of gene expression. Based on this study, the practice of adding sucrose to drinking water in doxycycline induction studies should be abandoned.