Cellular senescence is a state of irreversible growth arrest. In this paper the authors examined whether bleomycin, an agent that causes pulmonary fibrosis, induces the senescence of alveolar epithelial cells. Type II-like alveolar epithelial (A549) cells or rat primary type II cells were exposed to bleomycin and then evaluated for markers of cellular senescence. Bleomycin was also administered...

An expression system utilizing specialized ribosomes has been constructed with beta-galactosidase as the product. Ribosomes specific for lacZ mRNA are generated due to a mutation within the anti-Shine-Dalgarno region of a plasmidborne 16S rRNA gene that is complementary to a mutation within the ribosome-binding site of lacZ. Hence, a subpopulation of ribsomes specific for translation of the clo...

We have previously reported the discovery of an islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP) that is predominantly expressed in islet beta-cells. IGRP has recently been identified as a major autoantigen in a mouse model of type 1 diabetes. The analysis of IGRP-chloramphenicol acetyltransferase (CAT) fusion gene expression in transiently transfected islet-derived...

Genetic correction of inherited muscle diseases, such as Duchenne muscular dystrophy, will require long term expression of the recombinant protein following gene transfer. We have shown previously that a new adenoviral vector that lacks all viral genes expressed both full-length dystrophin and beta-galactosidase in mdx (dystrophin-deficient) mouse muscle. We observed a significant histologic im...

Objectives: To induce immune tolerance in immune-competent animals with a plasmid (p4F10-eB7) expressing a membranebound single-chain antibody against CTLA4. Materials and Methods: Twenty 9-week old immune-competent C57B/L6 mice were divided into 2 groups. Ten mice received an intramuscular injection of 50 μL of endotoxin-free pCBLacZ plasmid at a concentration of 1 mg/mL in phosphate buffer in...

Escherichia coli B synthesized beta-galactosidase and an enzyme system for D-xylose when exposed to lactose and xylose respectively in nitrogen-free media. The amount of beta-galactosidase formed in the absence of external nitrogen depended upon the nature of the medium in which the cells had originally been grown. Half as much of this enzyme was synthesized without exogenous nitrogen by cells ...

Roles of cell surface carbohydrates containing the 3-fucosyl-N-acetyllactosamine and poly-N-acetyllactosamine sequences (SSEA-1 and I antigens, respectively) in the compaction of mouse embryos have been investigated using the endo-beta-galactosidase of Bacteroides fragilis to modify the surface of cleavage-stage embryos. Treatment with this enzyme abolished SSEA-1 activity and diminished I anti...

The hok/sok locus, isolated from the multiple-resistance plasmid R1 of Escherichia coli, is very efficient at ensuring the stable maintenance of plasmids in Gram-negative systems by killing plasmid-free cells as they arise. To investigate independently the influence of temperature and growth rate on the effectiveness of hok/sok, continuous fermentations have been conducted with the pUC-based, I...