Chromatography and electrophoresis techniques for demonstrating the presence of cellular N6-(delta2-isopentenyl)-adenosine-3''-monophosphate

Bacteriophage T4 gene 32 encodes a DNA unwinding protein required for DNA replication, repair, and recombination. Gene 32 temperature-sensitive mutations enhance virtually all base pair substitution mutation rates.     

Treponema denticola as a model for polar adhesion and cytopathogenicity of spirochetes

Recent studies suggest that the tip-oriented adhesion of Treponema denticola is a consequence of polar clustering of its adhesins on contact with the substratum and is compatible with viability. Such adhesion to cells stimulates a host of cytoskeletal and volume regulatory changes. These studies may give insight into mechanisms of colonization and cytopathogenicity of other pathogenic spirochetes.     

Heparin attenuates bleomycin but not silica-induced pulmonary fibrosis in mice: possible relationship with involvement of myofibroblasts in bleomycin, and fibroblasts in silica-induced fibrosis

The metal alloys which were investigated histopathologically in the first part of this study, were examined with respect to their allergic potentials using the patch test. Results from 60 subjects (aged 17-23) were evaluated following exposure to nickel sulphate, potassium dichromate, silver nitrate, cobalt nitrate, copper sulphate, palladium chloride, platinum chloride and gold chloride. Nickel sulphate produced the most vigorous allergic response whereas gold chloride showed the least of all. The remaining solutions were ranked in decreasing order of severity as follows: potassium dichromate, cobalt nitrate, silver nitrate, copper sulphate, palladium chloride and platinum chloride. Patch testing is indicated in any patient with a history of allergy or sensitivity to a metal. The use of nickel containing alloys in such patients should also be avoided.     

Expression and characterization of the catalytic core of tryptophan hydroxylase

Wild type rabbit tryptophan hydroxylase (TRH) and two truncated mutant proteins have been expressed in Escherichia coli. The wild type protein was only expressed at low levels, whereas the mutant protein lacking the 101 amino-terminal regulatory domain was predominantly found in inclusion bodies. The protein that also lacked the carboxyl-terminal 28 amino acids, TRH102-416, was expressed as 30% of total cell protein. Analytical ultracentrifugation showed that TRH102-416 was predominantly a monomer in solution. The enzyme exhibited an absolute requirement for iron (ferrous or ferric) for activity and did not turn over in the presence of cobalt or copper. With either phenylalanine or tryptophan as substrate, stoichiometric formation of the 4a-hydroxypterin was found. Steady state kinetic parameters were determined with both of these amino acids using both tetrahydrobiopterin and 6-methyltetrahydropterin.