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Biomedical subjects

J L WHITBY

Publications and source records attributed to J L WHITBY.

At least 19 recordsLinked to original sources
PubMed1964

PSEUDOMONAS PYOCYANEA AND THE ARGININE DIHYDROLASE SYSTEM.

Non-pigmented strains of Pseudomonas pyocyanea occur frequently and this organism has only limited activity in conventional biochemical tests; 50 strains were tested for the presence of arginine dihydrolase and found positive whereas only Salmonella sp. and Enterobacter sp. among other Gram-negative species were positive. The test for arginine dihydrolase is rapid and simple and suitable for routine use.

Arginase↗
PubMed1962

Studies on natural antibodies to gram-negative bacteria.

A study was made of the origin, occurrence, and properties of natural antibodies to Gram-negative bacteria in the normal serum of several species. Antibody was measured by a procedure based on the bactericidal reaction carried out under conditions in which activity was a function of the amount of antibody contributed by the test serum. Antibody to seven genera of the family Enterobacteriaceae were demonstrated in normal human serum. The specificity of these antibodies was affirmed by absorption with homologous bacteria and by inhibition of bactericidal activity with purified homologous somatic antigen. Absorption with graded amounts of bacterial suspensions showed that a large excess of bacteria led to non-specific removal of antibodies. Analogous findings were also made with immune antibody. As determined by quantitative absorption tests no difference could be found in the avidity of natural and immune antibody. Natural antibody in the serum of various species differed considerably as regards their lability to heat, but in parallel tests immune antibody of each species was significantly more heat-stable. The time and appearance of the antibodies varied in young animals, of different species. Mice developed these antibodies at the earliest age, with guinea pigs, rats, and rabbits following in that order. Serum from germ-free rats and chickens had no demonstrable antibodies to E. coli or S. typhosa whereas these antibodies were present in the serum of litter mates reared under conventional conditions. On the other hand germ-free and conventional mice did not differ appreciably as regards the levels of these same antibodies.

Animals↗
PubMed1962

Bactericidal method for the measurement in normal serum of antibody to gramnegative bacteria.

Landy, Maurice (National Cancer Institute, Bethesda, Md.), J. Gabriel Michael, and James L. Whitby. Bactericidal method for the measurement in normal serum of antibody to gram-negative bacteria. J. Bacteriol. 83:631-640. 1962.-The bactericidal effect of normal serum on gram-negative bacteria was investigated with the objective of determining whether this antibody-complement reaction could be used for the measurement of antibody. The major variables affecting the outcome of this complement-dependent reaction were explored systematically to establish the test conditions in which specific antibody was the limiting factor. Among these were the use of an excess of absorbed human serum as a complement source, inoculum, reaction conditions, and precise enumeration of surviving bacteria. It was demonstrated that the test conditions could be controlled so as to provide a sensitive and objective assay for antibody to representative strains of various gram-negative genera.

Anti-Bacterial Agents↗