Detection of Neisseria gonorrhoeae by ultraviolet illumination of NADH generated by an immobilized antibody-gonococcal enzyme complex.

Frozen, cervical swabs were placed in a lysis buffer containing an immobilized antibody to the gonococcal enzyme, 1,2-propanediol oxidoreductase. The immobilized antibody--enzyme complex that formed was active after the addition of substrate (1,2-propanediol and NAD) and this activity could be detected by visual inspection of NADH fluorescence under ultraviolet illumination.

Enhancement of plasma alpha-fetoprotein, as measured by sandwich-type radioimmunoassay, and induction of gamma-glutamyl transpeptidase-positive hepatic cell foci in rats fed benzo[a]pyrene.

Male Fischer rats were fed semipurified diets containing 0, 1, 100, and 1000 ppm benzo[a]pyrene (BaP) for 6 or 13 wk. Plasma samples were assayed for alpha-fetoprotein (AFP) by a new sandwich-type radioimmunoassay (RIA) utilizing a special controlled porous-glass solid phase. This procedure is described in detail. Significant AFP elevation (p less than or equal to 0.01) was observed in the highest BaP treatment group after 5 wk of treatment. The 1 and 100 ppm Bap groups exhibited no AFP elevation throughout the study. Liver sections from the 1000 ppm groups had discrete gamma-glutamyl transpeptidase (GGT)-positive foci 10-20 cells in diameter by the 6th wk. GGT-positive foci were not evident in liver sections from the other treatment groups. Thus a high level of dietary BaP appears to rapidly alter rat liver cells, indicating hepatic neoplasia.

The isolation and characterization of a 1,2-propanediol oxidoreductase from Neisseria gonorrhoeae.

An enzyme which oxidizes 1,2-propanediol in the presence of NAD+ has been purified from lysates of Neisseria gonorrhoeae. The enzyme was activated by monovalent cations, had a pH optimum between 9 and 10, and showed a substrate specificity unlike any known alcohol or glycerol dehydrogenase. The enzyme had an apparent Km of 17 mM for 1,2-propanediol and 0 . 37 mM for NAD+. When chromatographed on a Sephadex G-150 column, the enzyme eluted as a single peak in the molecular weight region of a bovine serum albumin marker. An antibody to the purified enzyme was prepared in goats. When antiserum was reacted with the enzyme in immunodiffusion experiments, a single precipitin band was detected. When the enzyme was mixed with an excess of antibody and then reacted with substrate, enzyme activity was completely inhibited.

Measurement of serum free thyroxine by RIA in various clinical states.

A radioimmunoassay for quantitatively measuring the serum concentration of free thyroxine is described. This method does not require equilibrium dialysis, and is rapid and reproducible. The serum values obtained by this radioimmunoassay and by equilibrium dialysis are similar in normal subjects, hyperthyroid and hypothyroid patients, pregnant women, "sick euthyroid" patients, and euthyroid patients with hereditary TBG abnormalities. The method also provides a total serum thyroxine concentration in the same assay procedure.

Solid phase radioimmunoassays (SPRIA) using antibodies covalently bound to controlled pore glass (CPG).

Covalent coupling of antibody molecules has found broad application in the area of radioimmunoassay (RIA). A complete set of convenient thyroid assays has been developed employing both conventional and some new RIA techniques. These assays offer the clinician rapid and precise data quickly so that appropriate diagnosis can be speedily accomplished. Some of the techniques presented could only have been done with this technology. Details of assays for T4, T3, TBG, TSH, and FT4 are presented in this paper.