Rabbit antibody detection with RNA aptamers

Antibody-based detection systems are widely used, but in the cases of immunoprecipitations and enzyme-linked immunoassays, they can be laborious. These techniques require the preparation of at least two kinds of non-cross-reactive immunoglobulin Gs (IgGs), usually made from different species against the single target molecule. Aptamers composed of nucleic acids possess strict recognition ability for the target molecule's three-dimensional structure and, thus, are considered to act like IgG. In this study, experimental trials were designed to combine the advantages of IgG and aptamers. For this purpose, aptamers against rabbit IgG were identified by in vitro selection. One of the obtained aptamers had a dissociation constant lower than 15 pM to the rabbit IgG. It bound specifically to the constant region of the rabbit IgG, and no binding was observed with mouse or goat IgG. Moreover, this aptamer recognized only the native form of rabbit IgG and could not bind the sodium dodecyl sulfate (SDS)-denatured form. These features show the advantage of using the aptamer as a secondary probing agent rather than the usual secondary antibodies.     

Does Waist Circumference Add to the Predictive Power of the Body Mass Index for Coronary Risk?

Objectives: To examine the power of the combined measurements of body mass index (BMI) and waist circumference (WC) for the prediction of abnormality in coronary heart disease risk factors and to determine whether the additional measurement of WC is predictive in older men and women. Research Methods and Procedures: 1190 men and 751 women of the Baltimore Longitudinal Study of Aging were dichotomized into younger (<65 years) and older (65+ years) age groups. Coronary risk factors in the realms of glucose/insulin metabolism, blood pressure, and plasma lipids were assessed. The relationship of BMI and WC, singly and combined, to 10 risk factors for coronary heart disease was examined. Results: In younger and older men and women, BMI and WC are highly correlated (0.84 to 0.88). BMI and WC are also significantly correlated to all 10 coronary risk factors in younger men and women and to 8 of the 10 in the older men and women. Both partial correlation and logistic regression analyses revealed a modest but significant improvement in the prediction of coronary risk in younger men and women by WC after controlling for the level of BMI. There was no improvement in the older subjects. Discussion: WC adds only modestly to the prediction of coronary risk in younger subjects once BMI is known, and adds nothing to the production of risk in older subjects.     

Modulation of human mammary cell sensitivity to paclitaxel by new quinoline sulfonamides.

Sulfonamide derivatives of chloroquine and primaquine were synthesised and evaluated against both paclitaxel-sensitive and paclitaxel-resistant mammarian cancer cell lines. All derivatives exhibited at least 96% MDR reversal activity when co-administered with paclitaxel at 5 microM. The best compound, a chloroquine derivative, exhibited 99% MDR reversal activity when co-administered with paclitaxel at 1 microM. Molecular modelling studies reveal that these derivatives share a common pharmacophore with taxane MDR reversal agents.     

The effect of pyrazines on the metabolism of tryptophan and nicotinamide adenine dinucleotide in the rat Evidence of the formation of a potent inhibitor of aminocarboxy-muconate-semialdehyde decarboxylase from pyrazinamide

The intraperitoneal or oral administration of pyrazinamide and pyrazinoic acid (pyrazine 2-carboxylic acid) resulted in a marked increase of the NAD content in rat liver. The injections of pyrazine and pyrazine 2,3-dicarboxylic acid exhibited no significant effect on the hepatic NAD content. The boiled extract obtained from liver and kidney of rat injected with either pyrazinamide or pyrazinoic acid exhibited a potent inhibitory effect on the aminocarboxymuconate-semialdehyde decarboxylase (EC 4.1.1.45) activity in either liver or kidney, although pyrazinamide or pyrazinoic acid per se did not inhibit the enzyme activity. The unknown inhibitor of aminocarboxymuconate-semialdehyde decarboxylase was dialysable and heat-stable, and mostly excreted in urine by 6 and 12 h after injection of pyrazinoic acid and pyrazinamide, respectively. Pyrazine 2,3-dicarboxylic acid, pyrazine, nicotinamide, nicotinic acid, tryptophan, anthranilic acid, 5-hydroxyanthranilic acid and quinolinic acid exhibited no significant effect on the aminocarboxymuconate-semialdehyde decarboxylase activity in liver and kidney at the concentration of 1 mM in the reaction mixture. The expired ¹⁴CO₂ from l-[benzen ring-U-¹⁴C]tryptophan was markedly decreased by the pyrazinamide injection, while the urinary excretion of ¹⁴C-labeled metabolites from l-tryptophan, mainly quinolinic acid, was markedly increased. These results suggest that the glutarate pathway of l-tryptophan was strongly inhibited by the inhibitor produced after the administration of pyrazinoic acid and pyrazinamide. Pyrazinamide but not pyrazinoic acid also exhibited a significant inhibition of the nuclear enzyme poly(ADP-ribose) synthetase in rat liver.     

Role of Curdlan Sulfate in the Binding of HIV-1 gp120 to CD4 Molecules and the Production of gp120-Mediated TNF-α

To clarify the mechanism by which curdlan sulfate (CRDS) inhibits human immunodeficiency virus (HIV)-1 infection, we examined its influence on the binding of gp120 to CD4 molecules on T cells and macrophages, as well as on the production of TNF-α by gp120-stimulated macrophages (which promotes HIV-1 replication). CRDS treatment of cells not only inhibited the binding of HIV-1 gp120 to CD4⁺ cells, but also inhibited TNF-α production induced by gp120. Inhibition of HIV-1 infection by CRDS may be related to these two actions.     

Purification of Clostridium botulinum Type F Progenitor Toxin

Clostridium botulinum type F progenitor toxin was purified to a homogeneous state as judged by gel filtration on Sephadex G-200, ultracentrifugation, and disc electrophoresis. The sedimentation constant, corrected to water at 20 C, of type F progenitor toxin was determined to be 10.3 and the molecular weight to be 235,000 by ultracentrifugation at pH 6.0. The purified toxin contained a toxicity of 1.2 x 10(8) 50% lethal doses/mg of N. In agar gel double diffusion, it formed two precipitin lines at pH 6.0. The progenitor toxin of type F differs from that of type A in that it contains no hemagglutinin and from that of type E in that it is not activable.     

Studies on the nutrition of rice cell culture I. A simple, defined medium for rapid growth in suspension culture

We investigated the nutrient requirements of rice in liquidculture and developed a revised medium of mineral salts, sucrose,thiamine and 2,4-dichlorophenoxyacetic acid. The following majornutrients at the indicated concentrations were beneficial: NO₃-N(40 mM), NH₄-N (5.0 mM), P (2.0 mM) and K (40 mM). Cobalt, iodine,pyridoxine, nicotinic acid and m-inositol were not essentialand were excluded from the revised R-2 medium. Growth was betterwith ammonium and nitrate together than with nitrate as thesole nitrogen source. Cell growth in the R-2 medium was superiorto that obtained in B5, Heller, Murashige-Skoog and White media. (Received March 31, 1973; )