Inhibition of Urease by Some Triazole, Urea, and Guanidine Derivatives

Series of aminotriazole, guanidine and urea derivatives were prepared and tested as urease inhibitors. A greater part of the tested compounds, all containing the sequence ressembling the substrate, have shown an inhibitory effect on urease

Determination of Sulfhydryl Groups in Proteins and Enzymes by Indirect Amperometric Titration

R. Hamm and K. Hofmann1,2 described in 1965 a method for the determination of sulfhydryl groups by indirect amperometric titration of proteins with silver nitrate. This method is very useful because it can be applied to turbid solutions, suspensions or homogenates of miofibrills, muscle extracts or enzymes. We modified the above mentioned method using phenylmercuric acetate instead of AgN03 for the preincubation

Antifungal Activity and Inhibitory Effect on Urease of Some Organo-Mercuric Compounds

A number of aliphatic and aromatic organo-·mercuric compounds of the general formula R-Hg-X, in which R represents a n organic radical and X an anionic radical, were prepared. The antifungal and inhibitory effect of the tested compounds was compared by app ly1ng the aiuxa nographic diffusion method and by measuring the degree of inhibition of urease. It was found that the antifungal activity d epends mainly on the organic radical R and that the antonic radical h as no effect on fungitoxicity

Grazing-Incidence Neutron Optics based on Wolter Geometries

The feasibility of grazing-incidence neutron imaging optics based on the Wolter geometries have been successfully demonstrated. Biological microscopy, neutron radiography, medical imaging, neutron crystallography and boron neutron capture therapy would benefit from high resolution focusing neutron optics. Two bounce optics can also be used to focus neutrons in SANS experiments. Here, the use of the optics would result in lower values of obtainable scattering angles. The high efficiency of the optics permits a decrease in the minimum scattering vector without lowering the neutron intensity on sample. In this application, a significant advantage of the reflective optics over refractive optics is that the focus is independent of wavelength, so that the technique can be applied to polychromatic beams at pulsed neutron sources

The Isolation and Kinetics of Lactoperoxidase

The catalatic and peroxidatic activities of lactoperoxidase and horse-ra dish peroxidase are described. For measuring the peroxidatic activity. pyrogallol was used as a hydrogen donor. A manometric m ethod was used for the determination of the Km value. The Km value for the catalatic reaction was calculated on the basis of 0 2 evolved, a nd the peroxidatic reaction was calculated on the basis of C02 evolved. In the catalatic reaction the efficiency of lactoperoxidase and horse-radish peroxidase are of the same order. The peroxidatic activity of lactoperoxidase is higher than that of horse-radish peroxidase. The mechanism of peroxidase action was interpreted as described by Chancet

Action of 1,6-Dimethyl-SB-(Bromoisonicotinoyl-Oxymethyl)-10a- Methoxyergoline (SermionR) on Some Molecular Processes in the Brain

The influence of SermionR on cellular protein synthesis in the mouse brain was studied in vivo, after an intraperitoneal administration of 50 microgram doses. The brain samples analyzed at different intervals after drug treatment showed a short-term increase of 3H-Leucine incorporation into proteins, followed by a. gradual decline of uptake. The latter reached control levels about 18 h after drug administration. Under similar experimental treatments Sermion had no effect on the synthesis of RNA catalyzed by Mg++- ions; however, a slight stimulation of the Mn++- activated RNA synthesis was obserwed. Mice receiving i. p. injections of 50 micrograms of Sermion showed an increased brain rnethyltransferase activity; the maximum stimulation was observed one hour after drug treatment. In another set of experiments the capacity of mouse brain preparations to catalyze the methyl group incorporation into the exogenously added transfer RNA (tRNA) was found to decrease with increasing age of the animals; the addition of 10-4 M Sermion to the incubation medium enhanced endogenous rnethylation, especially in the older animals. On the other hand the capacity to methylate the exogenously added heterologous tRNA was not effected by Sermion, irrespective of the age of the animals. In an attempt to understand the physiological relevance of the biochemical effects of Sermion, we have carried out some studies on the effect of this drug on conditioned learning in rats. The preliminary data indicate that the drug is able to enhance the learning quotients, however, more experiments are in progress to reach a definitive conclusion

Determination of Sulfhydryl Groups in Proteins and Enzymes by Indirect Amperometric Titration

R. Hamm and K. Hofmann1,2 described in 1965 a method for the determination of sulfhydryl groups by indirect amperometric titration of proteins with silver nitrate. This method is very useful because it can be applied to turbid solutions, suspensions or homogenates of miofibrills, muscle extracts or enzymes. We modified the above mentioned method using phenylmercuric acetate instead of AgN03 for the preincubation

Identification and characterization of two novel primate-specific histone H3 variants, H3.X and H3.Y

The expression of a new histone variant H3.Y increases during cellular stress to regulate cell cycle progression and gene expression