Inactivation of microbial glutamin-(asparagin-)ase by azaserine and 6-diazo-5-oxo-L-norleucine

The effect of substrate analogues on glutamin-(asparagin-)ase from Pseudomonas aurantiaca-548 has been studied. The enzyme was demonstrated to be highly sensitive to the the action of 6-diazo-5-oxo-L-norleucine and azaserine. L-isomers of glutamine, aspartate, glutamate and several other substrate analogues with free alpha-amino groups protected the enzyme against the inhibitory DON effect. Thus, thorough preliminary selection of appropriate inhibitors, their dosage and treatment duration is needed for the recommendation of combined enzyme-inhibitor application in anti-tumour chemotherapy.     

Mechanisms of retinal damage in chloroquine retinopathy

The paper presents the results of comparative electron microscopic, electrophysiological and biochemical studies of chloroquine effect on lipid peroxidation (LPO) both in vitro and in vivo (rabbits and rats). It has been shown that the progress of chloroquine retinopathy was not accompanied by the increment of the initial LPO level, and the use of ionol antioxidant did not protect the retina from the adverse effect of chloroquine. Besides, chloroquine was shown to suppress LPO in vitro. The results obtained substantiate the idea that LPO is not the primary mechanism in chloroquine retinopathy.     

Immune system function in candidiasis patients

To compare the clinical picture and the immunological characteristics, 58 candidiasis patients differing by the severity and dissemination of the disease were examined. Chronic candidiasis of the skin and mucous membranes, the most severe and disseminated form of the disease, is associated with a decrease in the number of T-lymphocytes and changes in their subpopulations, as well as high titers of Candida albicans antigen and antibodies to it in blood sera. The immune system of patients with visceral candidiasis and chronic vulvovaginal candidiasis was similar to that of healthy persons in the characteristics under study. Immediate and mixed hypersensitivity occurred in candidiasis patients more frequently than in healthy persons. In extremely severe forms of Candida infection immediate hypersensitivity prevailed.     

Angiocardiography in the diagnosis of interventricular septum defects in a double displacement of great vessels from the right ventricle]

The paper is devoted to analysis of the results of angiocardiographic investigation of 237 patients with a double deflection of great vessels (DDGV) from the right ventricle (RV) (the patients ranged in age from 3 months to 23.5 years) to study the potentialities of the method in the diagnosis of a defect position of the interventricular septum (DIVS). Angiographic investigation permitted a sufficiently accurate determination of a DIVS position in DDGV from the RV. Of paramount importance for determining a DIVS position is the establishment of the interrelationships of the latter with the infundibular septum and the openings of major arteries. For diagnosis of a DIVS position one should necessarily use left and right ventriculography both in standard and axial projections.     

Production of glycerinated models of muscle fibers with phosphorylated myosin light chains

A simple method for obtaining glycerinated muscle fibres of m. psoas of rabbit containing regulatory myosin light chains (LC2) of different levels of phosphorylation. The glycerination conditions stimulated endogenic kinase LC2 or phosphatase LC2. Glycerinated muscle fibres contained phosphorylated and dephosphorylated (levels of phosphorylation are 95 +/- 5%, and 5 +/- 5%, respectively) LC2 of myosin. To determine the level of phosphorylation the method of polyacrylamide gel electrophoresis in 8 M urea was modified.     

Regulatory Effect of Magnesium Ions on Interaction of Prolactin and Somatotropin with Receptors on Granulosum Cells of the Cow Bos taurus

A comparative study of effects of Mg²⁺ ions on specific and competitive binding of the bovine somatotropic hormone (STH) and bovine prolactin (PL) with cells of cow granulosum is carried out. It is found that Mg²⁺ increases the level of specific binding of ¹²⁵I-PL with the cells at concentrations from 1 to 70 mM and decreases the level of specific binding of ¹²⁵I-STH at a concentration of 70 mM. Analysis of the data by Scatchard's method has shown that the decrease of the level of specific binding of ¹²⁵I-PL in the absence of MgCl₂ and ¹²⁵I-STH at a MgCl₂ concentration of 70 mM is caused mainly by a decrease of the number of active binding sites on the cells. Oppositely directed effects of the studied divalent cations on the capability of unlabelled STH (25 µg/ml) and PL (25 µg/ml) for cross-suppression of specific binding of ¹²⁵I-PL and ¹²⁵I-STH, respectively, with the granulosum cells have been revealed. At the same time, with increase of Mg²⁺ ion concentration, the degree of replacement of ¹²⁵I-STH and ¹²⁵I-PL with unlabelled STH and PL, respectively, did not change. The obtained results are considered in connection with electrostatic model of participation of the divalent cations in interaction of PL and STH with receptors on cells.