Morphofunctional research on the interrenal gland of the frog Rana temporaria following arginine vasotocin administration

Studies have been made of the effect of injections of hypothalamic nonapeptide neurohormone, arginine vasotocin, on functional condition of the interrenal gland in mature frogs. In unoperated, sham-operated and in animals 10 days after hypophysectomy, single and especially three subsequent injections of arginine vasotocin (5 x 10(-9) M per 1 kg of the body weight) result in evident activation of glandular cells of the interrenal gland which is manifested in the increase of the volume of their nuclei and cytoplasmic area, as well as in the dilatation of the blood vessels. Activation of the interrenal gland in hypophysectomized frogs, which lack endogenous ACTH, indicate the direct para-adenohypophyseal influences of nonapeptide hypothalamic hormones on the activity of glandular cells in the peripheral endocrine glands, in particular, the interrenal gland of the grass frog.     

Sequence divergence of the mitochondrial DNA of Pacific Ocean salmon

Restriction assay of mtDNA has been made in 6 salmon species form the genus Oncorhynchus and one species from the related genus, i.e. Salvelinus malma. The size of the mitochondrial genome was found to be identical and equal to 16.7 kilobases. The digestion patterns of mtDNA cleaved by 5 restriction endonucleases (Eco RI, Bgl I, Bgl II, Hind III, and Pst I) were used for analysis of the levels of interspecific variation and for estimation the matrix of mtDNA sequence differentiation. It was found that the level of nucleotide sequence divergence (p) in the genus Oncorhynchus varies within 1.7-6.7%. Minimum p value was observed in a pair O. keta--O. gorbuscha, maximum one--between O. masu and other species. With respect to similarity in their mtDNA, three groups may be distinguished: 1) O. gorbuscha--O. keta; 2) O. nerka--O. kisutch, O. tschawytscha; 3) O. masu. Mean value of intergeneric level of sequence divergence between Oncorhynchus and Salvelinus was found to be equal to 8%. On the basis of mtDNA analysis, the dendrogram of similarity of the species was plotted which is consistent in principle with current viewpoints on phylogenetic relations among the Pacific salmon.     

Ultrastructure of HeLa cella after exposure to nickel ions

Dose-dependent progress of destructive processes (mitochondria destruction, proteolysis, autophagocytosis) is observed in HeLa cells treated with various concentrations of nickel (0.05-4 micrograms/ml) for 2, 4 and 24 hours. Parallel with it the compensation and adaptation responses of cells (increase of mitochondrion polymorphism, appearance of "macropolysomes", hypertrophy of the Golgi complex) take place.     

Coenzyme reorientations in the active sites of aspartate aminotransferase isoenzymes studied by linear dichroism method

Cytosolic and mitochondrial pig heart aspartate aminotransferases (cAspAT and mAspAT) and chicken heart cAspAT have been oriented in a compressed slab of polyacrylamide gel and their linear dichroism LD spectra have been recorded. The coenzyme's tilt angles in the active sites of chicken cAspAT and pig mAspAT and their quasisubstrate complexes imitating catalytic intermediates have been computed. The computations are based on reduced linear dichroism values (delta A/A), the known directions of the transition dipole moments in the coenzyme ring and atomic coordinates of the coenzyme obtained by X-ray crystallography. It has been found that formation of the enzyme complex with glutarate and protonation of the internal pyridoxal-lysine aldimine induce reorientations of the coenzyme. As a result of protonation, the coenzyme ring tilts by 27 degrees in cAspAT and 13 degrees in mAspAT. Formation of the external aldimine with 2-methylaspartate is accompanied by tilting of the coenzyme ring by 44 degrees in cAspAT and 39 degrees in mAspAT. For the quinonoid complex with erythro-3-hydroxyaspartate, the tilt angles were found to be 63 degrees in cAspAT and 53 degrees in mAspAT. It is inferred that the basic features of the active site dynamics are similar in the three AspAT's studied. The differences in the coenzyme tilt angles between cAspAT and mAspAT may be linked to catalytic and structural peculiarities of the isoenzymes.     

A clinico-physiological study of the mechanism of the cholecystokinetic action of medicinal mineral waters of the naftusia type]

It is stated that the cholecystokinetic action of curative waters of naftusia type is due to the interaction of its organic substances, particularly bitumens, with mucous membrane of gastroduodenal zone by the intramural reflex mechanism with participation of humoral factor. It is indicated by attenuation or suppression of the effect by pharmacons interrupting the work of interchemoreception, N- and M-cholinoreceptors, beta-adrenoreceptors; intensification of the effect by blockade of alpha-adrenoreceptors; its reversion by nonselective stimulation of adrenoreceptors; release of gastrin, glucagon and insulin into blood.     

Selection and physiological study of culture of Bacillus circulans-- producer of butirosin]

For isolating a highly active variant of the butirosin-producing culture, a strain forming trace amounts of the antibiotic substance was used. Exposure to nitrosomethylbiuret and nitrosoguanidine and the use of selective media containing streptomycin and butirosin resulted in a 30-fold increase in the strain productivity. Thin layer chromatography of the produced antibiotic substance in the solvent system developed by the authors, mass spectrometry and assay of the antimicrobial spectrum in regard to ++gram-positive and ++gram-negative bacteria by using the known aminoglycosidine-inactivating enzymes revealed that the substance was identical to butirosin. Along with the major product, the fermentation broth contained up to 5 per cent of ribostamycin.     

Antibiotic therapy of children in a gnotobiological unit]

The clinical effect of antibiotics in treatment of children at the age of 2 months to 5 years with acute pneumonia during a gnotobiological department in the wards of the 1st class purity and under the conditions of a routine pediatric hospital was estimated. The course of the antibiotic therapy amounted to 4.7 +/- 0.42 days in the gnotobiological department and 12.0 +/- 0.3 days in the routine hospital. After recovery the patients were discharged in 7.61 +/- 0.76 days from the gnotobiological department and in 15.2 +/- 1.11 days from the routine hospital.     

Catalytic effect of gamma-thrombin on synthetic low molecular weight peptide substrates]

Hydrolysis and respective catalytic parameters of hydrolysis of ester peptide substrates that contain residues of hydrophobic and nonpolar amino acids in P2, P3 subsites have been studied. It is shown that efficiency of hydrolysis by thrombin is determined by the length of polypeptide chains and by the nature of the amino acids in P2, P3 subsites in the substrate. In spite of the fact that gamma-thrombin retains the conformation activity of the catalytic centre the local conformation changes of the second binding region of the enzyme have been discovered.     

Effect of stress factors on carboxypeptidase H activity in areas of the rat brain]

It is established that carboxypeptidase H activity increases as affected by various stress factors in the rat brain departments. The increase of the enzyme activity because of the emotional-pain stress is of continuous character. Possible role of carboxypeptidase H in the development of the stress response is discussed.