A study of hexokinase isoenzymes in rat sarcoma M-1

Using a wide spectrum of criteria, the isozyme composition of hexokinase from sarcoma M-1 reinoculated to rat m. gastrocnemius was studied. The structural, physicochemical and functional properties of the homogeneous enzyme which is represented in sarcoma M-1 by one molecular form, were investigated. Some properties of the enzyme (amino acid composition, resistance to mild proteolysis, Mr, pH-dependence of enzyme activity, electrophoretic mobility, kinetic behaviour) indicate that sarcoma M-1 hexokinase is a specific form of the enzyme which differs markedly from other known isozymes of mammalian hexokinase. The observed peculiarities of sarcoma M-1 hexokinase are discussed in terms of present-day concepts on the structure of isozymic spectra of enzymes in neoplastic tissues.     

Effect of low doses of internal irradiation resulting from the administration of 75Se- and 35S-labeled compounds on the cellular immune response

The administration to rats of radioactive preparations. 75Se- selenomethionine, 35S-methionine or sodium 75Se-selenite in the amounts creating the absorbed dose in the body of 0.5 Gy suppressed the delayed hypersensitivity reaction as was registered 1-12 months after the injection. The delayed hypersensitivity was tested in vitro by the method of inhibimacrophage spreding inhibition. The degree of suppression of the cellular immune response depended upon the type of the compound administered, of which the radionuclide was a component, and upon characteristics of radiation spectrum of the radionuclide.     

Ultrastructure of the L forms of Streptococcus group B

The submicroscopic organization of the L-forms of beta-hemolytic streptococci of group B has been studied in the course of their cultivation. The L-forms of group B streptococci differ from those of group A streptococci by a higher growth rate. On the submicroscopic level, the activity of ATP-ase has been revealed on the internal side of the cytoplasmic membrane. Regularities in the localization of intramembranous particles sized 6-18 nm in the hydrophobic area of the membrane have been established by means of freezing-etching. With the adequate methods of fixation, the continuous three-layer structure of the cytoplasmic membrane can be determined in all elements of the L-form population.     

The HPA Axis under Stress and Aging: Individual Vulnerability is Associated with Behavioral Patterns and Exposure Time

With aging, incidence of severe stress-related diseases increases. However, mechanisms, underlying individual vulnerability to stress and age-related diseases are not clear. The goal of this review is to analyze finding from the recent literature on age-related characteristics of the hypothalamic-pituitary-adrenal (HPA) axis associated with stress reactivity in animals that show behavioral signs of anxiety and depression under mild stress, and in human patients with anxiety disorders and depression with emphasis on the impact of the circadian rhythm and the negative feedback mechanisms involved in the stress response. One can conclude that HPA axis reaction to psycho-emotional stress, at least acute stress, increases in the aged individuals with anxiety and depression behavior. Elevated stress reactivity is associated with disruption of the circadian rhythm and the mineralocorticoid receptor-mediated glucocorticoid negative feedback. The disordered function of the HPA axis in individuals with anxiety and depression behavior can contribute to aging-related pathology.     

Serological and epidemiological characteristics of acute pneumonias caused by Mycoplasma pneumoniae in Belgorod

The etiology of the outbreaks of acute pneumonia in Belgorod was established and their epidemiological features were studied. The mycoplasmal etiology of all cases of acute pneumonia in children and adults, appearing alongside acute respiratory infections resulting from the preceding outbreaks caused by influenza viruses A/Prague/, B/Leningrad/369/75, and all types of parainfluenza viruses, was shown. The droplet mechanism of the transfer of infection was established, which was confirmed by the severity of the outbreak and a high rate of infection of the medical staff at hospitals for children and adults, where patients with mycoplasma-induced pneumonia were treated.