Effect of repeated partial hepatectomy on cell division in the regenerating rat liver

Repeated partial hepatectomy (PH), performed 24 h after a 70% PH, had the following effect on the mitotic cell cycle in the regenerating rat liver: it delayed (by about 2 h) the cells in the G₂ period, left the S period almost unchanged, and delayed the cells for 6–8 h in the G₁ period. A mock repeated operation had a similar effect. This indicates that the influence of the repeated PH on the mitotic cell cycle in the regenerating liver is due to operation stress. Additional stimulation of division by repeated PH affects the character of the regeneration process as a whole.Laboratory of Chemical Factors of Regulation of Growth and Cell Division, Institute of Biological and Medical Chemistry, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. N. Orekhovich.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 10, pp. 488–491, October, 1977.     

Effect of various factors on the formation of immunological memory

Experiments on mice in which sheep's red cells were used as antigen showed that the height of the secondary immune response of spleen cells in situ or in adoptive transfer is inversely proportional to the dose of red cells used for primary immunization. Cyclophosphamide, injected into the animals simultaneously with the antigen, stimulates the immune response of the mice to the second injection of red cells, but this effect is observed only when comparatively large doses of antigen are used for priming. The mechanisms of this phenomenon are discussed.Laboratory of Immunogenetics, Institute of Medical Genetics, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. N. Zhukov-Verezhnikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 9, pp. 336–339, September, 1977.     

Electron-microscopic study of interaction between cytolytic T lymphocytes and target cells

Thymocytes stimulatedin vitro in mixed culture were adsorbed by centrifugation on to the surface of target cells for an electron-microscopic study of the cytology of immune T lymphocytes and of the early stages of cytolysis. A well-developed Golgi apparatus and clusters of tubular structures 50–60 nm in diameter, communicating with the cisternae of the granular endoplasmic reticulum, with emptied vesicles, and with the plasma membrane of the lymphocyte, were found in the cytoplasm of the lymphocytes. Over a wide area the plasma membrane formed numerous contacts with the membrane of the target cells, so that closed slit-like spaces were formed. With these data and also modern views regarding interconversion of membranes and intracellular transport in mind, a hypothetical scheme for the mechanism of cytolysis of the target cell by the immune T lymphocyte is suggested.Oncologic Scientific Center, Academy of Medical Sciences of the USSR, Moscow. N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR O. V. Baroyan.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 10, pp. 443–447, October, 1977.     

Effect of dimethylsulfoxide on transformation ofBacillus subtilis in vitro

Transformation ofBacillus subtilis was carried out in the presence of dimethyl sulfoxide and polyethylene glycol. The frequency of transformation ofB. subtilis was increased by 0.1% dimethyl sulfoxide but was not appreciably changed by polyethylene glycol. It is suggested that the increase in frequency of transformation was due to the effect of dimethyl sulfoxide on permeability of the cell membrane or to changes in membrane deoxyribonuclease activity.Research Laboratory of Experimental Immunobiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. N. Zhukov-Verezhnikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 11, pp. 556–557, November, 1978.     

Mechanism of disturbances of energy formation in acute ischemia of the liver

Respiration of rat liver mitochondria after the addition of ischemic toxin to the incubation medium was compared with respiration of mitochondria isolated from ischemic rat liver. The changes in respiration in both cases could be prevented by preliminary addition of dithiothreitol and reduced by subsequent addition of cytochrome c or dithiothreitol to the incubation medium. The similarity between the mechanisms of disturbance of energy formation is postulated.Laboratory of Transplantation of Organs and Tissues, Academy of Medical Sciences of the USSR, Moscow. Institute of Clinical and Experimental Medicine, Academy of Medical Sciences of the USSR, Siberian Branch, Novosibirsk. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Kovanov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 9, pp. 301–303, September, 1977.     

Effect of ethimizole on energy metabolism in the rat brain

In a dose of 25 mg/kg, 20 min after intraperitoneal injection, ethimizole stimulates oxidative phosphorylation, increases the creatine phosphate content and reduces the concentration of inorganic phosphorus in the brain tissue of rats. It is postulated that ethimizole stimulates energy metabolism through its activating effect on adenyl cyclase.Laboratory of Experimental Pharmacology, Department of Pharmacology, Institute of Experimental Medicine, Academy of Medical Sciences of the USSR, Leningrad. (Presented by Academician of the Academy of Medical Sciences of the USSR S. V. Anichkov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 2, pp. 185–187, February, 1977.     

Transport of chlorine ions in parietal cells of the gastric mucosa: Electron-histochemical and autoradiographic investigation

The location of chlorine ions in the parietal cells of the mouse and rat gastric mucosa was studied by electron-histochemical and autoradiographic methods together with the direct method of detection of radioactive isotopes in tissue. On the basis of the results a scheme of specific transport of chlorine ions is proposed and envisages the transposition of individual layers of the cell membrane, double folds of the basal plasmalemma, tubulovesicles, and intracellular tubules. This interconversion takes place in the course of the secretory cycle of the cell and is directly dependent on it. A nonspecific pathway for the transport of the total chlorides of the gastric juice across intercellular spaces is postulated.Laboratory of Pathomorphology, Institute of Nutrition, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Kraevskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 7, pp. 29–32, July, 1977.     

Some kinetic features of membrane-bound monoamine oxidase

Initial reaction-velocity versus substrate-concentration curves for serotonin oxidation catalyzed by monoamine oxidase (MAO) from fragments of rat liver or bovine brain mitochondrial membranes have a complex, nonhyperbolic shape; this is regarded as a kinetic manifestation of substrate cooperativeness for membrane-bound MAO. The possibility of interaction between different types of MAO based on conformational changes in the membrane itself is discussed.Scientific-Research Institute for Biological Trials of Chemical Compounds, Ministry of the Medical Industry of the USSR. Institute of Biological Medical Chemistry, Academy of Medical Sciences of the USSR. All-Union Vitamin Scientific-Research Institute, Ministry of the Medical Industry of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. N. Orekhovich.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 3, pp. 288–289, March, 1977.     

Adjuvant action of fragments of the IgG molecule present in the serum of partially hepatectomized rabbits

Fragments of the IgG molecule, related to Fab, present in the blood serum of partially hepatectomized rabbits, have the property of intensifying the immune response of rabbits through xenogeneic erythrocytes. After simultaneous injection of sheep's erythrocytes and the Fab-like fragment into rabbits there was an increase in the number of antibody-producing cells in the spleen and in the titers of 19S and 7S hemagglutinins.Kursk Medical Institute. N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR G. V. Vygodchikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 2, pp. 206–208, February, 1976.     

Development of interneuronal synapses between anterior horn neuroblasts of the human spinal cord in early prenatal development (seventh to ninth weeks of gestation)

Synaptogenesis in presumptive anterior horn cells of the spinal cord (C4-T3) was studied by electron microscopy in early human prenatal development. The morphological stages of synaptogenesis were traced and the minimum structural organization of the synapse corresponding to the onset of its functional activity was identified. The possible mechanisms of synaptogenesis are postulated.Laboratory of Development of the Peripheral Nervous System, Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 2, pp. 233–235, February, 1977.     

Effect of sympathomimetic agents and dopa on the ultrastructure of the nervous apparatus of the heart

After a single injection of noradrenalin or dopa into albino rats noradrenalin was incorporated into adrenergic axons of the heart and deposited as granules in the small synaptic vesicles measuring about 30 nm in diameter. In this way adrenergic axons could be distinguished from cholinergic. Cholinergic axons were more numerous than adrenergic in the atria. Adrenergic terminals come into very intimate contact with cholinergic terminals and also withcapillary endothelial cells and muscle cells of the myocardium. It is postulated that adrenergic fibers may act on heart muscle in three ways: by means of presynaptic inhibition through cholinergic axons, by a humoral mechanism, and directly on the muscle cells of the myocardium.Laboratory of Cytology, Scientific-Research Institute of Experimental Medicine, Academy of Medical Sciences of the USSR, Leningrad. (Presented by Academician of the Academy of Medical Sciences of the USSR S. V. Anichkov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 11, pp. 1382–1385, November, 1976.     

Synchronization of cell proliferation in sarcoma 37 of mice by hydroxyurea

The synchronizing action of hydroxyurea on the passage of sarcoma 37 cells through the S phase and mitosis was investigated in mice, allowing for diurnal fluctuations in mitotic activity and the index of labeled nuclei. The degree of synchronization was estimated from changes in the number of proliferating or labeled cells and the rate of change of synchronization. The tumor consisted of at least two cell populations in which variations in the number of cells both in the S period and also, probably, in mitosis were out of phase. The degree of artificial synchronization of the cells in mitosis based on the rate of change of synchronization was much higher than the natural level in the tumor not divided into separate populations. However, the number of cells undergoing artificial synchronization was not significantly different not only from the number of cells in the tumor undivided into separate populations, but also from the number of cells naturally synchronized in one of the populations. A possible explanation of this fact is that hydroxyurea acted on only one group of cells, for fluctuations in the number of DNA-synthesizing cells in the separate populations also were out of phase.Laboratory of Growth and Development, Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. Department of General Biology, N. I. Pirogov Second Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 11, pp. 1352–1354, November, 1976.     

Comparative study of the action of ethimizole and hydrocortisone on proliferative activity and protein synthesis in epithelial cells of the tongue and liver

Unlike hydrocortisone, ethimizole stimulated mitotic activity of the epithelial cells of the tongue and liver 6 h after its administration. The decrease in the number of mitoses in the hepatocytes after 12 h was due to the action of both substances on DNA synthesis and not to a disturbance of the entry of the cells into mitosis. Stimulation of protein synthesis was detected by autoradiographic and biochemical methods following the action of hydrocortisone and ethimizole at the maximum of inhibition of mitosis.Laboratory of Experimental Histology, Institute of Experimental Medicine, Academy of Medical Sciences of the USSR, Leningrad. (Presented by Academician of the Academy of Medical Sciences of the USSR S. V. Anichkov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 3, pp. 348–350, March, 1977.     

Orientation of nonspherical cells in blood flowing through a vessel

Photometric experiments on model blood vessels showed that nonspherical blood cells are oriented in the flow with their short axes along the radius of the vessel.All-Union Cardiological Scientific Center, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR E. I. Chazov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 11, pp. 631–632, November, 1978.     

Role of macrophages in the mechanism of specific retention of sensitized lymphocytes in lymph glands containing antigen

The role of macrophages in the phenomenon of specific retention of antigen-activated. lymphocytes in lymph glands containing the same antigen was investigated. Injection of peritoneal macrophages, phagocytosing sheep's red cells (as well as of the red cells alone) was found to cause specific retention of lymphocytes in the regional lymph glands. Preliminary treatment of the antigen-loaded macrophages with antierythrocytic serum reduced the retention of lymphocytes. It is postulated that lymphocytes are fixed by means of receptors on their surface to the membrane of macrophages, into which antigen molecules are incorporated.Laboratory of Histochemistry and Molecular Pathology, Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 3, pp. 345–347, March, 1976.     

New data on the fine structural organization of the subsynaptic zone of the nerve cell

The fine structural organization of the subsynaptic zone of the nerve cell was studied by electron microscopy. This zone of the neuron was shown to be directly connected with special intracellular organelles or microtubules. Their peripheral ends, expanded like funnels, are in close contact with the postsynaptic membrane and apparently merge with its inner osmiophilic layer. These observations definitely show that direct structurally organized connections exist between the synaptic region of the neuron and the deep layers of its cytoplasm. A hypothesis to explain the functional role of these connections is put forward.Laboratory of Development of the Peripheral Nervous System, Institute of Human Morphology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 10, pp. 502–505, October, 1977.     

Cytological analysis of the secretory epithelium of the rat submandibular salivary glands hypertrophied after repeated amputation of the lower incisors

Repeated amputation of the lower incisors in August rats causes hypertrophy of the submandibular and sublingual salivary glands. Hypertrophy of the submandibular salivary glands is true in character and accompanied by hypertrophy of the structural components (acini, cells, nuclei). Hypertrophy of the cells is due to hypertrophy of the cell organelles and the accumulation of secretory masses in the cell. Hypertrophy of acinar cell nuclei is connected with polyploidization. Polyploidization and ultrastructural changes in the cells of the submandibular salivary gland are evidence of the increased functional activity of that organ.Laboratory of Growth and Development, Institute of Human Morphology, Academy of Medical Sciences of the USSR. Department of Cytology and Histology, M. V. Lomonosov Moscow State University. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 3, pp. 377–378, March, 1976.     

Inhibitory action of neuraminidase ofVibrio cholerae in Rauscher mouse leukemia

The inhibitory action of the neuraminidase ofVibrio cholerae in Rauscher mouse leukemia was studied. After treatment of the spleen cells of leukemic mice with neuraminidase in doses of 50 units/ml or more, the ability of these cells to induce leukemia when injected into BALB/c mice was inhibited significantly. Neraminidase in the above concentration, if given by repeated parenteral injection, had no therapeutic action in Rauscher leukemia.D. I. Ivanovskii Institute of Virology, Academy of Medical Sciences of the USSR. Scientific-Research Laboratory of Experimental Immunobiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. N. Zhukov-Verezhnikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 11, pp. 1357–1359, November, 1976.     

Study of the chemical receptor for diphtheria toxin in cell membranes

Adsorption of diphtheria toxin on immobilized preparations of cell membranes was studies in the presence of gangliosides. A mixture of gangliosides completely suppresses adsorption of the toxin on membranes of cells both sensitive (HeLa cells, macrophages) and resistant (L cells) to its action. Gangliosides treated with neuraminidase are less effective. Immobilized gangliosides effectively adsorb diphtheria toxin in the presence of protective colloid and of the detergent Triton X-100. On the basis of these results gangliosides can be regarded as the receptors of diphtheria toxin.N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR O. V. Baroyan.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 85, No. 5, pp. 549–551, May, 1978.     

Cytopharmacological effect of polyvinylpyridine-N-oxide in experimental silicosis

The development of experimental silicosis during simultaneous administration of polyvinylpyridine-N-oxide was studied by scanning and transmission electron-microscopic and cytochemical methods. Most macrophages were found to preserve their active function and to phagocytose quartz and to remove it through the air passages. In the fibroblasts the liberation of proteins onto the cell surface was delayed and the intensity of formation of collagen fibers was reduced. Administration of the polymer prevented the development of fibrosis of the lungs.Laboratory of Pathomorphology, Institute of Work Hygiene and Occupational Diseases, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. V. Smol'yannikov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 3, pp. 371–374, March, 1977.