Mechanism of the stimulating action of an electric current on reparative regeneration of bone tissue

The dynamics of the ATP concentration in regenerating bone tissue was studied in experiments on rabbits after incomplete osteotomy or resection of a piece of bone and also during stimulation of reparative osteogenesis in the region of a bone defect by means of a pulsed electric current. The ATP concentration in the callus after incomplete osteotomy and during electrical stimulation was found to be higher than in regenerating bone tissue after resection of the bone fragment in the absence of stimulation. It can be concluded that improvement of the energy supply for fracture healing is an important factor in the mechanisms of the stimulating effect of an electric current on reparative regeneration of bone tissue.Laboratory of Biophysics and Radiological Department, N. N. Priorov Central Research Institute of Traumatology and Orthopedics, Ministry of Health of the USSR. Clinical Diagnostic Laboratory, A. V. Vishnevskii Institute of Surgery, Academy of Medical Sciences of the USSR, Moscow. Moscow Energy Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR M. V. Volkov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 9, pp. 361–362, September, 1978.     

Binuclear rat liver cells during reparative regeneration of the organ

In the early stages after partial hepatectomy (17 h after the operation) binuclear cells take part in proliferation (the number of binuclear cells in proportion to the total number of cells labeled 1 h after injection of thymidine-³H was considerably smaller, whereas in the later stages (37 and 53 h after the operation) their relative fraction in the population was twice or three times greater. The formation of new binuclear cells from mononuclear cells (reflected in the number of labeled binuclear cells 20 h after injection of thymidine-³H) took place most intensively in the early periods of regeneration (16–36 h after the operation) when about 20% of mitoses were acytokinetic and led to the formation of a binuclear cell. In the later periods only 8% of mitoses ended with the formation of binuclear cells.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. 87, No. 4, pp. 347–349, April, 1979.     

Humoral mechanisms of regulation of reparative osteogenesis

The effect of the blood serum from animals with active osteogenesis on the biosynthesis of nucleic acids and protein and on mineralization of regenerating bone tissue was studied in experiments in vivo and in vitro. Incorporation of labeled precursors of DNA ([³H]thymidine) and protein ([¹⁴C]proline) in the recipients was intensified and mineralization of bony callus (incorporation of⁸⁵Sr) was accelerated. Comparison of the order of stimulation of nucleic acid and protein synthesis suggests that the active principle of the serum promotes more rapid cell proliferation in the fracture zone.Laboratory of Pathophysiology and Laboratory of Biochemistry, Research Institute of Experimental and Clinical Orthopedics and Traumatology, Kurgan. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Fedorov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 12, pp. 725–727, December, 1977.     

Changes in mitotic activity and destruction of lymphocytes in the rat thumus after hydrocortisone administration at different times of day

A similar type of diurnal rhythm of the number of mitoses was found in the lymphocytes of the thymus of 30-day-old rats 4 h after injection of hydrocortisone and in control animals. The number of dying lymphocytes in the control rats did not change during the 24-h period. The number of destroyed cells rose sharply 4 h after injection of hydrocortisone, but the degree of destruction of the lymphocytes was greater during the night and early morning than during the afternoon and evening.Department of 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. 84, No. 11, pp. 611–613, November, 1977.     

Effect of restoration of visual impulses on energy metabolism in the visual system of the brain in dark-reared animals

Changes in the rate and character of energy metabolism in the mitochondria, of the visual system of the brain induced by prolonged visual deprivation (from birth until the age of 2.5 months) were shown to be reversible. The degree of normalization differed for mitochondria of the visual cortex and superior colliculus. During the 2-week recovery period (when the animal was transferred to ordinary conditions of illumination) the rate of these processes increased, when glutamic acid was used as the substrate, and reached the control level or exceeded it somewhat. The rate of electron transport in the cytochrome c-cytochrome oxidase section of the succinate oxidase oxidation chain, which was increased during deprivation, diminished in the recovery period and came close to the control level The role of specific impulse activity in the formation of mitochondrial energy processes in the brain with age is discussed.Laboratory of Biohistochemistry, Institute of the Brain, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. N. Klosovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 9, pp. 1066–1068, September, 1976.     

Cholerogen and neuraminidase production by cholera Vibrios in vitro

A high degree of rank correlation between the synthesis of cholera exotoxin and neuraminidase by cholera vibrios (Vibrio cholerae 569 B) was demonstrated by experiments in vitro, and the appearance of these biologically active substances was shown to depend on the phase of development of the microbial population. It is suggested that they act cooperatively during the development of cholera.Volgograd Plague Institute. Research Laboratory of Experimental Immunobiology, Academy of Medical Sciences of the USSR. (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. 81, No. 5, pp. 566–568, May, 1976.     

Ability of thermo- and acid-stable serum serine protease inhibitor to inhibit mitogen-stimulated transformation of lymphocytes

The ability of a thermostable and acid-stable serine protease inhibitor from rabbit blood serum (TASPI) to inhibit the transformation of human peripheral blood lymphocytes stimulated by phytohemagglutinin (PHA) or concanavalin A (con A) was demonstrated. The degree of inhibition depends on the concentration of the inhibitor and its specific activity. The maximal degree of inhibition was 50–70%. TASPI has no cytotoxicity. Stronger inhibition of transformation is observed if TASPI is added to the culture 24 h after the addition of PHA. Data on the antiprotease activity of human blood serum, either native or inactivated under different conditions, are given. The results suggest that TASPI participates in the control of the biological activity of lymphoid tissue cells.Laboratory of Immunogenetics, Institute of Transplantation of Organs and Tissues, Ministry of Health of the USSR. Laboratory of Biochemistry and Pathochemistry of Vasoactive Polypeptides, 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 Biology i Meditsiny, Vol. 85, No. 5, pp. 569–572, May, 1978.     

Effect of cycloheximide on protein,RNA, and DNA synthesis in CHO and diploid human fibroblast cell cultures

All-Union Medical Genetics Research Center, Academy of Medical Sciences of the USSR, Moscow. Chernogolovka Branch, N. N. Semenov Institute of Chemical Physics, Moscow Region. (Presented by Academician of the Academy of Medical Sciences of the USSR N. P. Bochkov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 112, No. 8, pp. 139–141, August, 1991.     

Action of acute cardiac ischemia on activity of the protein-synthesizing system of the inner mitochondrial membranes of the myocardium

Acute cardiac ischemia caused by ligation of the descending branch of the left coronary artery leads to a sharp increase in the activity of the protein-synthesizing system of the inner mitochondrial membranes of the myocardium throughout the period of organization of the experimental infarct, as reflected in an incease in the synthesis of protein and RNA in the mitochondria. During development of the infarct considerable changes are observed in the ultrastructure of the inner mitochondrial membranes of the myocardium, the degree of which is directly dependent on the stage of development of the pathological process.Institute of General Pathology and Pathophysiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. N. Chernukh.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 9, pp. 295–297, September, 1978.     

Conditions affecting induction of osteogenesis after implantation of bone matrix into mice

Induction of osteogenesis was observed in 90–100% of cases of implantation of decalcified bone matrix intramuscularly into mice, beneath the kidney capsule, beneath the kidney capsule after ligation of the blood vessels, and intramuscularly into animals after curettage of the medullary canal of the femur. No morphological differences were found under these circumstances. Both implants with large bone lamellae filled with medullary cells and implants with small areas of osteogenic tissues were found in each series of experiments. It is concluded that the induction process is independent both of the degree of vascularization of the implantation site and of the degree of calcification of the surrounding tissue, and it is evidently determined by the presence of inducible cells susceptible to the induction stimulus.Laboratory of Immunomorphology, 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 P. A. Vershilova.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 89, No. 1, pp. 45–46, January, 1980.