Toxicity and proteolysis in germfree rats with thermal burns

The toxic properties of the organs and activity of proteolytic enzymes in them were studied in experiments on germfree rats after thermal burns. In the absence of a pathogenic microflora a state of toxemia was found to develop and the proteolytic enzyme activity was increased. The intensity of the toxic and catabolic reactions depended on the severity of the burns. The toxic manifestations and increase in proteolysis in the germfree rats were in some cases more marked than in ordinary animals. It is concluded that tissue sources of toxic products play an important role in burns.Laboratory of Biochemistry, A. V. Vishnevskii Institute of Surgery, Academy of Medical Sciences of the USSR. Laboratory of Pathological Physiology, Central Institute of Hematology and Blood Transfusion, and Laboratory of Experimental Models, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR N. A. Fedorov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 12, pp. 1444–1445, December, 1976.     

Stimulation of mitotic activity of the hepatocytes and kupffer cells of the liver of intact mice by T- and B-lymphocytes of partially hepatectomized syngeneic donors

T-lymphocytes from the spleen of partially hepatectomized CBA mice enhance the mitotic activity of hepatocytes and Kupffer cells of the liver in nonoperated recipients. The proliferation induced by these cells is equal to the inductive capacity of the whole suspension of lymphocytes from the spleen of partially hepatectomized animals, which contain T- and B-lymphocytes. The proliferation induced by B-lymphocytes from the spleen of operated mice is significantly lowered and is displayed chiefly in relation to Kupffer cells.Laboratory of Growth and Development, Institute of Human Morphology, Academy of Medical Sciences of the USSR. Laboratory of Immunology, Moscow Institute of Epidemiology and Microbiology, Ministry of Health of the USSR. (Presented by Academician of the Academy of Medical Sciences of the USSR A. P. Avtsyn.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 89, No. 1, pp. 69–70, January, 1980.     

Changes in intracellular ribonuclease activity in the rat liver during inhibition of protein synthesis by cycloheximide

Injection of cycloheximide into rats was shown not to change the acid and alkaline ribonuclease (RNase) activity in the cytoplasm of liver cells. Meanwhile inhibition of protein synthesis by cycloheximide led to a decrease in RNase activity of microsomes and membrane-bound polysomes. RNase activity of free polysomes in liver cells was considerably increased after administration of cycloheximide.Laboratory of Enzymology, Academy of Medical Sciences of the USSR. Oncologic Scientific Center, Academy of Medical Sciences of the USSR, Moscow. Presented by Academician of the Academy of Medical Sciences of the USSR S. S. Debov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 89, No. 2, pp. 168–170, February, 1980.     

Fluorimetric determination of histamine and serotonin in mast cells of normal and germfree rats treated with reserpine and cyclic AMP

The content of histamine (by the reaction with orthophthalic aldehyde) and serotonin (by Falk's reaction) in mesenteric mast cells of normal and germfree rats was determined microspectrometrically. Reserpine (10 mg/kg, intramuscularly) was shown not to change the histamine content, whereas the serotonin content was reduced by 50%. Injection of cyclic AMP (3.5 mg/kg, intraperitoneally) caused the serotonin content to be increased by 80% and the histamine content by 280–320%.Institute of General Pathology and Pathological Physiology, Academy of Medical Sciences of the USSR. Research Laboratory of Experimental Biological Models, Academy of Medical Sciences of the USSR, Moscow. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny. Vol. 83, No. 2, pp. 175–177, February, 1977.     

Experimental production and rearing of germfree miniature piglets for medical and biological research

A method of obtaining and rearing germfree miniature piglets for medical and biological research is described. The germfree animals were reared in strict isolators made from transparent plastic until the age of 3 months. They were fed on a milk diet with the addition of vitamins and salt. They gained in weight satisfactorily throughout the period of observation.Research Laboratory of Experimental Biological Models, Academy of Medical Sciences of the USSR, Moscow Region. (Presented by Academician of the Academy of Medical Sciences of the USSR S. S. Debov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 85, No. 2, pp. 249–252, February, 1978.     

Changes in deoxyribonuclease I inhibitor in mouse spleen after injection of a synthetic polyanion

The synthetic polyanion pyran (a copolymer of divinyl ether and maleic anhydride), if injected into mice, raises the antibody titer against sheep's red blood cells and also activity of serum DNase I and splenic inhibitor of DNase I. At the same time, the weight of the spleen increases. The possible role of the DNase I-inhibitor system in mechanisms of the adjuvant action of the synthetic polyanion is discussed.Research Laboratory of Experimental Immunobiology, Academy of Medical Sciences of the USSR, Moscow. Institute of Medical Radiology, Academy of Medical Sciences of the USSR, Obninsk. (Presented by Academician of the Academy of Medical Sciences of the USSR R. V. Petrov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 12, pp. 678–680, December, 1979.     

Body temperature and response to pyrogenal in germfree and ordinary animals

The body temperature and response to pyrogenal were studied in germfree and ordinary mice and miniature piglets. The body temperature of intact germfree mice and miniature piglets was found to be below that of ordinary animals of the same species. After intraperitoneal injection of pyrogenal (10 minimal pyrogenic doses) into mice and intramuscular injection of pyrogenal into piglets (500 minimal pyrogenic doses) the absence of a marked febrile reaction was observed in the germfree animals. The results point to the important role of the autoflora in the development of the ability of the animal to produce a temperature reaction and fever.Research Laboratory of Experimental Biological Models, Academy of Medical Sciences of the USSR, Moscow Region. (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. 85, No. 3, pp. 263–264, March, 1978.     

Pathways of penetration ofEscherichia coli 055 through the intestinal wall in germfree and ordinary animals

Permeability of the intestinal barrier in germfree animals for bacteria of the enteropathogenic strainEscherichia coli 055 was studied. Germfree and ordinary rats and guinea pigs were used. During the first 24 h after peroral infection withE. coli 055 an increase in the bacteriemia was observed in the germfree animals, whereas in the ordinary animals the bacteriemia was transient in character. Electron-microscopic investigation of the intestinal mucosa of the germfree animals revealed disturbances of intercellular contacts and the formation of spaces containing numerous microorganisms between the enterocytes. In the germfree animals more marked changes also were found in the microvessels of the mucosa. In ordinary animals ingestion and digestion of theE. coli cells by enterocytes and leukocytes was observed. Disturbances of the intestinal barrier discovered in the germfree animals explain the increased bacteriemia in these animals in the absence of a microflora. The results point to the important role of the microbial factor in the formation of the intestinal barrier.Institute of General Pathology and Pathological Physiology, Academy of Medical Sciences of the USSR. Research Laboratory of Experimental Biological Models, Academy of Medical Sciences of the USSR, Moscow. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 85, No. 6, pp. 654–657, June, 1978.     

Cyclic AMP formation during phagocytosis

The content of cyclic adenosine-3, 5-monophosphate (AMP) in phagocytic macrophages was shown to be increased especially during phagocytosis of the living microbes. The cyclic AMP formed during phagocytosis could be detected in the incubation medium, but in the cells it remained at almost the same level. The cyclic AMP concentration in cells of the intestinal mucosa and in the blood serum of germfree guinea pigs also was increased after injection ofEscherichia coli 055 cells; this points to the participation of the adenylate cyclase system in interaction between microorganisms and the epithelium of the small intestine.Research Laboratory of Experimental Biological Models, Academy of Medical Sciences of the USSR. 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. 82, No. 8, pp. 953–956, August, 1976.     

Role of the adhesive lymphocyte population in areactivity to hepatoma 22a

The role of the adhesive fraction of T lymphocytes in areactivity of mice to hepatoma 22a was studied. Experiments showed that removal of the adhesive fraction from a suspension of spleen cells enriched with T lymphocytes potentiates cellular immunity in mice tolerant to hepatoma.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. 88, No. 9, pp. 336–338, September, 1979.     

Effect of azathioprene on DNA synthesis,mitotic activity,and hypertrophy of cells in the regenerating liver and intact spleen of rats

Two-thirds of the liver was removed from August rats, and a suspension of azathioprene in 1% carboxymethylcellulose was injected in a dose of 40 mg/kg. The level of DNA synthesis was determined after 22, 48, 72 h with the aid of thymidine-H³, and the mitotic activity and the dimensions of the cells and their nuclei, were determined in the regenerating liver and intact spleen. Injection of azathioprene led to a decrease in the number of DNA-synthesizing cells in the regenerating liver, and spleen and depressed mitotic activity of the hepatocytes. Considerable development of hypertrophy of the cells and nuclei under the influence of azathioprene also were observed in the hepatocytes of the regenerating liver and the small lymphocytes of the white pulp of the spleen, i.e., the weight of the regenerating liver of the rats receiving azathioprene was restored by hypertrophy as well as mitotic division of the cells.Laboratory of Growth and Development, 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. 78, No. 11, pp. 102–105, November, 1974.     

Possible role of DN-ase I in the development of experimental leukemia

Increased activity of serum DNase I and of splenic inhibitor of DNase I was found during the development of Friend's virus leukemia. Increased activity of inhibitor in the spleen also was discovered after intravenous injection of exogenous DNase I into mice. The possible role of serum DNase I in the development of experimental leukemia is discussed.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. 88, No. 10, pp. 439–441, October, 1979.     

Morphofunctional characteristics of pacemaker formations in the atrioventricular valves of the heart

Multicellular formations responsible for the generation of spontaneous pacemaker activity were found in the cusps of the atrioventricular valves of the rabbit heart by means of a microelectrode technique and electron microscopy. Cells of different morphological structure were found: P cells, cells of the Purkinje type, and transitional cells. These formations were found to have a rich innervation, mainly cholinergic in nature. Definite correlation was found between the morphological structure and electrophysiological parameters of these cells.Laboratory of Experimental Cardiology, P. K. Anokhin Institute of Normal Physiology, Academy of Medical Sciences of the USSR. Laboratory of Electron Microscopy, Central Research Laboratory, I. M. Sechenov First Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR A. M. Chernukh.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 5, pp. 600–604, May, 1977.     

Mineralization of ground substance of new bone tissue in mouse marrow organ cultures

Laboratory of Immunomorphology, N. F. Gamaleya Research Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR, Moscow. Laboratory of Medical Biophysics, Institute of Chemical Physics, Academy of Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR S. V. Prozorovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 106, No. 11, pp. 614–616, November, 1988.     

Comparative study of Ca,Mg-dependent endonuclease in cell nuclei by the use of monoclonal antibodies

Laboratory of Enzymes of Nucleic Acid Metabolism, Research Institute of Medical Enzymology, Academy of Medical Sciences of the USSR. Laboratory of Human Immunogenetics, Research Institute of Medical Genetics, Academy of Medical Sciences of the USSR, Moscow. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 105, No. 4, pp. 419–421, April, 1988.     

Morphological and functional changes in the immune system during reparative regeneration of the liver

During reparative regeneration in the liver functional activity of the immune system is increased. Resection of the liver is accompanied by sharp changes in the structure of the thymus and spleen. The thymus-dependent parts of the spleen are particularly reactive. Resection of the liver in rats is accompanied by an increase in the number of stem cells in the bone marrow, as determined by the splenic colonies method. The number of colony-forming cells in the spleen of recipients of lymphocytes taken from the hepatectomized animals is significantly greater than in the spleen of recipients of lymphocytes from intact rats. If the limb is screened, ability to form endogenous colonies also is increased in partially hepatectomized rats compared with intact animals. Resection of the liver in rabbits is accompanied by a significant increase in immunological reactivity on the first to third days after the operation. The reactions of leukergia and leukocytolysis are sharply intensified during this period.Department of General Biology and Central Research Laboratory, S. M. Kirov Gor'kii 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. 10, pp. 480–484, October, 1977.     

Parental resistance of irradiated mice to (CBA×M523) F1 lymphocytes. fate of transplanted cells,duration of resistance,and its specificity

The immunologic resistance of (CBA x M523)F₁ mouse lymphocytes to a foreign antigen (sheep's red blood cells) in lethally irradiated CBA mice was investigated. If irradiation, transplantation of the cells, and the test injection of antigen were carried out on the same day, the activity of the graft was inhibited (compared with a syngeneic system); if the interval between these operations was increased to 3 days the activity of the donor's cells was restored. Retransplantation of recipients' spleen cells into irradiated CBA and F₁ mice showed the viability of the transplanted cells and absence of their readaptation to the nonsyngeneic microenvironment. The resistance of the recipients could be specifically overcome by previous injection of cells from F₁ mice in combination with or without cyclophosphamide. It can be concluded from the results that genetic parental resistance of CBA mice to cells of F₁ mice is due to the recipient's immunologically competent cells, which are inactivated 3 days after irradiation. They have no cytotoxic action on the donor's cells but temporarily restrict their activity.N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR. Research Laboratory of Experimental Biological Models, 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. 87, No. 5, pp. 441–444, May, 1979.     

Barrier-fixing function in germfree animals

The state of, the barrier-fixing function was studied in germfree and ordinary guinea pigs and rats. After contamination withEscherichia coli 055 (in doses of 5·10⁸ and 10·10¹⁰ bacterial cells for subcutaneous and oral administration, respectively) only transient bacteriemia was observed in the ordinary animals in the early stages after infection. Meanwhile the bacteriemia in the germfree animals increased progressively to cause death of the animals in the course of 2–3 days. A reduced fixing and bactericidal power of the regional lymphatic system and of the deep structures of the monocytic-phagocytic system was discovered in the germfree animals. Experimental confirmation of the role of antibodies in the manifestation of the barrier-fixing function was obtained with respect toE. coli. The experiments show the important role of the microbial facotr in the formation of the barrier-fixing function of the body.Research Laboratory of Experimental Biological Models, Academy of Medical Sciences of the USSR, Moscow Region. (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. 83, No. 6, pp. 706–709, June, 1977.     

Antibody-forming cells of the rat spleen after injury to the midbrain

The number of plaque-forming cells (PFC) in the spleen of rats immunized with sheep's red blood cells (SRBC) after injury to the anterior or posterior part of the medial hypothalamus and also of the thalamus did not differ significantly from the number of PFC in the spleen of intact animals. The titers of hemolyzing and hemagglutinating antibodies in the animals with injuries to the midbrain were a little lower than in intact rats. The decrease in the quantity of circulating antibodies was not connected with the location of the foci of injury but was evidently a consequence of the craniocerebral trauma.Allergologic Research Laboratory, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. D. Ado.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 85, No. 2, pp. 185–187, February, 1978.     

State of nonspecific resistance in germfree and Escherichia coli contaminated miniature piglets

The phagocytic activity of the leukocytes and the serum complement, properdin, and lysozyme levels were studied in germfree miniature piglets and similar animals ocntaiminated withEscherichia coli 055 andE. coli 083. In the presence of autologous serum and complement phagocytosis ofE. coli 055 cells was inhibited, but it was considerably intensified under the influence of specific opsonins (antibodies againstE. coli 055). Lowered levels of complement, properdin, and lysozyme were found in the germfree animals. After peroral monocontamination withE. coli the formation of properdin and complement was stimulated the most, and that of lysozyme the least. Antibodies againstE. coli 055 were not found in the monocontaminated piglets. The highest lysozyme levels were found in the previously germfree animals, which points to the role of other contamination factors thanE. coli cells in the stimulation of lysozyme. It is concluded that microbial contamination plays an important role in the development of the cellular and humoral factors of resistance.Research Laboratory of Experimental Biological Models, Academy of Sciences of the USSR, Moscow Region. (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. 9, pp. 341–344, September, 1978.