Effect of cholinergic agents on survival of mice after acute microwave irradiation

Administration of cholinomimetics (pilocarpine, neostigmine, cytisine) immediately after microwave irradiation (62±5 mW/cm², =12.5 cm, 15–16 min) increased the survival rate of the irradiated mice by 1.2–1.3 times; after administration of cholinolytics fewer of the irradiated mice survived.Vladivostok Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Zakusov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 3, pp. 285–286, March, 1976.     

Mast cells and eosinophilic leukocytes in the formation of mammary gland tumors in female rats irradiated with γ rays at the age of 4 weeks

The onset of mammary gland tumors in female rats receiving a single dose of whole-body irradiation with rays in a dose of 200 R at the age of 4 weeks was studied. The first tumors were found in animals killed 6 months after irradiation, compared with at the 15th month after the beginning of the experiment in the control. All tumors found during the experiment in both irradiated and control rats were benign. Counting the mast cells and eosinophils in the mammary gland tissue showed a disturbance of the dynamics of the eosinophil content and a change in the mast-cell response during the course of radiation tumorigenesis.Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR P. D. Gorizontov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 7, pp. 84–86, July, 1977.     

Model of bicarbonate secretion by resting frog stomach fundus mucosa I. Transepithelial measurements

In the present in vitro experiments on gastric fundus mucosa of Rana esculenta we try to define the mechanism of alkaline secretion that is observed in summer frogs in the resting stomach (blockage of HCl secretion by ranitidine, 10^–5 mol/l). The transepithelial voltage and the rate of alkalinization (ASR) of an unbuffered gastric lumen perfusate was measured as a function of serosal (and mucosal) fluid composition. ASR was high (0.88±S.E. 0.09 Eq·cm^–2·h^–1, n=11) during serosal bath perfusion with HCO₃ ^–-Ringer solution, decreased slightly to 0.50±0.07 Eq·cm^–2·h^–1 (n=6) in HCO₃ ^–-free HEPES-buffered Ringer solution of the same pH, and decreased to approximately 20% when carbonic anhydrase was inhibited by acetazolamide. While replacement of mucosal or serosal Cl^– did not — within 1 h — significantly alter ASR, replacement of serosal Na⁺ in the presence or absence of HCO₃ ^– strongly reduced ASR, and a similar reduction was observed after serosal application of the anion transport inhibitor DIDS (4,4-diisomiocyanatostilbene-2,2-disulphonate, 2·10^–4 mol/l), the metabolic poison rotenone (10^–5 mol/l), the uncoupler dinitrophenol (10^–4 mol/l), and the Na⁺ pump inhibitor ouabain (10^–4 mol/l), while serosal amiloride (10^–4 mol/l) had no effect. These data can be accounted for by a model of alkaline secretion that consists of basolateral HCO₃ ^– uptake from the serosal fluid into the cell via a DIDS-inhibitable Na⁺(HCO₃ ^–)_n-cotransporter and HCO₃ ^– secretion from the cell to the gastric lumen via an anionic conductance pathway. Microelectrode experiments on oxyntopeptic cells reported in the subsequent paper suggest that these cells may also be involved in the resting state alkaline secretion.     

State of the surface activity of rat lung surfactant at various times after left-sided pneumonectomy

The surface activity of seven successive washings from the right lung, determined with the aid of a modified Wilhelmy balance, was the same as in the control until the 5th day after removal of the left lung and also in the late stage after the operation (_min = 23–24 dynes/cm). Intracellular edema of the components on the air-blood barrier and the escape of edema fluid into the lumen of the alveoli of the vesicles were not reflected in the surface-active properties of the lung surfactant. A sharp increase in size of the alveoli on the 5th–7th day after the operation was accompanied by an increase in the surface-active properties of the lung washing (_min = 11–15 dynes/cm) and by increased secretion of material of the osmiophilic lamellar bodies from the type II alveolar cells into the lumen of the alveoli. The cytological mechanisms of the increased production of surfactants in the hypertrophied alveoli are activation of lipid synthesis in the type II alveolar cells, hypertrophy of those cells, and the appearance of binuclear cells.Laboratory of Growth and Development, Research Institute of Human Morphology, Academy of Medical Sciences of the USSR. Laboratory of Physiology, A. V. Vishnevskii Institute of Surgery, 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. 169–172, February, 1977.     

Comparison of compensatory hypertrophy of the kidney after unilateral nephrectomy on adult and senile rats

One kidney was removed from rats weighing 35–900 g. The animals were killed 2, 14, 30, and 60 days after the operation. The degree of compensatory hypertrophy of the remaining kidney varied considerably in the animals of different ages, although it was not reduced in old age. The weight of the hypertrophied kidney of the old rats 60 days after the operation was 55–92% of the combined weight of both kidneys in the control. Hypertrophy of the kidney at all ages was accompanied by increased proliferation of cells of the tubules, especially the proximal tubules. An increase in the size of the renal corpuscles during hypertrophy of the kidney was characteristic of rats of both age groups. However, with an increase in age this process developed faster and was more pronounced. At all times of investigation the hypertrophied kidney of rats of both ages contained 1. 5–2 times more open renal glomeruli than the kidney of the intact animal.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. 82, No. 11, pp. 1394–1397, November, 1976.     

Transgenosis with the participation of plasmid RP1: Indication of the presence of a “composite plasmid” in an intergeneric hybrid ofEscherichia coli

One of the transconjugants (1–7) previously obtained by the writers by conjugation ofEscherichia coli J-62 withPseudomonas aeruginosa 1822, in addition to plasmid RP1 had acquired the ability to grow without proline and tryptophan. A careful study showed that during conjugation of the transconjugant 1–7 with various strains ofE. coli the plasmid RP1 and the chromosomal genes are transmitted together, whereas during transduction with the aid of bacteriophage P1 they are transmitted independently; fertility is found only in transductants carrying the plasmid RP1. The results of these experiments suggest that during intergeneric conjugation chromosomal genes can be transferred even without any firm link with the plasmid (as in the case of composite plasmids). Corresponding fragments of the chromosome ofPs. aeruginosa in cells ofE. coli evidently form small nontransmissible replicons.Laboratory of Extrachromosomal Inheritance, All-Union Research Institute of Protein Biosynthesis. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 9, pp. 360–362, September, 1977.     

The irradiation ofBabesia bovis

Babesia bovis parasites attenuated by 35 krads irradiation and parasites not exposed to irradiation, were injected into intact 2-year-old Hereford steers. All five animals receiving non-irradiated blood died but the five animals which received irradiated blood were only mildly affected.Highly significant differences were observed in changes to plasma fibrinogen, serum fibrinogen-like proteins, packed cell volume, partial thromboplastin time, prothrombin time, blood kinins, and plasma kininogen levels in the control animals but non-significant changes in these parameters occurred in the group receiving irradiated blood. Significant changes in the antiplasmin, ₂M, and the antithrombin levels occurred in control cattle but not in the group receiving irradiated blood. Parasite multiplication rates and maximum parasitaemias were similar in both groups. Irradiation reduced the dose of living parasites from 1×10⁸ to 2.5×10³, but this was not the reason for the mild reactions. It was concluded that irradiation had selected an avirulent parasite population.     

Ultrastructure of conjugates of cytolytic T lymphocytes and target cells

Conjugates of target cells and cytolytic T lymphocytes, isolated on the 11th day after alloimmunization, were investigated. Conjugates were formed by small and medium-sized lymphocytes, in the cytoplasm of which mature secretory granules, crystalloid structures, and lipids were found. The lymphocyte was spherical in shape and its area of contact with the target cell did not exceed 5–15%. Cytolysis of the target cells was observed after incubation for 30–60 min. The lymphocyte became flatter, its nucleus became oval in shape, and the area of its contact with the target cell increased. Meanwhile, hypertrophy and a change in the orientation of the Golgi complex were found in the zone of contact with the target cell, fusion of the secretory granules with the lipids and crystalloid structures took place, and immature secretory granules and vacuolar degeneration of the mitochondria appeared. Peeling of the lymphocyte membrane was observed, and structures connected with it and called membranosomes are described. It is suggested that secretory processes are activated in the cytoplasm of cytolytic T lymphocytes during their interaction with target cells.Laboratory of Systemic Blood Diseases, Oncologic Scientific Center, Academy of Medical Sciences of the USSR. Department of Electron Microscopy, 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 V. M. Zhdanov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 85, No. 5, pp. 560–565, May, 1978.     

Changes in the mesenteric microcirculation of rats with acute hypoxic hypoxia

Hypoxia was induced in rats by administration of a gas mixture corresponding to the composition of the atmosphere at an altitude of 6000 m above sea level. Mesenteric arteries and veins measuring from 9 to 43 in diameter were studied. Their diameter and the pressure and velocity of the blood flow in them were measured. The arterial microvessels were dilated in hypoxia. Their diameter was increased by the greatest amount (by 3–5 ) during the first 3–5 min of administration of the gas mixture. The blood pressure and velocity of blood flow in these vessels were reduced throughout the experiment.Department of Normal Physiology, Abu Ali ibn-Sina Tadjik Medical Institute, Dushanbe. (Presented by Academician of the Academy of Medical Sciences of the USSR A. M. Chernukh.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 3, pp. 277–279, March, 1976.     

Action of KCN on intact and refractory platelets

The action of potassium cyanide on ADP-induced aggregation of intact and refractory platelets was investigated. Cyanide (5·10^–4 M) had virtually no effect on the aggregation of intact cells but stimulated aggregation of refractory platelets. The stimulating effect of the inhibitor on aggregation was not connected with liberation of further quantities of ADP from the cells. Differences in the sensitivity of the aggregating power of intact and refractory cells to partial depression of metabolism is discussed in terms of the calcium model of autoregulation of platelet aggregation suggested previously.Research Institute of Child and Adolescent Physiology, Academy of Pedagogic Sciences of the USSR, Moscow. (Presented by Academician V. N. Chernigovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 8, pp. 940–943, August, 1976.     

Adrenosensitive neurons of the myenteric (Auerbach's) plexus

Experiments on the myenteric plexus of isolated strips of the small and large intestines showed the presence of adrenosensitive cells capable of responding to application of different concentrations of adrenalin (A) and noradrenalin (NA) by a distinct increase in firing rate. The greatest effect was obtained with NA; the range of action of which was wider (from 10^–9 to 10^–5 g/ml) than that of A. Addition of phentolamine to the surrounding solution in most cases prevented the appearance of these effects. Besides spontaneously discharging cells, silent neurons with no spontaneous activity also responded to the addition of A and NA. It is suggested that catecholamines may play a direct part in the modulation of processes carried out by neurons in the ganglia of the myenteric plexus.Laboratory of Physiology of the Autonomic Nervous System, I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. (Presented by Academician V. N. Chernigovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 3, pp. 259–261, March, 1977.     

Activation of precursors of T killers of hematopoietic stem cells by thymosine

Lymph node cells from normal CBA mice, from CBACBA syngeneic radiation chimeras, and B mice were incubatedin vitro with fraction 5 of thymosine, and transplanted into sublethally irradiated (CBA x C57BL)F₁ recipients, and the number of endogenous colonies in the recipients' spleen was determined. Thymosine was shown to potentiate the killer activity of lymph node cells of normal CBA mice and of CBACBA syngeneic radiation chimeras, but not of B mice. It is suggested that the target for the action of thymosine is the subpopulation of T₁ lymphocytes.Academician of the Academy of Sciences of the USSR.Institute of Biophysics, Ministry of Health of the USSR, Moscow. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 85, No. 5, pp. 602–605, May, 1978.     

An effective transformation method for Hansenula polymorpha

Summary We have developed a rapid, simple transformation procedure for intact cells of Hansenula polymorpha. It is a modification of the LiAc method and can yield 10⁴–10⁵ transformants/g DNA. The use of stationaryphase cells, a high cell density per plate and a hear pulse at 50°C for 10 min are among major modifications of the original method. We have also found that, within the XhoI-SalI chromosomal fragment of Saccharomyces cerevisae containing the LEU2 gene, a sequence exists which supports autonomous replication of plasmid moleculles in H. polymorpha.     

Character of the receptors of Auerbach's plexus in the stomach and small intestine

Movements of the stomach and small intestine in eight fed dogs with intact vagus nerves were recorded graphically by a balloon method. Subcutaneous injection of a mixture of benzohexonium (0.125–0.5 ml of a 2.5% solution) with atropine (0.125–0.25 ml of a 0.1% solution) or oxyphenonium (0.125–0.25 ml of a 0.1% solution) first inhibits food motor activity and then converts it to periodic. A similar effect after injection of 0.5–1.0 ml of a 0.1% solution of atropine was found in only two dogs and after injection of 1.0 ml of a 0.1% solution of oxyphenonium in only one dog. Since the preservation of periodic contractions after feeding is characteristic of vagotomized dogs, it is concluded that a pharmacological vagotomy was obtained in the animals studied. It was postulated that the number of muscarinic receptors on cells of Auerbach's plexus exceeds the number of nicotinic receptors.Department of Pharmacology and Experimental Pathology of the Digestive Apparatus, Institute of Physiology, T. G. Shevchenko Kiev University. (Presented by Academician of the Academy of Medical Sciences of the USSR, V. N. Chernigovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 9, pp. 316–319, September, 1977.     

Posthypoxic changes in the cerebral cortex of dogs in the late recovery period after hypovolemic hypotension for 4 hours

On the 14th–21st day of the recovery period after hypovolemic hypotension lasting 4 h the total RNA level in the tissue of the gray matter of the brain fell by 20.9% and the DNA level by 13%. In the postmitochondrial supernatant the concentration of prealbumins fell by 26.5%, of -globulins by 19.2%, and of -globulins by 59.8%; the concentration of albumins and -globulins increased by 12.6 and 50% respectively. Activity of acid cathepsins rose by 50% and of acid phosphatase by 44%. Activity of total lactate dehydrogenase (LD) and glutamate dehydrogenase did not differ significantly from the control values. However, the LD isozyme spectrum showed a decrease in LD₃₊₄₊₅ from 31.9 to 14.2%. Analysis of densitograms of electrophoresis in polyacrylamide gel showed changes in the physiocochemical properties of the protein molecules similar to denaturation in nature. The number of Purkinje cells in the cerebellar cortex was 41.3% below the control level.Laboratory of Experimental Physiology of Resuscitation, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR V. A. Negovskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 8, pp. 933–936, August, 1976.     

Effect of the factors of space flight on erythropoiesis

After orbital flight for 19–22 days on the satellites Kosmos-605 and Kosmos-782 erythropoiesis of rats was inhibited and the morphology of their megakaryocytes was modified. These changes disappeared by the 25th–27th day after the flight.Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 2, pp. 238–240, February, 1977.     

Morphological study of the hearts of rats carried on board biosatellites

The hearts of rats carried on board the biosatellites Kosmos-605 and Kosmos-782 were studied histologically and histochemically. A long space flight (up to 22 days) did not cause any significant structural or metabolic changes to develop in the heart. The absolute weight of the heart also was unchanged. A transient increase in phosphorylase activity in the myocardium of the rats 10–11 h after the end of the flight was due to stress resulting from exposure to the combination of extremal factors accompanying landing of the satellite.Institute of Medico-Biological Problems, Ministry of Health of the USSR, Moscow. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 83, No. 4, pp. 485–486, April, 1977.     

Clinical,hematologic, and immunologic effects of interleukin-10 in humans

We conducted a double-blind, placebo-controlled study to investigate the safety, pharmacokinetics, and immunological properties of interleukin-10 (IL-10) administration in healthy humans. Volunteers received a single intravenous bolus injection of recombinant human IL-10 (1, 10, or 25g/kg) or placebo. Cytokine production in whole blood and peripheral blood mononuclear cells (PBMC) was assessed before and 3, 6, 24, and 48 hr after the injection. Peak serum concentrations of IL-10 (15±1.1, 208±20.1, and 505±22.3 ng/ml) occurred after 2–5 min for 1, 10, and 25g/kg IL-10, respectively. The terminal-phase half-life was 3.18 hr. A transient leukocytosis (24–63% above baseline) was observed 6 hr after injection, which coincided with a dose-dependent decrease (12–24%) in neutrophil superoxide generation. There was a marked inhibition (60–95%) of endotoxin-induced IL-6 production from whole blood in each group receiving IL-10. Production of IL-8 in endotoxin-stimulated blood was reduced in the 10g/kg group. In PBMC stimulated with phytohemagglutinin and phorbol ester, there was a decrease (72–87%) in interferon- (IFN) production 6 hr after IL-10 with a return to pre-IL-10 levels after 24 hr. This reduction was only partially associated with a decrease in the number of CD2-bearing cells. We conclude that IL-10 administration into humans is without significant side effects, and a single injection reducesex vivo production of IL-6, IL-8, and IFN.     

Importance of the time of bone marrow transplantation for manifestation of allogeneic inhibition of stem cells

The effect of duration of the interval (4–96 h) between irradiation of F₁ (CBA×C57BL/6) hybrids and transplatation of bone marrow from C57BL/6 mice on manifestation of allogeneic inhibition of the stem cells was studied. In this particular donor-recipient model the degree of allogeneic inhibition was 90%. Transplantation of bone marrow carried out 4–48 h after irradiation had no effect on the number of colonies in the spleen of the F₁ hybrids. Considerable abolition of allogeneic inhibition (33%) was observed if the parental cells were injected 96 h after irradiation. Remote transplantation had no effect on the number of colonies in the spleen of syngeneic recipients.Laboratory of Experimental Genetics, 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. 81, No. 3, pp. 347–348, March, 1976.     

Changes in template properties of chromatin during aminoazo-carcinogenesis

Male rats were kept on a diet containing the carcinogen 3-methyl-4-dimethylaminoazobenzene. No difference from the control was found either in the electrophoretic spectrum of the total protein of deoxyribonucleoproteins (DNP) or nonhistone proteins, or in the character of the melting curves of DNA and DNP, or in the template ability of DNA isolated from rat liver. DNP of tumor tissue functioned more actively as template for RNA synthesisin vitro in a system with animal or bacterial RNA-polymerase, with low concentrations of substrates (of the order of 2·10^–5 M), but RNA synthesis did not differ from the control in the presence of high concentrations of each of the substrates (2·10^–3 M). During lysis of the nuclei in a solution with alkaline pH the percentage of activity of RNA-polymerase that could be extracted from the complex with chromatin decreased considerably if the rats were fed with the carcinogen.Laboratory of Biochemistry of Tumors, Institute of Experimental and Clinical Oncology, Academy of Medical Sciences of the USSR, Moscow. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 81, No. 3, pp. 363–365, March, 1976.