The yield of visible mutations, spontaneous and N-nitroso-N-ethylurea-induced, in the Drosophila mei-9 11 strain defective for excision repair

The increase of spontaneous and induced frequencies in mature sperm by N-nitroso-N-ethylurea visible mutation in the stock mei-9(11) of Drosophila melanogaster blocking the excision reparation has been shown. It is suggested that the mutation mei-9(11) blocks the correct way of reparation that is shown in mutator effect of this mutation.     

Electron microscopic study on the gel of the central part of the corpus vitreum in the ox

Summary The central part of the corpus vitreum in the ox possesses a relative firmness. Electron microscopically it has been shown to consist of collagen fibrils with interfibrillar spaces containing 8 nm thick granules. The granules are made up of chains of macromolecules (hyaluronic acid in an oligomer state) 130–200 nm in length and of an oval shape. The collagen fibrils are tightly covered with 8.5 nm thick macromolecules which represent highly polymerized hyaluronic acid. These macromolecules can be stained with ruthenium-red.Dedicated to Prof. Dr. med. Drs. h.c. W. Bargmann, Kiel, on the occasion of his 70th birthday     

The DD2R gene expression level in the corpus allatum affects the fitness of female Drosophila melanogaster

The effect of tissue-specific suppression of the dopamine D2-like receptor gene (DD2R) in the corpus allatum (CA), the gland that synthesizes juvenile hormone (JH) on the Drosophila melanogaster resistance to heat stress has been studied. A decreased expression of the DD2R gene in the CA has been found to substantially decrease the heat stress resistance of adult transgenic female, but not male, D. melanogaster compared to the control group, this phenomenon being weakly pronounced in juvenile flies. The effect of DD2R activation on the D. melanogaster reproductive function has been estimated. It has been shown that treatment of D. melanogaster with a synthetic specific agonist of DD2R decreases the fertility, the effect being considerably stronger in adult flies than in juvenile ones. It is concluded that the change in the number of DD2Rs in CA or their activation decreases the fitness of Drosophila.     

The influence of mesenchymal stem cell transplantation time on myocardial reparation in rat experimental heart failure

Mesenchymal stem cells (MSCs) have an ability to migrate in the organism to injured tissue to exert influence on inflammation and reparation in these regions. The aim of this study was to determine the optimal time of MSCs transplantation for myocardial reparation in rat experimental heart failure. The experiments were carried out on inbred line Wistar-Kyoto rats. Myocardial experimental infarction (EI) was induced by ligation of the left descending coronary artery. MSCs were isolated from bone marrow, cultivated in vitro and injected into the tail vein on the day of experimental infarction operation. It was shown that the time of MSCs transplantation exerted an essential influence on angiogenesis in a damaged myocardium, on ventricular dilatation and morphological structure of the scar. The best time for MSCs transplantation was determined within two days before EI, and seven days after EI. As a result, the overload of the border zone of infarct region decreased, and no features of infarction relapse were shown in the border zone.     

The role of ADP-ribosylation processes in the repair of cytogenetic damage in mammalian cells

Nicotinamide (NA) was shown to increase the yield of chromosome aberrations in irradiated Chinese hamster cells. The effect was observed with all doses used (1-4 Gy) and in all phases of the cell cycle; it was maximum as cells transferred from S to G1 phase. The modification of radiation-induced aberrations was more pronounced in the chromatid deletions and in exchanges. The combined action of NA and caffeine showed a synergism. It is assumed that NA inhibits reparation in a different way than caffeine does.     

Characteristics of mutagenesis and repair following UV irradiation in the methylotrophic bacterium Pseudomonas methanolica

The methylotrophic bacterium Pseudomonas methanolica was shown to be very resistant to the bactericidal and mutagenic action of UV irradiation. The activity of reparation processes after UV irradiation was also detected as well as a weak photoreactivating activity in P. methanolica. The decrease in the survival rate of irradiated cells under the action of caffeine and acriflavine, reparation inhibitors, is indicative of the activity of the excision reparation systems and, possibly, the recombination branch of postreplicative reparation. No activity of the inducible reparation system was found. It has been concluded that the elevated resistance of P. methanolica cells to the bactericidal and mutagenic action of short-wavelength UV irradiation is associated with the activity of the reparation systems.     

Effect of dibunol and isoptin on the creatine kinase and myoglobin content of the blood serum in dogs undergoing postischemic coronary reperfusion

The effect of an antioxidant dibunol and calcium antagonist verapamil on postperfusion release of myoglobin (Mb) and MB-creatine kinase (MB-CK) has been assessed in 30 dogs with experimental coronary occlusive myocardial infarction. It has been shown that reperfusion after 3-hour ischemia does not only accelerate the release of intracellular proteins, but also leads to pronounced myoglobinemia and blood enzymes. In postischemic blood flow recovery with combined dibunol and verapamil preliminary injections, an almost threefold decrease in MB-CK and Mb blood content, as compared to "reperfusion" indexes, was observed by the 10th minute of reperfusion.     

Effect of interferon-inducing complex on thymidine 3H-labeling of DNA, RNA and proteins of marrow cells after total X-irradiation of mice

Interferonogen is shown to intensify the RNA synthesis only slightly, practically having effect neither on DNA synthesis nor on protein one. Interferonogen administered 2h before irradiation impedes development of the pronounced inhibition of DNA, first of all. Basing on the fact that the mentioned regularities were manifested at the early stages of the post radiation period (up to 3-4 h) and coming from the previously established radioprojection efficiency of interferonogen it is supposed that interferonogenesis takes part in regulation of the cell reparation systems.     

The effect of polypeptides from the thymus, bone marrow and bursa of Fabricius on the immunogenesis and hemostasis in neonatally thymectomized and antenatally bursectomized chickens

The effect of polypeptides from the thymus, bone marrow and bursa of Fabricius on immunogenesis and hemostasis was investigated in neonatally thymectomized and antenatally bursectomized chickens. It has been established that polypeptide factors from the bursa of Fabricius have the most pronounced effect on the immunity and hemostasis.     

Repair of the protein structures of ciliated epithelial cells after heat damage

A study has been made of the ability of ciliated pharengial cells of Rana temporaria L. to repair heat injury. The heat injury estimated by cessation of cellular motile activity has been shown to repair, ciliar movements being renewed. The reparation of the ciliar function is due to the restoration of nativity of the intracellular protein structures providing for the ciliar motility. These structures can be repaired only when they are a component of the whole living cell system; they are not capable of spontaneous renativation, however, when isolated as "glycerinized cell models". It is suggested that the reparation of heat injury in these cells is an active process, presumably dependent on the intracellular metabolism.     

Use of interferon inducers in treating viral diseases

The results obtained in the experimental and clinical study of the preparations of mephenamine acid and levamisole with respect to their interferonogenic and interferon-stimulating action and their therapeutic effectiveness in influenza and virus hepatitis are presented. The study has revealed that mephenamine acid, along with its capacity for stimulating the processes of interferon formation in the body, produces a pronounced curative effect, prevents the development of postinfluenza complications much more effectively than levamisole and remantadin and accelerates the processes of reparation in virus hepatitis.     

The Jolly-Seber model with tag loss

Tag loss in mark-recapture experiments is a violation of one of the Jolly-Seber model assumptions. It causes bias in parameter estimates and has only been dealt with in an ad hoc manner. We develop methodology to estimate tag retention and abundance in double-tagging mark-recapture experiments. We apply this methodology to walleyes (Stizostedion vitreum) in Mille Lacs, Minnesota.     

The action of low-intensity extremely high-freguency electromagnetic radiation on growth parameters for bacteria Enterococcus hirae

It has been found that the exposure of Enterococcus hirae ATCC9790, grown under anaerobic conditions for 30 min or 1 h, to low-intensity (flux capacity 0.06 mW/sm2) coherent electromagnetic radiation (EMI) of extremely high-frequency 45 - 53 GHz), or millimeter waves causes a marked prolongation of the lag-growth phase and a decrease in their specific growth rate, the inhibitory effect increasing in the frequency range from 49 to 53 GHz. The effect enhanced as duration of expocure was encreased from 30 min to 1 h; however, further increase in exposure duration to 2 h did not cause an enhancement of the effect. It has been shown that the action of extremely high-frequency EMI on these bacteria does not depend on medium pH (pH 8.0 or pH 6.0). It is proposed that these bacteria have defensive or reparation mechanisms which compensate for the action of radiation; the occurrence of different mechanisms for pH regulation is not ruled out.     

Effect of an opioid peptide on the healing of experimental myocardial infarct

The effect of an opioid hormone (Leu-enkephalin analog Tyr-Dala-Gly-Phe-Leu-Arg) on the healing of myocardial infarction caused by the ligation of the descending branch of the rabbit left coronary artery has been investigated. The peptide was injected intraperitoneally at a dose of 10 micrograms/kg daily. Using light and electron microscopy, the peptide has been shown to exert a pronounced stimulating effect on the healing of the necrotic zone on days 3 and 7 of the experiment. Opioid peptides are suggested to take part in the healing of various disorders.     

Seasonal differences in the regeneration of planarians under conditions of long-term electromagnetic shielding

It has been found that the regeneration of planarians is most intense in summer and least intense in winter. In spring and autumn, the index of regeneration and the velocity of movement are higher than in winter but lower than in summer. Long-term electromagnetic shielding modifies the intensity of regenerative processes, and this effect is season-dependent. The stimulation is most clearly pronounced in winter and least pronounced in summer and decreases with increasing duration of shielding. In spring, only a tendency to stimulation of regeneration is observed, which increases with the length of the observation terms.     

Seasonal differences in the regeneration of planarians subjected to long-term electromagnetic shielding

It has been found that the regeneration of planarians is most intensive in summer and least intensive in winter. In spring and autumn, the index of regeneration and the velocity of movement are higher than in winter but lower than in summer. Long-term electromagnetic shielding modifies the intensity of regenerative processes, and this effect is season-dependent. The stimulation is most clearly pronounced in winter and least pronounced in sommer and decreases with increasing duration of shielding. In spring, only a tendency to the stimulation of regeration is observed, which increases with the length of the observation period.     

ANTICOAGULANT DRUG TREATMENT OF CORONARY ARTERY DISEASE

Anticoagulant therapy of arteriosclerotic heart disease may prove to be most valuable when applied on a long-term basis for prevention of recurrent myocardial infarction. While its prophylactic value in impending infarction has not been established, at least the accepted treatment for the acute stage is already begun if an anticoagulant has been administered before an inevitable infarction occurs.The chief value of the anticoagulant, though, seems to lie in preventing cardiac mural thrombosis and extracardiac thromboembolism. It is by this effect, apparently, that mortality has been reduced by 50 per cent among survivors of myocardial infarction who receive continuous dicoumarin therapy.While the danger of hemorrhage is still present, it is being steadily reduced by increasing skill in the management of anticoagulant therapy, and for a long time the risk has been far outweighed by the reduction in coronary occlusion.Physicians have a duty to learn the use of anticoagulant therapy, obtain the facilities necessary for it, and apply it to patients who are able and willing to cooperate in prolonging their useful lives.     

The effect of the biochemical adaptations in the Manchu alder (Duschecia fruticosa (Rupr)) to an elevated natural radiation background on the survivability of seedlings and on the radiosensitivity of its seeds

Seeds and sprouts of bushy alder existing for long under the condition of the enhances natural radiation background (ENRB; from 1.4 to 72.0 mCu/(kg.s)) have been examined to determine biochemical adaptations to permanent low-level irradiation. To achieve this goal a combined cytological and biochemical technique for the assessment of the activity of genome of the sprout root meristem in response to translation, replication and reparation has been applied. The activity of antioxidant systems has been studied. The data obtained allow us to reveal mechanisms of alder bush biochemical adaptations to various ENRB rates and their effect upon seeds radiosensitivity and sprouts survival. It is determined that the increase in sprout vitality and high radioresistance of seeds ripened under the conditions of low-level natural radiation is due to the content of low molecular antioxidants and activation of systems of genome reparation.     

Opioid peptide biosynthesis: enzymatic selectivity and regulatory mechanisms

Certain general principles determine the biosynthesis of most biologically active peptides, including the opioid peptides, from large protein precursors. In almost all instances, the active peptide is embedded in the precursor flanked on both sides by pairs of basic amino acids. The first step in processing involves a trypsinlike enzyme, cleaving to the carboxyl terminus of basic amino acids, and leaving the active peptide with a basic amino acid on the carboxyl terminus. A carboxy-peptidase peptidase B-like enzyme then removes the remaining basic amino acid. It has been unclear whether any endopeptidases with trypsinlike activity are selective for one or another basic amino acid. Recently a soluble endopeptidase has been identified that can cleave to both the carboxyl and amino termini of basic amino acids. Enkephalin convertase (carboxypeptidase E, H) (EC 3.4.17.10) has considerable selectivity, and appears to be physiologically associated with the biosynthesis of enkephalin as well as a limited number of other neuropeptides. The turnover of opioid peptides and other neuropeptides is most effectively ascertained by measuring levels of mRNA either biochemically or by in situ hybridization. Striking dynamic alterations include a pronounced increase in levels of proenkephalin mRNA in the corpus striatum after blockade of dopamine receptors, but changes in opioid peptide mRNA after opiate addiction are less clear.