Quantitative regularities of development of endogenous infection in irradiated organism (survey of literature)

Statistical analysis of data from the literature and the author's own experimental results was carried out in order to reveal functional dependence between the dose of irradiation and the development of endogenous infection in an irradiated organism. Direct linear dependence was established between the dose of irradiation and the severity of endogenous infection at doses causing death from the "bone-marrow" syndrome in acute radiation sickness. In the case of death from the "intestinal" syndrome, inverse linear dependence can be observed between the dose of irradiation and the culture yield of microbes from internal organs. In this case, the pathological effect on the organism is due to bacterial endotoxins formed during disintegration of microbial cells in the organism. Endogenous infection and endotoxinaemia essentially aggravate the course of acute radiation disease. The importance of endogenous infection in death of the organism is neutralized after irradiation in doses causing death "under the ray".     

Effect of branched-chain amino acids on nitrogen metabolism in irradiated rats

The influence of a mixture of amino acids, with a branched chain, on the protein-nitrogen metabolism in irradiated animals was investigated. Repeated intraperitoneal administrations of the drug was shown to reduce the severity of radiation affection and to normalize nitrogen metabolism decreasing the postirradiation nitrogen losses by the organism.     

Concept of the "physiological age" of animals and its application to ixodid ticks

The definition "physiological age" of animals has been revised. A new definition has been formulated on the basis of V. N. Beklemishev's (1962) and Ju. S. Balashov's (1962) theses as follows: physiological age of animals (= biological) is an extent of general irreversible morphophysiological change of organism during its whole life and determined by the accumulation of irreversible changes as a result of its normal vital activity. This definition is equivalent to that of "biological ages" of man. The contents of this definition is enlarged and the possibility of its use for different animals including their males is unified. On the basis of the general concept this definition is specified in regard to ixodid ticks: physiological age of hungry ixodid tick is an extent of general irreversible morpholophysiological change of its organism during the whole life and determined by the state of reserve nutrient and excretory substances. According to the amount of reserve and excretory substances in the organism of ixodid tick we distinguish 4 main physiological ages: new-born, young, mature and old which reflect general biological regularity of age development of animals.     

Natural resistance against hematopoietic cells in lethally-irradiated mice infected with Friend leukemia virus

Summary The influence of in vivo infection with the polycythemic substrain of Friend leukemia virus on noninducible (natural) resistance against allogeneic normal or malignant grafts was studied in lethally irradiated mice. Parallel studies were performed on the NK system in the same experimental conditions. The results indicate that FLV-P infection of mice with full (DBA/2) vs partial (BALB/c and CD2F1) susceptibility did not suppress their in vivo natural resistance against bone marrow or El-4 leukemia cells. On the other hand, a decline in NK activity paralleled the progression of leukemic disease in the more susceptible DBA/2 hosts. Abbreviations used: FLV-P, N-tropic polycythemic substrain of Friend Leukemia Virus Complex; NR, natural resistance; NR in vivo, natural resistance against normal or malignant hemopoietic grafts occurring in vivo in lethally irradiated mice; NK, natural killer; (¹²⁵I)IUdR, ¹²⁵I-labeled 5-iodio-2-deoxyuridine; IV, intravenous     

The mechanism of unresponsiveness in lymphocytes specifically selected by antigen in normal rats.

The immunological potentialities of populations of thoracic duct lymphocytes collected from rats recently challenged with sheep erythrocytes were compared with those of lymphocytes from rats immunologically tolerant of this antigen. Both "selected" and tolerant populations fail to mount immune responses to sheep erythrocytes in irradiated syngeneic hosts but can do so if transferred to semi-allogeneic recipients. If co-cultivated with normal lymphocytes in irradiated hosts, both types of population can modulate the responsiveness of the former to sheep erythrocytes. Supplementation of normal lymphocytes with "selected" populations collected earlier than 28 hours after challenge of the donors tends to result in augmented responses while later collections are more likely to be associated with suppression. Consequently, it is suggested that "selected" populations are unresponsive because of the presence of specifically activated cells rather than as a result of their depletion. The influence of "selected" populations on the responsiveness of normal lymphocytes is attributed to this content of activated cells.     

Modifying action of Mn(II) chelate with ethyl ester of salicylydene tyrosine on some biophysical parameters of erythrocyte membranes of the irradiated organism

The presentation summarizes the results of studies on radioprotective activity of newly synthesized Mn(II) chelate with ethyl ester of salicylydene D,L-tyrosine, basing on the evaluation of its membrane-protective effects, revealed at different periods post the exposure of the organism to ionizing radiation. It was revealed that the administration of the compound into the animal organism before the radiation exposure (gamma-irradiation of 60Co at a dose level of 4.8 Gy) produced correcting action on structure-functional properties of erythrocyte membrane of irradiated rats: the excessive activation of lipid peroxidation of erythrocyte membranes was inhibited, the passive permeability of erythrocytes for K+ ions was normalized, the deformity and membrane potential of erythrocytes according to hydrogen-chlorine gradient were recovered.     

Postradiation change in the body's reaction to adrenaline

In experiments with albino mongrel rats weighing 220-260 g a study was made of the influence of adrenaline on the cyclic nucleotide content of blood plasma at early times following 60Co-gamma-irradiation (75 Gy). The absence of the organism response to adrenaline is perhaps due to the development of postirradiation desensitization of beta-adrenergic system and inability to induce cAMP formation in a cell. The data are submitted confirming the influence of levamisole on the cyclic nucleotide level. The level of cGMP decreased in thymocytes and increased in blood plasma after the administration of the drug to irradiated animals.     

Aldolase biosynthesis and stability in a monolayer of intact and irradiated rat liver cells

Aldolase turnover in rat hepatic cell culture and the influence of whole-body X-irradiation on the rates of synthesis and degradation of the enzyme and its "half-life" have been investigated. Aldolase biosynthesis in irradiated cells increases significantly as the rate of its degradation grows and the time of its functioning decreases.     

Interhemisphere Asymmetry of the Pro-/Antioxidant Systems in the Rat Brain: Effects of Hypokinesia and Extrahigh-Frequency Electromagnetic Radiation

We studied changes in the interhemisphere asymmetry of the intensity of lipid peroxidation (LPO) and total content of thiol groups (TTG) in the rat cerebral neocortex. These indices characteristic for animals with different motor phenotypes (dextrals, sinistrals, and ambidextrals) were measured in the control and under the influence of hypokinesia, low-intensity millimeter-range electromagnetic radiation (mmR EMR), and their combination. The development of hypokinetic stress in rats (after 10-day-long motor restriction) resulted in a sharp activation of LPO and suppression of thiol/disulfide metabolism in the neocortex of rats with different types of motor asymmetry. Hypokinesia was accompanied by considerable drops in the coefficients of interhemisphere asymmetry (up to reversal of their signs); this can be related to decreases in the resistivity of the organism to stress and adaptability to external influences. When intact animals with different types of motor asymmetry were irradiated with mmR EMR, the intensity of LPO in the neocortex of both hemispheres decreased concurrently with intensification of thiol/ disulfide metabolism. The combined influence of hypokinesia and mmR EMR led to considerably smaller shifts in the above indices, as compared with those after isolated action of hypokinesia. When mmR EMR influenced animals were kept under conditions of normal motor mode and motor restriction, the signs of the coefficients of asymmetry of the indices under study did not change, while the intensity of interhemisphere asymmetry increased. We suppose that this is related to an increase in the adaptability of the organism to the action of stressor factors.     

Studies of delayed hypersensitivity to L. Monocytogenes in mice: nature of cells involved in passive transfers

C3Hf/Umc mice were immunized by an intravenous injection of a sublethal dose of live Listeria monocytogenes. The animals developed delayed-type hypersensitivity (DH) concomitant with infectious immunity to this organism. Delayed hypersensitivity could be transferred to normal lethally irradiated mice with spleen cells from immune animals. The immune cells cells responsible for transfer of adoptive immunity were susceptible to in vitro cytolytic action of anti-theta iso-antibody and complement, since such treatment rendered these cells incapable of further passive transfer of specific immunity to Listeria. The acquired DH to Listeria persisted in mice after 900 R lethal irradiation, provided normal syngeneic bone marrow cells were also administered, thus indicating the persistance of a cell population in the immune irradiated mice, resistant to effects of radiation. The radio resistant nature of this immune cell population was further demonstrated by passive transfer with spleen cells, derived from preimmunized lethally irradiated mice to normal syngeneic mice or to lethally irradiated nonimmunized hosts reconstituted with normal bone marrow which then responded to antigenic challenge with DH.Treatment of the immune radio resistant spleen cells in vitro with anti-theta and complement eliminated passive transfers of DH by these cells; however, this effect was less obvious than similar treatment of the immune, nonirradiated, spleen cells.     

Role of M2b macrophages in the acceleration of bacterial translocation and subsequent sepsis in mice exposed to whole body [137Cs] γ-irradiation

The influence of whole-body gamma-irradiation on the antibacterial host defense against Enterococcus faecalis translocation was investigated. Mice irradiated with or without 5 Gy [(137)Cs] gamma-rays were orally infected with 10(6) CFU/mouse E. faecalis. The pathogen was detected in the mesenteric lymph nodes (MLNs) of irradiated mice 1-4 d postinfection, whereas E. faecalis was not isolated from MLNs of normal mice. All irradiated mice died within 5 d of infection, whereas no mortality was shown in normal mice infected with the pathogen. Irradiated mice inoculated with normal mouse MLN macrophages (M) were shown to be resistant against the infection, although the same mice inoculated with irradiated mouse MLNM (I-MLNM) died postinfection. I-MLNM were identified as IL-10(+)IL-12(-)CCL1(+)LIGHT(+) M (M2bM) and were shown to be inhibitory on M conversion from resident M to IL-10(-)IL-12(+)M (M1M). M2bM were demonstrated in MLNs of mice 10-35 d after gamma-irradiation. M1M were not induced by E. faecalis Ag in cultures of I-MLNM, whereas normal mouse MLNM were converted to M1M in response to the Ag stimulation. After treatment with CCL1 antisense oligodeoxynucleotides, M2bM disappeared in MLNs of irradiated mice, and M1M were generated in MLNs of these mice following E. faecalis stimulation. These results indicate that M2bM presented in the I-MLNM populations were responsible for the impaired resistance of mice irradiated with gamma-rays to bacterial translocation and subsequent sepsis. E. faecalis translocation and subsequent sepsis may be controlled immunologically by the intervention of M2bM present in MLNs.     

Modifications of Motor Asymmetry in Rats under the Influence of Low-Intensity Extra High-Frequency Electromagnetic Radiation in the Norm and under Stress Conditions

We studied modifications of motor asymmetry in rats with different motor lateralization (dextrals, sinistrals, and ambidextrals) induced by low-intensity extra high-frequency (EHF) electromagnetic radiation (EMR), hypokinetic stress, and their combination. It was found that the development of hypokinetic stress in rats induced by limitation of their mobility results in a considerable decrease of the coefficient of motor asymmetry (up to inversion of its sign); this can be related to a decrease in the resistivity to stressing and adaptability of the organism to the influence of external factors. The influence of EHF EMR on the animals under conditions of both normal and limited motor activity resulted in an increase in the index of motor lateralization in animals of all phenotypic groups under study; probably, this helped to increase the adaptive capabilities of the organism. Neirofiziologiya/Neurophysiology, Vol. 37, No. 2, pp. 164–168, March–April, 2005.     

Physiological responses of the hyperthermophilic archaeon "Pyrococcus abyssi" to DNA damage caused by ionizing radiation

The mechanisms by which hyperthermophilic Archaea, such as "Pyrococcus abyssi" and Pyrococcus furiosus, survive high doses of ionizing gamma irradiation are not thoroughly elucidated. Following gamma-ray irradiation at 2,500 Gy, the restoration of "P. abyssi" chromosomes took place within chromosome fragmentation. DNA synthesis in irradiated "P. abyssi" cells during the DNA repair phase was inhibited in comparison to nonirradiated control cultures, suggesting that DNA damage causes a replication block in this organism. We also found evidence for transient export of damaged DNA out of irradiated "P. abyssi" cells prior to a restart of chromosomal DNA synthesis. Our cell fractionation assays further suggest that "P. abyssi" contains a highly efficient DNA repair system which is continuously ready to repair the DNA damage caused by high temperature and/or ionizing radiation.     

Effect of a neutrophilia-inducing tumor on hemopoietic stem cells in mice

The influence of neutrophilic stimulation on hemopoietic stem cells was studied in mice with tumor-induced neutrophilia. Transfusions of marrow cells from normal and neutrophilic tumor-bearing mice into lethally irradiated normal and tumor-bearing mice were performed. The number and the erythroid:granuloid (E:G) ratio of day 7 colonies in the recipient spleens and bones as well as the size of spleen colonies of recipient animals were determined. The E:G ratio of spleen and bone marrow colonies between normal and tumor-bearing mouse recipients and the number of spleen colonies did not differ significantly in either experiment. However, spleen colonies which developed in tumor-bearing irradiated mice were significantly larger than those which developed in normal recipients in both experiments. These studies indicated that while the line of differentiation taken by hemopoietic stem cells was not affected by the neutrophilic influence of the tumor, the tumor-bearing host environment appeared to enhance proliferation of transfused stem cells and/or their descendants. The stimulators of granulocytopoiesis in this model of neutrophilia appear to act on a population of progenitor cells more mature than the stem cells capable of forming 7-day colonies in the spleen and bone marrow of irradiated recipient mice.     

Effects of extreme factors and antioxidant alpha-tocopherol on the intensity of blood plasma chemiluminescence]

It was established in experiments on rats that intensity of "fast flash" of iron-induced chemiluminescence of biological samples containing microvolumes of blood plasma correlate with resistance of organism to severe hypoxia. The new method is promising for the estimation of the sensitivity of intact organism to severe hypoxia, for registration of antioxidant therapy effects and for studying the mechanisms of extreme factors influence on the organism.     

Further attempts to induce “egg transformation” using irradiated pollen

Summary Numerous pollination treatments involving heavily irradiated (40–100 krad) pollen of diverse plant species failed to produce any clear cut egg transformants of the type reported by Pandey in Nicotiana. Genetic stocks of pea, rapeseed, and apple, bearing multiple Mendelian markers, were employed to detect any possible transformation events. For each plant species, an optimal level of irradiation was determined which would allow normal pollen tube growth leading to fertilization, but which would prevent the formation of normal hybrids due to the pulverized condition of the chromosomes contributed by the irradiated pollen. Pollination treatments included selfing, pollination with donor pollen mixed with self pollen, pollination with irradiated donor pollen mixed with self pollen, pollination with irradiated pollen followed by a delayed self pollination, and pollination with irradiated pollen by itself. None of these treatments produced clearly transformed seedlings. The total number of potential transformation events screened was in excess of 6,046 including 2,268 for pea, 3,309 for rapeseed, and 469 for apple. It is concluded that if egg transformation occurs outside of Nicotiana it is a rare event, and its frequent occurrence in Nicotiana must be, at best, an isolated phenomenon.Approved by the Director of the New York State Agricultural Experiment Station for publication as Journal Paper No. 3557     

The chemiluminescence reactions of the blood neutrophils and of peritoneal exudate cells in Syrian hamsters to the intraperitoneal administration of cellular and microbial materials]

The luminol-dependent chemiluminescence (CL) activity of peritoneal exudate cells and blood neutrophils of Syrian hamsters inoculated intraperitoneally with heat-inactivated microbial particles of Candida albicans, (C. albicans), heated irradiated normal cells and native or heated irradiated malignant tumor cells was studied. The inoculation with particles of C. albicans and heated normal cells induced significant activation of CL of peritoneal exudate cells, but did not influence the CL reaction of blood neutrophils. The inoculation of animals with nonheated irradiated tumor cells led to increase of CL response of both peritoneal exudate cells and blood neutrophils. The inoculation with heated irradiated tumor cells did not activate CL of peritoneal exudate cells and led to slight, but long-lasting decrease of CL response of blood neutrophils.     

Radioprotective action of a combination of poly I-poly C and mexamine

In experiments on (CBA X C57Bl)F1 mice irradiated with doses of 8-12 Gy a study was made of the effect of a mixture of polyI-polyC (2.5 mg/kg, 2 days before irradiation) and mexamine (30 mg/kg, 5 min before irradiation) on the survival rate of animals and the times of their death. It was shown that polyI-polyC potentiates the protective effect of mexamine not increasing its toxicity. The protective agents used in a combination decrease the "intestinal" death of irradiated animals while used separately fail to produce this effect.     

A quantitative validation of the patterns determining the changes in higher nervous activity after irradiation with heavy charged particles under conditions of the influence of stress factors

The major regularities that govern the alteration of the higher nervous activities after irradiation with heavy charged particles have been grounded quantitatively. The influence of the environmental factors on the exposed organism acquires a stress nature and is accompanied by the alteration of the central-central and central-peripheric relationships in major nervous processes whose pathogenesis is determined, to some extent, by a change in the homeostatic level of the synaptic energy transfer rate that depends quantitatively on the response of the irradiated organism at different stages of the development of radiation damage. The rate of the synaptic transfer at early periods of radiation damage development is 11.6, 9.7, and 12.4 (relative units) corresponding to the stages of radiation affection by heavy charged particles which permits to compare qualitatively and quantitatively the reactions of final acceptors of various executive morphofunctional structures after irradiation with heavy charged particles.