[The protective activity of a new variant of the probiotic Acilact in exposure to ionizing radiation and anticancer chemotherapy under experimental conditions].

The aim of the study was to investigate the protective activity of a new variant of the probiotic Acilact in exposure to ionizing radiation and anticancer chemotherapy under experimental conditions. The study revealed protective effects of the preparation after combined exposure of mice to radiation and temperature. The preparation increased 30-day survival of the mice, inhibited intestinal colonization with gram-negative microorganisms, and increased resistance to LPS. A multidirectional protective effect of the probiotic was observed after the use of sublethal doses of radiation; this effect was manifested by quicker normalization of hematological parameters and bone marrow cellularity, as well as elevation of blood concentration of the hemoragulatory cytokines IL-3 and IL-6.

[The estimation of the nitric oxide role in the aggravation of combined radiation-thermal injuries].

The influence of specific inhibitor of inducible NO synthase S-ethil-isothiourea (as "Difetur" preparation) on liver NO production level, and 30-days survival, mean survival time and probability of mortality within animals under combined radiation/thermal injury (CRTI) were evaluated. Experiments were carrying out on mice (whole body gamma-irradiation at the dose of 7 Gy + 10% body surface full-thickness thermal burn). It was shown, that CRTI induce 2-fold statistical significant increase of NO production in liver of experimental animals. Mice pretreatment with Difetur preparation lead to practically full inhibition of NO production. In the group of animals, with Difetur administration during first two days after CRTI 60% mice survived as compared 15% survive in control group. In pair with data on probability of mortality it was suggested that growth of NO production in the early period of CRTI increase sensitivity of animals to pathological processes leading to death on 10-12 days.

[Some consequences of systemic inflammatory response in the pathogenesis of aggravation of outcomes of combined radiation and thermal injuries].

Experiments were executed on (CBA x C57BL6) F1 male mice. Animals were subjected to the total body irradiation with a dose 7 Gy or combine radiation-thermal injury (CRTI), when irradiated animals were additionally subjected to a thermal burn of 10% of the body surface. Some signs of systemic inflammatory response were investigated in these two compared groups. It was established that the period of substantial increasing of the mortality in animals with CRTI (from 7th till 15th day) was characterized with expressed postradiation leikopenia and thrombocytopenia, was accompanied by hypoalbuminemia and hyperfibrinogenemia with a moderate raise in serum ALT activity. From all investigated hematological and biochemical parameters, at CRTI only plasma level of fibrinogen statistically differed from that in a group of the irradiated mice without a burn. It is suggested that endogenous infection and bacterial toxins are important at the pathogenesis of hyperfibrinogenemia and aggravation of CRTI outcomes by the 30-days survival criteria.

[Susceptibility of irradiated animals to extremely dangerous pathogens (literature review)]. / Chuvstvitel'nost' obluchennykh zhivotnykh k vozbuditeliam osobo opasnykh infektsii.

The review is dedicated to the susceptibility of irradiated animals anthrax, tularemia and other extremely dangerous infection diseases. Live vaccine strains application in irradiated animals and antibacterial drugs efficiency under conditions of combined effects of radiological and biological agents are reviewed. As a conclusion the list of unsolved research problems is proposed.

[Effects of modulators of cytokine levels on mice and rats survival under combined radiation/thermal injuries]. / Effekty moduliatorov urovnia tsitokinov na vyzhivaemost' myshei i krys pri kombinirovannykh radiatsionno-termicheskikh porazheniiakh.

The influence of LPS-induced increasing of proinflammatory cytokine production inhibitors (pentoxifylline--POF, glycine--G), Kupffer cells elimination (gadolinium chloride--GC) and monoclonal anti-IL-6 antibodies on 30-days survival, mean survival time and probability of mortality within animals under combined radiation/thermal injury were evaluated. Experiments were carrying out on mice (whole body gamma-irradiation at the dose of 7 Gy + 10% body surface full-thickness thermal burn) and rats (gamma-irradiation at the dose of 7.5 Gy + 15% body surface burn). It was established that POF, G and GC didn't modify survival. Mouse anti-IL-6 monoclonal antibodies administration 1 h prior and 1, 2, 3 days after combined injury increased 30-days animal survival up to 60% in each group and up to 90% while antibodies were injected in 6, 7, 8 days after combined injuries; 100% lethality was registered in untreated mice. Possible anti-inflammatory inactivity reasons of modulators of cytokine levels under combined injury conditions are discussed.

[Role of interleukin-6 (IL-6) in the pathogenesis of combined radiation/thermal injuries]. / Izuchenie roli interleikina-6 (IL-6) v patogeneze kombinirovannykh radiatsionno-termicheskikh porazhenii.

Combined injury such as whole body gamma-irradiation at the dose of 7 Gy+10% body surface full-thickness thermal burn were investigated in (CBA x C57BL6)F1 mice. Enhanced level of IL-6 in mice serum at 6-24 hs following combined injury was established. The potential inhibiting activity of pentoxifylline (POF) as an influence to IL-6 levels, and measure of several acute phase response signs has been evaluated. It was established, that single POF injection don't modify IL-6 production, don't change leukocytosis and early hyperfermentemia (as alaninaminotransferase levels indicated). But serum albumin content was increased after preliminary POF administration to mice with combined injury. On the other side, mouse anti-IL-6 monoclonal antibodies administration increased 30-days animal survival up to 60% while 100% lethality was registered in untreated mice. Possible anti-inflammatory inactivity reasons of POF under combined injury conditions are discussed in this article, and important role of IL-6 hyperproduction in combined injury outcomes burden is suggested.

[Efficacy of a preparation based on Lactobacillus acidophilus for protection from myelotoxic effects of ionizing radiation and antineoplastic cytostatics]. / Effektivnost' primeneniia preparata na osnove Lactobacillus acidophilus dlia zashchity ot mielotoksicheskogo deistviia ioniziruiushchei radiatsii i protivoopukholevykh tsitostatikov.

The ability of a Lactobacillus acidophilius (LA) based preparation to prevent from a myelotoxic damage was studied on (CBA.C57BL/6)F1 mice upon total gamma-irradiation or single intraperitoneal injection of cyclophosphan. The antitumor and antimetastatic activity of LA-based preparation was studied in experiments with C57BL/6 mice bearing Lewis lung carcinoma or melanoma B16. The preparation obtained from heat-killed Lactobacillus acidophilius species provides protection of hemopoietic stem cells, as evidenced by the amount of endogenous CFUs increased 3.4-6.7 times. The LA-based preparation favored accelerated overcoming the radiation- and cyclophosphan-induced leukopenia. At the same time, the drug did not affect the proliferative activity and apoptosis of tumor cells, their growth rate, and metastatic activity. Nor did it reduce the efficacy of the experimental tumor radiotherapy.

[Study of the possibility of hyperparathyroidism development in rats exposed to internal irradiation by iodine radioisotope]. / Issledovanie vozmozhnosti razvitiia giperparatireoza u krys, perenesshikh vnutrennee obluchenie ot radioizotopa ioda.

The possibility of hyperparathyroidism development secondary to earlier internal irradiation with radioactive iodine was studied experimentally in Wistar rats. This report describes the parathyroid morphology and biochemical findings for animals irradiated with 131I at the doses of 4.5, 40, or 80 Gy. The interval between the radiation exposure of two-month-old rats and their examination for thyroid and parathyroid pathology was 14 months. Neither hypercalcemia nor hypophosphatemia was found. Moreover, the level of calcium in serum slightly decreased following 40 and 80 Gy irradiation. The increased incidence of parathyroid fibrosis and hypofunctional structure transformation were revealed.

[Effect of microbial derived agents on the level of blood cytokines, hematological status and survival of mice following combined radiation injury]. / Vliianie sredstv mikrobnogo proiskhozhdeniia na uroven' tsitokinov v syvorotke krovi, gematologicheskii status i vyzhivaemost' myshei pri kombinirovannykh radiatsionnykh porazheniiakh.

Mice models of acute radiation and combined radiation injuries (whole body irradiation + thermal burn) were used for the experiments. Blood serum response of IL-1 beta, TNF-alpha, IL-6, IL-3, and GM-CSF was evaluated after single injection of bacterially derived products (BDPs). As it was established, BDPs revealed different ability for cytokine increasing activity: Imuvert (extract from Serratia marcescens) > synthetic trehalose dicorynomycolate > heat-killed Lactobacillus acidophilus. The capacity of BDPs to enhance survival of animals did not depend on its cytokine-inducing and hematopoietic activities.

[Increase in the level of metallothioneins in mouse liver after administration of cadmium chloride does not protect from combined radiation-thermal injury]. / Povyshenie soderzhaniia metalothioneinov v pecheni myshei posle vvedeniia khloristogo kadmiia ne zashchishchaet ot kombinirovannykh radiatsionno-termicheskikh porazhenii.

Effects of MT preinduction by cadmium chloride on the resistance to combined injury such as whole body gamma-irradiation at the dose of 7 Gy + thermal burn were investigated in (CBA x C57BL6)F1 mice. Normal level of MT markedly increased in mice liver but not in bone marrow cells if Cd was given subcutaneously (1 mg/kg) prior to combined injury. However, preinduction of MT did not reduce the lethal effects and bone marrow devastation caused by combined radiation injury. No differences in the leukopenia degree and in CFU-s number were observed between control and MT-induced mice. In summary, Cd-induced MT elevation in mice liver does not protect against the toxic and lethal effects caused by combined radiation injury.

Comparative analysis of proinflammatory cytokines in plasma of mice exposed to radiation or in combined radiation injury. / Sravnitel'nyi analiz urovnia provospalitel'nykh tsitokinov v syvorotkemyshei posle oblucheniia i kombinirovannykh radiatsionnykh porazhenii.

Male mice (CBA x C57BL/6)F1 were used for the experiments throughout this study. Blood serum levels of IL-1 beta, IL-6, TNF-alpha, IL-3, and GM-CSF were evaluated by means of enzyme-linked immunosorbent assay at 3, 6, 24, 48 and 72 hours after 7 Gy gamma-irradiation alone or combined injury (irradiation + thermal burn). Radiation as well as combined injury did not cause any important alterations of IL-1 beta, TNF-alpha, IL-3, and GM-CSF concentrations in the system circulation. Combined injury revealed more enhanced serum levels of IL-6 versus only irradiated mice. A possible significance of this phenomenon at the combined radiation and thermal burns' pathogenesis is discussed.

[Cytokine production by different population of macrophages following radiation or combined radiation injury]. / Produktsiia tsitokinov razlichnymi populiatsiiami makrofagov posle oblucheniia i kombinirovannykh radiatsionnykh porazhenii.

Male mice (CBA x C57BL6)F1 were used for the experiments throughout this study. The levels of spontaneous and LPS-stimulated cytokines production (IL-1 beta, IL-6 and TNF-alpha) by peritoneal, splenic, and bone marrow macrophages were evaluated by means of enzyme-linked immunosorbent assay at 3, 6, 24, 48 and 72 hours after irradiation alone or combined injury (irradiation + thermal burn). The results suggest that macrophages, harvested from the main mice hematopoietic organs (bone marrow, spleen), did not increase cytokines production within the first three days following the 7 Gy gamma-irradiation or combined injury. Peritoneal macrophages revealed a capacity to enhance IL-6 and IL-1 production versus normal healthy mice. There were no significant differences of cytokine-producing activity if macrophages were harvested from irradiated or combined injured mice.

[Antitoxic features of magnesium oxide under combined radiation and thermal injury]. / Antitoksichnye svoistva okisi magniia pri kombinirovannom radiatsionno-termicheskom porazhenii.

Male Wistar rats were exposed to 7.5 Gy total body gamma radiation followed to the additional full-thickness thermal bum. It was shown, that single administration of magnesium oxide in 1 hour after combined injury significantly corrected the early signs of endogenous intoxication. The level of bacterial endotoxemia decreased as well as serum concentration of toxic oligopeptides; general blood serum toxicity has been reduced too. Four-fold magnesium oxide's using as an enterosorbent in combination with antibiotics (doxycyclini, gentamicini or ciprofloxacin) has ensured 73-100% rats survival. All untreated animals dead within 30 days after combined injury.

[An interleukin-1 beta efficacy study in the treatment of combined radiation-thermal lesions]. / Issledovanie éffektivnosti interleikina-1 beta pri lechenii kombinirovannykh radiatsionno-termicheskikh porazhenii.

The experiments were carried out on F1 (CBA x C57B16) male-mice. It was shown that, in contrast to a therapeutic effect of IL-1 for the solely irradiated mice, a single subcutaneous injection of 100 micrograms/kg recombinant human IL-1 beta in 4 h after a combined radiation-thermal injury (CRTI) increased significantly the death rate of the animals within the first 2-4 days. Administration of 150 ng IL-1 per mouse in 4, 24, or 48 h after the CRTI decreased an average life-span of mice. A single injection of cytokine in 5 days after the CRTI increased the survival rate by 45%. Repeated injections IL-1 with a dose of 100 pg per mouse in 2, 4, and 6 days after the CRTI did not aid in the haematological indices and did not affect the survival rate of the animals.

[Changes in the hematopoietic system and in the concentrations of blood-regulatory cytokines after acute irradiation and a combined radiation-thermal lesion]. / Izmeneniia v krovetvornoi sisteme i v kontsentratsiiakh gemoreguliatornykh tsitokinov posle ostrogo oblucheniia i kombinirovannogo radiatsionno-termicheskogo porazheniia.

Acute radiation and combined radiation-thermal injuries (CRTIs) were modelled in the experiments on CBA x C57B16 mice. Changes in the concentrations of endogenic and lipopolysaccharide-induced TNF-alpha in the blood serum were measured in 3 to 24 h after gamma-irradiation at a dose of 7 Gy and a combined radiation-thermal injury. The status of mature and reserve pools of the bone marrow granulocytes was determined from the reaction of leukocytes mobilization to blood in response to the administration of interleukin-1 beta (IL-1 beta) in 48 h after Irradiation and CRTI. The contents of IL-3 and IL-6 in the blood serum, the level of cytokine secretion by the bone marrow cells were determined in vitro in the peak phases of acute radiation and combined injuries. No significant changes in the reaction of the bone marrow cells and in the level of pancytopenia were revealed after acute radiation and CRTIs, which could help in understanding an increase in the death rates after CRTIs. Also, quantitative changes in the TNF and IL-6 concentrations in the blood serum were estimated along with those in the level of secretion of IL-3 by the bone marrow cells of mice exposed to radiation and CRTIs.

Involvement of metallothioneins in regulation of macrophage activity after combined radiation and thermal injury.

The levels of reduced metallothioneins (MT) in peritoneal macrophages and liver of mice subjected to combined radiation and chemical injury displayed opposite changes: the macrophage level of MT decreased and the liver MT increased. Simultaneously, there was an increase in luminol- and lucigenin-dependent chemiluminescence of phagocytizing macrophages. Stimulation with CdCl2, a MT inducer, for three days before the injury increased the levels of MT in macrophages but decreased its liver levels. This effect was accompanied by a decrease in the intensity of the luminol-dependent but not lucigenin-dependent chemiluminescence. Administration of CdCl2 after the injury facilitated the induction of reduced MT in liver cells; however, its levels in macrophages remained low, and the intensity of their chemiluminescence did not decrease. The data suggest that MT is involved in oxidative metabolism and regulation of macrophage activity after combined radiation and thermal injury.

[Changes in the activity level of tumor necrosis factor in the blood serum after irradiation and a combined radiation-thermal lesion]. / Izmeneniia urovnia aktivnosti tumornekroticheskogo faktora v syvorotke krovi posle oblucheniia i kombinirovannogo radiatsionno-termicheskogo porazheniia.

To elucidate the role of the tumor-necrosis factor (TNF) in the pathogenesis of an additional aggravating effect of a thermal burn on the development and outcome of a radiation disease, the changes in the activity of cytokine in the blood serum of irradiated mice were studied. The mice were exposed to radiation at a dose of 7 Gy and subjected to a combined radiation-thermal injury (CRTI). The level of endogenous and LPS-induced TNF was determined in a cytotoxic test on a mice fibroblast L-929 culture. It was found that the activity of TNF in the blood circulation of mice subjected to irradiation and CRTI did not increase much. As a result of an intravenous injection of a provoking stimulus (LPS from E. coli), an increase in the TNF activity in the early period after irradiation was higher than with CRTI. There is no correlation between the increase in the death rate for mice with a combined injury and the changes in the LPS-induced TNF activity.

[Effects of previous small-dose irradiation on blood reaction and survival of mice after subsequent radiation and combined radiation-thermal injuries]. / Vliianie predvaritel'nogo oblucheniia myshei v maloi doze na reaktsiiu krovi i vyzhivaemost' pri posleduiushchikh luchevom i kombinirovannom radiatsionno-termicheskom porazheniiakh.

CBA x C57BL6 mice pre-exposed to 5 cGy gamma-irradiation then inflicted to LD70/30 acute radiation or combined injuries (radiation + thermal burn). In such protocol of the experiments preliminary "adaptive" dose radiation did not modify low 30-day survival rate and did not render an influence to the mean survival time. Leucopenia level and bone marrow devastation in 3 days after sublethal irradiation (4 Gy) or combined injury was similar in mice pre-exposed to low dose radiation (5 cGy) and in their unexposed controls. "Adaptive" dose radiation decreased leukocytes' number within the phase of hemopoiesis recovery (in 14 day after sublethal irradiation or combined injury).

[Biological preparation based on Lactobacillus acidophilus, a new agent in the early treatment of combined radiation-thermal injuries]. / Biopreparat na osnove Lactobacillus acidophilus--novoe sredstvo rannego lecheniia kombinirovannykh radiatsionno-termicheskikh porazhenii.

Male mice F1 (CBA x C57BL6) were used for experiments. Animals were exposed to 7 Gy gamma-radiation and additionally inflicted to full-thickness thermal burn 10% body surface. As it has been revealed, single subcutaneous injection of the created biopreparation based on inactivated lactobacillus microbic biomass increased mice survival with combined injury from 23% to 73%. Therapeutic efficacy of this remedy did not correlate with postradiation damages of the hemopoietic system. Injection of killed L. acidophilus mixture strikingly averted development of the intestine autoinfection. Possible mechanisms of the benefit therapeutic action of the new preparation are discussed.