Disorders of the Biochemical Composition of the Periodontium in Rats with Periodontitis and Chronic Pain Syndrome.

We analyzed the composition of the periodontal tissue in rats with experimental periodontitis and chronic pain syndrome. Chronic pain syndrome was induced by bilateral ligation of the sciatic nerve; experimental periodontitis was modeled by application of eight-shaped silk thread ligature to lower jaw incisors followed by its immersion into the periodontal groove and fixation with additional knots. A decrease in the concentration of oxyproline, glycosaminoglycans, and catalase activity and an increase in the content of malondialdehyde and acylhydroperoxides in the periodontal tissue were found in animals with experimental periodontitis throughout the experiment (7-21 days). In animals with chronic pain syndrome, modelling of experimental periodontitis led to more pronounced decrease in the concentration of oxyproline and glycosaminoglycans, increase in the content of acylhydroperoxides and malondialdehyde, as well as a decrease in catalase activity in the periodontal tissue.

Correction of Acute Parodontitis with Indolicidin Analogues.

We studied the influence of synthetic indolicidin analogues on the development of acute periodontitis. The corrective effect was found in indolicidin analogues Nos. 7 and 8; it manifested in a decrease in the edema of gingival epithelium and lamina propria, a decrease in the relative area of inflammatory infiltrates, and a significant increase in the relative area of normal connective tissue. These changes were revealed as soon as on day 14 and were most pronounced in 21 days after the removal of the ligature. Indolicidin analogues Nos. 7 and 8 demonstrated similar effectiveness on the model of acute periodontitis.

[Possible psychoemotional correction of psychophysical state in railway locomotive crew workers].

The article presents results of study concerning influence of relaxation sessions on emotional and psychophysical state of locomotive crew workers in special cabin for psychoemotional relief "Vivid silence" simulating rest in nature. Relaxation sessions appeared to cause better mood, lower blood pressure, increased reactions speed, reduced number of errors. Purposeful training of the specialists in self-regulation is extremely important for preparation to work activity and for prophylactic and social measures aimed to preserve and improve health in locomotive crew workers.

[Evaluating influence of Captopril therapy on occupational activity of engine operators with hypertension].

The article covers results of study concerning influence of Captopril (25 mg) therapy on occupational activity of locomotive crew workers in real night travels model on training complex "EP1M locomotive operator cabin". Findings are that single use of Captopril (25 mg) in modelled railway activity enabled to increase reliability of occupational activity, that manifested in lower number of errors in locomotive operators' actions at night, and in psychophysiologic regulation of various psychic acts.

[Mild cognitive disorders in railway locomotive crew workers (review of literature)].

Functional reliability of engine operator and engine operator's assistant is one of the most important factors in railway safety. Ability to railway locomotive operation is determined via suitability criteria of occupationally important qualities of operator and operator's assistant, and of nervous system functional state. Lower reliability manifested in worse functional state of engine operator or in lost occupationally important qualities can be connected with various diseases of which most prevalent are cardiovascular disorders. Transitory brain circulatory disorders can cause cognitive disturbances varying in severity. When mild cognitive disorders, precise diagnosis leads to effective prevention of the diseases development and preserved occupationally important qualities in engine operators. Neuropsychologic methods for mild cognitive disorders help not only to diagnose presence and intensity of cognitive defect, but to suggest a mechanism of its development, that eventually increases efficiency of correction.

Effects of Melatonin on Stress-Induced Changes in the Liver of Rats with Different Resistance to Stress.

Effects of melatonin on changes in the liver structures were studied in stress-resistant and stress-sensitive rats exposed to chronic stress. It was found that the number of degenerative cells increased and intralobular sinusoidal capillary enlarged in the liver of animals of both groups. These parameters were significantly higher in stress-sensitive rats. Melatonin (1 mg/kg) reduced the severity of degenerative changes and stimulated the development of reparative processes in the liver tissue. The effects of the hormone was more pronounced in rats sensitive to stress and was noted after melatonin administration in a dose of 0.2 mg/kg.

[Testing results of telemechanic system controlling train operators wakefulness].

Expert and instrumental assessment covered efficiency of telemechanic system controlling train operators wakefulness in simulation of real night travel, through special simulator complex "Locomotive operator cabin". The telemechanic system controlling train operators wakefulness, if exploited correctly, provides wakefulness of the train operators at the level sufficient for the effective work. That is supported by distribution of falling asleep cases in experiments with activated or deactivated telemechanic system controlling train operators wakefulness. The study proved efficiency of telemechanic system controlling train operators wakefulness.

[On psychologic profile of locomotive crew workers in Russian Railways JSC and its role in accidents prevention].

The article covers personality characters of locomotive crew workers of Russian Railways JSC, and specifying a block of methods for psychologic support of these workers' occupational activities. According to the results obtained, the authors presented a thorough description of characterologic, motivational personality traits characterizing a select of locomotive crew workers, and analyzed a relationship between the traits and levels of accidents in the workers' occupational activity.

[Influence of Melaxene on brain functional state].

The study covered influence of Melaxene on human brain functional state. Complex dynamic (12-hour) neurophysiologic study revealed that single dose of Melaxene (3 mg) influences brain functional state--reliably increases cross-correlation parameters of global spatial synchronization of cortex biopotentials in various ranges of EEG rhythms. Analysis of functional asymmetry of spatial synchronization of cortex biopotentials in various brain areas proved that Melaxene acitvates important cross-correlation links in spatial synchronization of cortex biopotentials in left and right brain hemispheres, with dominated activity of left hemisphere.

[The influence of melatonin on the content of lipid peroxidation metabolites and antioxidant enzyme activity in the liver of rats after immobilization].

The modeling of acute immobilization stress caused the increase of the content of lipid peroxidation metabolites and the decrease of the activity of superoxiddismutase and catalase in liver tissue within 4 days after stress. Melatonin in dose 0.2 mg/kg had a weak antioxidant effect and increased superoxiddismutase activity. The injection of melatonin in dose 1.0 mg/kg caused the significant decrease of lipoperoxidation metabolites content in liver tissue 39 hours after stress. On fourth and seventh days of the experiment there were no differences in malonic dyaldehyde content between these animals and naive ones. The concentration of acylhydroperoxides was significantly less than in control and naive groups at these days. The activity of superoxiddismutase and catalase was significantly more than in control rats at the fourth day after stress.

[The influence of melatonin on lipid peroxidation and antioxidant enzymes activity during multiply repetitive stress actions].

It was established that the modeling of the repeated immobilization stress is accompanied by the increase of the content of lipid peroxidation metabolites and the decrease of antioxidant enzymes activity (superoxiddismutase and catalase) in both blood plasma and liver tissue. Intraperitoneal melatonin injections in the doses 0.2 or 1 mg/kg during 7 days cause the decrease of the content of lipid peroxidation metabolites in both blood plasma and liver tissue in animals after prolonged stress, as well as leads to the increase superoxiddismutase activity in both blood plasma and liver tissue in comparison with the control group. In liver tissue catalase activity increased after the melatonin application at both doses in comparison with control animals, but in plasma the same change was observed only after 1 mg/kg melatonin inject. The results of investigation confir- med the literature data about the antioxidant effects of melatonin and opened the perspectives of its using for the prevention of stress-induced organ injury.

Bone marrow stem cells repopulate thyroid in X-ray regeneration in mice.

The aim of this study was to clarify the regeneration mechanisms of thyroid in post-irradiated C57Bl/6 mice chimeric with transgenic green fluorescent protein (GFP) positive C57Bl/6 mice after 5 and 7.5Gy X-ray exposures with the aid of morphological and immunocytochemical research of GFP-positive cell distribution. Cryostat slides of larynxes with thyroid glands were fixed by mixture of cold methanol and ethanol, cell nuclei were stained with propidium iodide. After immunocytochemical staining the slides of larynx with thyroid gland were investigated by means of confocal LSM 5 PASCAL microscope. True GFP nature of green signals in tissue slides was confirmed via additional treatment by anti-GFP antibody and Texas Red labeled second antibody. Separate GFP-positive cells were observed in the walls of follicles and between follicles of chimeric mice 9-10 months after X-ray exposure. GFP signal was viewed as cytoplasmic droplets and within the colloid of follicles. The share of GFP-positive follicles reached 6.1±1.8%. There was also co-localization of GFP signals and positive staining for thyroglobulin by monoclonal antibody. As many as 20.8±1.8% among all propidium iodide positive blood cells and 52.3±8.3% among propidium iodide positive bone marrow cells were at the same time GFP-positive. In conclusion, the results show that the bone marrow stem cells participate in the thyroid gland regeneration after 5Gy X-ray exposure.

Forskolin decreases phosphorylation of histone H2AX in human cells induced by ionizing radiation.

Forskolin is a natural compound found in the coleus herb that activates the enzyme adenylate cyclase and increases the concentration of intracellular cyclic AMP (cAMP). This chemical is widely used as a stimulating food additive. It is unknown whether forskolin can effect cellular responses to ionizing radiation, such as induction of phosphorylation of histone H2AX (gamma-H2AX) in megabase chromatin domains near DNA double-strand breaks (DSBs). Here we report that treatment with forskolin decreases H2AX phosphorylation after irradiation detected by immunoblotting or by analysis of the overall gamma-H2AX-associated fluorescence in the nuclei. However, this chemical does not affect the number of gamma-H2AX foci, the frequency of radiation-induced chromosome aberrations, or cell survival after X irradiation, which is consistent with the view that it does not change the induction of repair of DSBs. We suggest that the overall decrease of H2AX phosphorylation after treatment with forskolin in irradiated cells reflects a lesser extent of apparent H2AX modification at individual DSBs that may be caused by inhibition of the initial spread of gamma-H2AX and/or by stimulation of elimination of gamma-H2AX from chromatin after DSB rejoining.

[Participation of bone-marrow stem cells in the differentiation of mdx mice striated muscle].

Two sets of experiments were carried out. The first one involved chimeric mice, obtained by intravenously injections of bone marrow derived cells taken from transgenic C57BL/6 mice, expressing GFP, to 5 Gy X-ray irradiated mdx or C57BL/6 mice. In 2 months M. quadriceps femoris of chimeric mice were destroyed by surgical clamp. Following the next 4-5 weeks, the same muscles were studied for the presence of GFP-positive striated muscle fibres. In the case of chimeric C57BL/6 mice GFP-positive striated muscle fibres were observed in 0.3 +/- 0.5 and in 0.2 +/- 0.3 % of destroyed muscle, and in lateral (control) muscle, consequently. In the case of chimeric mdx mice, positive results were observed in 1.7 +/- 0.4 and in 0.5 +/- 0.3 % of destroyed and control muscles, respectively. In the second set of experiments, the GFP-positive bone marrow cells were used for multiple intramuscular injections to M. quadriceps femoris of C57BL/6 or mdx mice in a dose of 2 x 10(5)-5 x 10(5) cells per mouse. Before injection, GFP-positive bone marrow cells were fractionated in a 63 % Percoll solution and then were exhausted from differentiated cells by magnetic manner using CD4, CD8, CD38, CD45R, CD119, Ly-6G, and F4/80 antibodies. After 2-3 weeks, as many as 0.15 +/- 0.40 and 0.1 +/- 0.2 % of GFP-positive muscle fibres were found in injected and control muscles of C57BL/6 mice, respectively. In the case of mdx mice, the frequency of GFP-positive striated muscle fibres was 2.0 +/- 0.8 and 1.2 +/- 0.6 % for injected and control muscles, respectively. A conclusion is made that bone marrow stem cells can take part in differentiation of mdx mouse muscles after their delivery by needle injections.

BM-derived cells restore expression of peroxiredoxin V in the airways following acute naphthalene injury in mice.

BACKGROUND: Naphthalene-induced respiratory tract toxicity in mice is characterized by specific and rapid loss of the Clara cell population, which is restored only after several days. The sources of restoration of this cell population remain unclear. We investigated whether BM-derived cells participated in the process of epithelial restoration following naphthalene toxicity compared with bacterial infection. We further investigated the role of BM-derived cells in restoration of expression of peroxiredoxin V (PRXV), one of the major proteins of antioxidant defense, specifically expressed in the bronchial epithelium. METHODS: We transplanted GFP-tagged BM cells into 5 Gy-irradiated C57BL/6 recipients. Following 1 month of recovery, experimental animals were subjected to 250 mg/kg naphthalene i.p. An additional group of animals received intratracheal instillation of Escherichia coli to induce acute bacterial inflammation. Animals were killed at 1-12 days after naphthalene and analyzed immunohistochemically. RESULTS: Recipients' cells of bronchial epithelium demonstrated significantly reduced levels of PRXV expression following naphthalene. In animals with acute bacterial inflammation, PRXV levels were not reduced in epithelium and participation of BM-derived cells in epithelial restoration was minimal. Following naphthalene, GFP(+) cells were present in large numbers in lung parenchyma and epithelium of conducting airways starting at 1 day following injury. GFP(+) progeny of BM cells was the major source of PRXV in the epithelium. DISCUSSION: These data suggest that BM-derived cells may provide a source of antioxidant protection of airways by expression of PRXV in a model of acute epithelial respiratory tract toxicity.

[Participation of transfused bone marrow cells in reparative osteohistogenesis].

The participation of skeletal tissue cell precursors in the repairing regeneration of bone tissue was studied. Bone marrow was taken from donor animals--mice of C57Bl/6-TgN(ACTbGFP) 1 Osb line (The Jackson Laboratory Bar Harbor ME USA line). Nucleated cell fraction was isolated by centrifugation on a density percoll gradient. Recipient mice C57Bl/6 line were irradiated by 7.0-7.5 Gr dose. Intravenous infusion of donor cells and osteoclasts of tibia was done after irradiation of recipient mice. Histological preparations of bone regenerate tissues were studied on 15, 30, and 60 days by confocal microscopy. Donor cells were found as skeletal tissue precursors into periost, endost, bone marrow, and as differentiated cells of newborn tissue of regenerate--osteoblasts, osteocytes, chondrocytes. The data obtained indicate that part of donor bone marrow cells are able to progressive differentiation under recipient bone fractures.

Effects of the ventilation pattern and pulmonary blood flow on lung heat transfer.

To investigate the relative role of pulmonary perfusion compared to ventilation on lung heat exchange, we determined the effects of blood flow, tidal volume and frequency of ventilation on the rate of lung heat transfer. In anesthetized dogs and isolated, perfused lungs, we investigated the dependence of the overall lung heat transfer coefficient (HTC) and lung thermal capacitance upon ventilation and pulmonary blood flow. The relationship between the HTC and pulmonary blood flow was strongly dependent on ventilation parameters. A distributed model of non-steady-state heat exchange adequately described these observations and demonstrated that changes in pulmonary blood flow may be considered as changes in the effective conductivity of the bronchial walls as 0.4 (0.1) J s(-1)m(-1) K(-1) per (l/min(-1)) of pulmonary blood flow. Our model describes the complex relationship between HTC, ventilation pattern, and effective thermal conductivity of the bronchial walls, all of which present limitations for the use of lung heat transfer to determine pulmonary blood flow.

Estimate of the subepithelial hydrostatic pressure that drives inflammatory transudate into the airway lumen.

Inflammatory diseases of the upper respiratory tract are characterized by flow of plasma filtrate across the epithelium into the airway lumen ("transudation"). Elsewhere, we have proposed that extravasation from microvessels causes edema, and this is associated with elevated subepithelial hydrostatic pressure that drives transudation. To test this hypothesis, we have attempted to block transudation by elevating luminal hydrostatic pressure. We measured the appearance of plasma markers into the lumen of an isolated perfused segment of rat trachea in vivo and found that stimulation of one vagal nerve caused a rapid (half-time approximately 5 min) and nonselective increase in the flow of markers from blood to airway lumen. Leukocyte migration also caused transudation that developed much more slowly (half-time = 2-3 h). In both cases, transudation was blocked by application of luminal hydrostatic pressures. The critical luminal pressure needed to block vagally induced transudation was approximately 4.5 cmH2O, and, to block epithelial transudation induced by leukocyte traffic, it was 3 cmH2O, and we conclude that these are the subepithelial pressures that drive inflammatory transudation into the airway lumen.