Peroxiredoxin 6 is a natural radioprotector.

After injection of 20 mg/kg peroxiredoxin 6 to male Kv:SHK mice 15 min before X-ray irradiation in the range of lethal doses (7-10 Gy), the mice remained alive for 30 days, whereas the mortality of the control animals was 100%. In the irradiated animals, peroxiredoxin 6 decreased the severity of radiation-induced leucopenia, granulocytopenia, and thrombocytopenia, increased the number of blood corpuscles, and prevented the mass death of epithelial cells and the destruction of the small intestine. Thus, peroxiredoxin 6 can be regarded as a prophylactic radioprotective agent.

Pro-oxidative, genotoxic and cytotoxic properties of uranyl ions.

It is demonstrated that hydroxyl radicals and hydrogen peroxide are formed under the action of uranyl ions in aqueous solutions containing no reducing agents. In the presence of uranyl ions, formation of 8-oxoguanine in DNA and long-lived protein radicals are observed in vitro. It is shown that the pro-oxidant properties of uranyl at micromolar concentrations mostly result from the physico-chemical nature of the compound rather than its radioactive decay. Uranyl ions lead to damage in DNA and proteins causing death of HEp-2 cells by necrotic pathway. It is revealed that the uranyl ions enhance radiation-induced oxidative stress and significantly increase a death rate of mice exposed to sublethal doses of X-rays.

[Impact of biologically important anions on reactive oxygen species formation in water under the effect of non-ionizing physical agents].

The influence of biologically relevant anions (succinate, acetate, citrate, chloride, bicarbonate, hydroorthophosphate, dihydroorthophosphate, nitrite, nitrate) on the formation of hydrogen peroxide and hydroxyl radicals in water was studied under the effect of non-ionizing radiation: heat, laser light with a wavelength of 632.8 nm, corresponding to the maximum absorption of molecular oxygen, and electromagnetic radiation of extremely high frequencies. It has been established that various anions may both inhibit the formation of reactive oxygen species and increase it. Bicarbonate and sulfate anions included in the biological fluids' and medicinal mineral waters have significant, but opposite effects on reactive oxygen species production. Different molecular mechanisms of reactive oxygen species formation are considered under the action of the investigated physical factors involving these anions, which may influence the biological processes by signal-regulatory manner and provide a healing effect in physical therapy.

[Generation of reactive oxygen species in water under exposure of visible or infrared irradiation at absorption band of molecular oxygen].

It is found that in bidistilled water saturated with oxygen hydrogen peroxide and hydroxyl radicals are formed under the influence of visible and infrared radiation in the absorption bands of molecular oxygen. Formation of reactive oxygen species (ROS) occurs under the influence of both solar and artificial light sourses, including the coherent laser irradiation. The oxygen effect, i.e. the impact of dissolved oxygen concentration on production of hydrogen peroxide induced by light, is detected. It is shown that the visible and infrared radiation in the absorption bands of molecular oxygen leads to the formation of 8-oxoguanine in DNA in vitro. Physicochemical mechanisms of ROS formation in water when exposed to visible and infrared light are studied, and the involvement of singlet oxygen and superoxide anion radicals in this process is shown.

The human immunoglobulin loci introduced into mice: V (D) and J gene segment usage similar to that of adult humans.

Variable gene segments of the human immunoglobulin loci are represented in the human peripheral repertoire at different frequencies. XenoMouse strains contain approximately 2 megabases of the human immunoglobulin heavy and kappa light chain loci that functionally recapitulate the human humoral immune system. Analysis of human antibody transcripts from XenoMouse spleens and lymph nodes revealed that V, D and J gene segment utilization from these unimmunized animals were nearly identical to the gene segment utilization reported for humans with extensive antigenic histories.

[The effect of tropoxin on the neurogenic and vasogenic inflammation of the dura mater vessels]. / Vliianie tropoksina na neirogennoe i vazogennoe vospalenie sosudov tverdoi mozgovoi obolochki.

Subchronic administration of tropoxin (in doses of 7.5 and 10 mg/kg) caused dose-dependent blocking of 131I-albumin plasma transudation from the dura mater vessels, induced by electrical stimulation of the trigeminal ganglion and intravenous infusion of the agonist of 5-HT2B/2C receptors metachlorophenylpiperazine. The antimigraine agent metisergid produced a similar effect. A single injection of metisergid and tropoxin did not block albumin transudation. A 3 mg/kg dose of mianserin prevented the blocking effect of tropoxin and metisergid on plasma exudation into the dura mater. It is suggested that the mechanism of the tropoxin antimigraine effect is realized through the presynaptic 5-HT1 receptors of afferent endings of the trigeminal nerve and the postsynaptic 5-HT2B/2C receptors of the dura mater vessels.

[The effect of klofelin on the activity of the sensory neurons of the trigeminal complex induced by stimulation of the superior sagittal sinus]. / Vliianie klofelina na vyzvannuiu stimuliatsiei verkhnego sagittal'nogo sinusa aktivnost' sensornykh neironov troinichnogo kompleksa.

In doses of 0.25 and 0.5 mg/kg clophelin inhibited the responses of the trigeminal complex sensory neurons to electrical stimulation of the superior sagittal sinus in conscious immobilized rats. Naloxon (0.1 mg/kg) and yohimbine (1 mg/kg) weakened whereas prazosin (1 mg/kg) did not affect the inhibiting effect of clophelin.

[The effect of clofelin on the transudation of plasma proteins into the dura mater induced by stimulation of the trigeminal ganglion]. / Vliianie klofelina na propotevanie belkov plazmy v tverduiu mozgovuiu obolochku, vyzvannoe stimuliatsiei troinichnogo gangliia.

Intravenous administration of clofelin blocks transudation of 131I-albumin into the dura mater of rats in electrical stimulation of the trigeminal ganglion. Preliminary injection of the alpha-adrenoblocker yohimbine and the antagonist of serotonin receptors 5-NT1 mianserin completely removes the blocking effect of clofelin. Naloxon and the alpha 1-adrenoblocker prazosin had no effect on the degree of expression of albumin transudation and the clophelin effect. The role of the adrenergic system, the presynaptic alpha 2-adrenoceptors in particular, in functioning of the trigeminovascular system and the development of neurogenic inflammation in the dura mater is discussed.

[Study of mechanisms of action of amitriptyline and acupuncture using nociceptive flexor reflex in patients with chronic forms of headache]. / Izuchenie mekhanizmov deistviia amitriptilina i akupunktury s pomoshch'iu notsitseptivnogo sgibatel'nogo refleksa u patsientov s khronicheskimi formami golovnykh bolei.

The nociceptive flexor reflex (NFR, R3) was tried for quantitative assessment of pain in patients with various forms of primary and secondary headaches. Amitriptyline and acupuncture elevated the threshold of R3-reflex emergence, though the threshold of subjective pain sensitivity increased only in response to amitriptyline. NFR is adequate for assessing anesthesia efficacy and investigating the mechanisms of action of analgesics in patients with headache.

Infant leukemia in Belarus after the Chernobyl accident.

Petridou et al. [1] have reported an increase in infant leukemia in Greek children born between 1/7/86 and 31/12/87 and have linked this increase to in utero radiation exposure due to the Chernobyl accident. Subsequently, Michaelis et al. [2] have reported a similar trend for Germany but found that it was not correlated to the levels of contamination. For Belarus, which was much more severely affected, a similar but much weaker trend is found.

[Unstable chromosome aberrations in lymphocytes of liquidators of the Chernobyl accident consequences]. / Nestabil'nye khromosomnye aberratsii v limfotsitakh uchastnikov likvidatsii posledstvii avarii na Chernobyl'skoi AES.

AIM: Analysis of peripheral blood lymphocytes for detecting unstable chromosome aberrations in liquidators of the Chernobyl disaster consequences and in residents of territories contaminated after the accident. MATERIALS AND METHODS: Peripheral blood lymphocytes were tested for unstable chromosome aberrations in 216 subjects who worked for different periods after the Chernobyl accident in 1986-1987 in the 30-km zone and at adjacent territories. The results were correlated to the duration of stay in the zone, terms of examination after the work, exposure dose fixed in the files, deviations in the health status and blood values, and with similar data on 21 residents of the stringent control regions of the Gomel district and 265 patients with different hematological diseases and donor blood samples exposed in vitro. RESULTS: Chromosome aberrations detected in the examined group are represented by dicentrics, paired and nonpaired fragments, acentric rings, and gaps. CONCLUSION: Although not everything is yet clear, we consider that detection of unstable chromosome aberrations of the dicentric type in lymphocytes of subjects who participated in liquidation of the accident consequences in remote periods after exposure persuasively proves that a radiation exposure, no matter what its dose was, took place, and hence, there are good grounds for including the subjects with aberrations in the high risk group. On the other hand, the absence of such aberrations does not rule out the detrimental effect of radiation on the organism.

[The effect of guanfacine on the background and nociceptive stimulation-induced activity of spinal cord neurons in rats]. / Vliianie guanfatsina na fonovuiu i vyzvannuiu notsitseptivnym razdrazheniem aktivnost nelronov spinnogo mozga u krys.

Guanfacine in analgesic doses of 2.0 and 4.0 mg/kg inhibits the background activity of the spinal cord posterior horn neurons and their responses to nociceptive stimulation of the receptive field in conscious rats. Naloxone (0.1 mg/kg) does not change, whereas prazosin and yohimbine (both on doses of 0.1 mg/kg) remove and partly relieve the depressant effect of guanfacine.

Post Chernobyl Hemoblastoses in the Republic of Belarus (brief communication).

Data on the incidence of acute leukemia (AL) in children in the Byelorus Republic is analysed and comparisons made between the incidence of AL prior and subsequent to the Chernobyl accident in 1986. The Byelorus Republic was directly and heavily contaminated at that time and careful records of the incidence of cases of AL and other malignancies have since been kept. Byelorus is divided into large administrative regions-oblasts-which are subdivided into raions. Both the levels of radiation and estimates of chemical pollution in these areas are available. Childhood AL incidence appears to be unrelated to radiation dosage in that no increases were seen in the more radiation contaminated areas. However there appeared to be a more likely relationship with chemical pollution. Adult AL and other myeloproliferative and lymphoproliferative disorders have appeared to increase since 1986 but again the authors attribute this more to rising levels of chemical pollution possibly associated with radiation as a coleukemogen.

Enzyme-linked immunosorbent assay for human MRP-8/MRP-14 proteins and their quantitation in plasma of hematological patients.

We developed a quantitative enzyme immunoassay for human MRP-8/MRP-14, neutrophil cytosolic proteins with calcium-binding and bacteriastatic properties. MRP-8/MRP-14 concentrations were measured in the plasma of 23 healthy volunteers and in 75 patients with hematological disorders. These proteins were detected in plasma of healthy blood donors with mean +/- standard deviation 167 +/- 114 ng/ml. MRP-8/MRP-14 plasma levels ranged from 435 to 13280 ng/ml in patients with chronic myeloid leukemia (CML), from 50 to 7570 ng/ml in chronic lymphoid leukemia (CLL), from 450 to 2790 ng/ml in polycythemia vera (PV), and were significantly higher than in healthy blood donors (P < 0.01 for CML and P < 0.05 for others). In CML patients MRP-8/MRP-14 levels strongly correlated with total blood WBC count (r = 0.82) and with neutrophilic granulocyte (NG) count (r = 0.80). Correlation of these values in PV amounted to r = 0.70 and r = 0.46, respectively. In CLL patients MRP-8/MRP-14 levels strongly correlated with total WBC count (r = 0.92), but not with the NG count. We suggest that MRP-8/MRP-14 quantitation may serve as a marker of neutrophil pool turnover in some hematological disorders.

[First results of bone marrow transplantation in acute and chronic leukemia at the Byelarus Center for Bone Marrow Transplantation]. / Pervye rezul'taty transplantatsii kostnogo mozga ostrykh i khronicheskikh leikozakh v Belorusskom tsentre transplantatsii kostnogo mozga.

The first 10 bone marrow transplantations (BMT), 6 of the allogenic (allo-BMT) and 4 autologous (auto-BMT) were performed from February to June 1994 in Byelarus Center for Bone Marrow Transplantation. Two of the patients were experiencing the first complete remission of acute lymphoblastic leukemia (ALL), one of them - the first ALL recurrence, three patients with acute myeloblastic leukemia had the first complete remission, four patients had a chronic phase of chronic myeloid leukemia. In auto-BMT bone marrow (BM) was stored in liquid hydrogen after programmed freezer. An average yield of nucleated cells (NC) after taking and separation of allo-BM made up 3.0 x 10(8) cell/kg and 2.7 x 10(8) cell/kg in auto-BMT. After thawing of BM NC yield reached 1.5 x 10(8) cell/kg (0.8-2.3) x 10(8) cell/kg. CFU concentrations persisted at 24.7 x 10(4) (5.0-40.4) x 10(4) cell/kg body weight. The mean duration of leukocyte, neutrophil and platelet rise to the levels of over 1.0 x 10(9)/l, 0.5 x 10(9)/l, 20 x 10(9) cell/l, respectively, and the last time red cells were transfused were 23 (19-33), 23 (19-31), 22 (9-51), 4.5 (0-19), respectively. One ALL (first complete remission) patient died on day 52 after allo BMT of severe hepatic venous-occlusive disease. The other ALL patient (the first relapse) developed another relapse on day 112 after BMT. The rest 8 patients are in satisfactory condition.

Frequencies of unstable chromosome aberrations in peripheral blood lymphocytes of Chernobyl emergency accident workers.

On the basis of the investigation of unstable chromosome aberrations in peripheral blood lymphocytes of Chernobyl accident emergency workers, of residents of the contaminated areas, of patients with blood diseases and of donor's blood irradiated in vitro it is stated that presence of unstable chromosome aberrations such as dicentrics in lymphocytes of emergency workers and residents indicates that they have been overexposed. However, in the absence of the described aberrations in individuals involved in emergency work or in residents years after accident it is impossible to reject the overexposure.

[The effect of hemodialysis on lipid peroxidation]. / Vliianie gemodializa na perekisnoe okislenie lipidov.

With regard to the variance in the levels of lipid peroxidation products (malonic dialdehyde and diene conjugates) the authors studied the impact of hemodialysis on lipid peroxidation. Transitory activation of lipid peroxidation with a subsequent decrease in the levels of lipid peroxidation products that were lower than initial ones were noted at the initial stages of hemodialysis performed with the use of a DEP-02-02 dialyzer (with a cuprophane membrane). The comparison of the input and output levels of lipid peroxidation products failed to demonstrate any generation of lipid peroxidation products inside the dialyzer. The systemic character of the activation effect in the onset of dialysis was established. It was proved that the effect did not depend on the material used for the membrane as there was no rise in the levels of lipid peroxidation products but a decrease in their concentration when the capillary dialyzers D1 and B2-100 were used. The study of the washings from the cuprophane membrane from the dialyzer DEP-02-02 demonstrated high levels of endotoxin which were several times higher than in those from the same membrane from the dialyzer D2. Endotoxin release into the circulation probably determined the transitory effect of the activation in the onset of the procedure performed with the dialyzer DEP-02-02. The authors discussed the possible origin of high initial levels of lipid peroxidation products observed in patients with terminal chronic renal failure who had undergone hemodialysis.

[Determination of soluble complexes of fibrin monomers in plasma taking into consideration the fibrinogen level]. / Opredelenie rastvorimykh kompleksov monomerov fibrina v plazme s uchetom urovnia fibrinogena.

Quantitative modifications of beta-naphthol, ethanol, and protamine sulfate tests are described, which are based on spectrophotometry of the formed precipitate. The findings have demonstrated a correlation between these tests' results and the plasma fibrinogen concentration. It is recommended that the paracoagulation test parameters be estimated with consideration for fibrinogen level. The results of measurements of the plasma fibrin monomer soluble complexes in 13 donors and in 72 patients with blood diseases and hemostasis are presented. The results permit a conclusion that these tests used alone or in various combinations are sufficiently sensitive, specific, and informative for the examinations of patients with disseminated intravascular coagulation; combined use of three paracoagulation tests has been found to be optimal.

Cardiac metabolism and performance during L-glutamic acid infusion in postoperative cardiac failure.

Intravenous infusion of L-glutamic acid results in the augmentation of the cardiac output and an improvement of the circulation in patients with postoperative cardiac failure. This effect is not accompanied by increased myocardial oxygen demand. Arterial plasma glutamate level rises 10-fold and arterial-coronary sinus plasma glutamate difference increases fivefold during intravenous L-glutamic acid infusion. This leads to cessation of ammonia release from the myocardium, probably due to augmentation of glutamine synthesis and to an increase in alanine formation coupled with a change from lactate release to lactate uptake by the myocardium. The data obtained suggest that the beneficial effect of L-glutamic acid on depressed cardiac function in postoperative patients is related to changes in myocardial metabolism. Glutamic acid may be useful in treatment of circulatory and metabolic disturbances in cardiac failure.