[Complex cytogenetic characteristic of people suffered from Chernobyl accident]

A cytogenetic study was performed on Chernobyl cleanup workers, on their children, on persons evacuated from contaminated aeria (adult and children), on so named "veterans of particular risk" irradiated due to the accidents on the nuclear plant, testing of nuclear weapons etc. and on control donors. The yield of stable (FISH analysis) and of unstable chromosome aberrations, micronuclei in both lymphocytes and erythrocytes, HPRT mutations was found to be increased in exposed groups as compared to control ones. In children of liquidators and in evacuated children we observed genomic instability and increased in vitro chromosomal radiosensitivity. Acceleration of age accumulation of translocations characterized the exposed population in comparison with control group. People with the highest level of routine chromosome aberrations had cardiovascular and digestive diseases more often likely than those with the lowest level. In frame of International Project ECP-6--"Biological dosimetry" the dose-responses for dicentrics and translocations were constructed in dose range 0-100 cGy of gamma-irradiation on the base of data of 8 laboratories. On cancer patients undergone whole-body gamma-irradiation (every day at the dose 11.5 cGy to a total of dose 57.5 cGy) we constructed the dose-responses for the dicentrics and translocations and compared them with the dose-responses for these aberrations after the in vitro irradiation of lymphocytes of the same patients. For the dicentrics the effectiveness of the in vivo irradiation was less than of the in vitro one. No differences were found for translocations.

Monomeric and Multimeric Blockers of Selectins: Comparison of in vitro and in vivo Activity

The potency of the oligosaccharides SiaLe(x), SiaLe(a), HSO(3)Le(x), and HSO(3)Le(a), their conjugates with polyacrylamide (PAA, 40 kD), and other monomeric and polymeric selectin inhibitors has been compared with that of the polysaccharide fucoidan. The following assay systems were used: 1) a 96-well assay based either on the use of recombinant E-, P-, and L-selectins or an analogous assay with natural P-selectin isolated from human platelets; 2) a platelet-based P-selectin cell assay; and 3) a rat model of peritoneal inflammation. IC(50) values for the neoglycoconjugate SiaLe(a)-PAA were 6, 40, and 85 microM for recombinant E-, P-, and L-selectins, respectively; all monomeric inhibitors were about two orders of magnitude weaker. PAA-conjugates, containing as a ligand tyrosine-O-sulfate (sTyr) in addition to one of the sialylated oligosaccharides, were the most potent synthetic blockers in vitro. Compared with fucoidan, the most potent known P- and L-selectin blocker, the bi-ligand glycoconjugate HSO(3)Le(a)-PAA-sTyr displayed similar inhibitory activity in vitro towards L-selectin and about ten times lower activity towards P-selectin. All of the tested synthetic polymers displayed a similar ability to inhibit neutrophil extravasation in the peritonitis model (in vivo) at 10 mg/kg. The data provide evidence that monomeric SiaLe(x) is considerably more effective as a selectin blocker in vivo than in vitro, whereas the opposite is true for fucoidan and the bi-ligand neoglycoconjugate HSO(3)Le(a)-PAA-sTyr.

[Age dymamics of stable chromosome aberration frequency in humans with natural and pathological senescence]

The age dynamics of stable chromosome aberration (SCA) frequency was analysed by fluorescent in situ hybridization (FISH) in human blood lymphocytes derived from donors, irradiated by low doses of ionizing radiation (Chernobyl clean-up workers, nuclear weapon testers, etc.) and patients with hereditary premature aging--Werner's syndrome and Hutchinson-Gilford's syndrome. It was found that the level of SCA was age-dependent and increased in irradiated persons. So, the SCA level may be really an index of a so-called "radiation senescence", and may show a real biological age of irradiated persons. The patients with Werner's syndrome demonstrate increased SCA level in blood lymphocytes, corresponding to the premature aging of the organisms. But in the case of another form of premature aging--Hutchinson--Gilford's syndrome-- no rise of SCA level was found. Some possible reasons of such results are discussed.

[Activity of blood platelets and functional state of endothelium in patients with unstable angina with favorable and unfavorable outcome (prospective study)]

Functional activity of platelets (aggregation and plasma levels of soluble P-selectin) and functional state of endothelium (antiaggregatory activity of vessel wall - AAVW, cuff occasion test, and plasma content of von Willebrand factor) were assessed in patients with unstable (n=41) and stable (n=19) angina and healthy donors (n=20). According to results of follow up for 1 year patients with unstable angina (UA) were divided into 2 groups - with (n=21) and without (n=20) events (coronary death, nonfatal myocardial infarction). In patients with UA and events parameters of spontaneous and ADP-induced platelet aggregation, contents of P-selectin and von Willebrand factor were higher while AAVW lower than in UA patients without events, patients with stable angina and healthy subjects. Correlations between AAVW and platelet aggregation, between AAVW and level of von Willebrand factor were negative in patients with UA, and positive in patients with stable angina and healthy subjects. These results of correlation analysis were interpreted as a reflection of impairment of antithrombotic endothelial function in patients with UA.

[Pharmacodynamics, safety, and clinical effects of a novel glycoprotein IIb/IIIa antagonist framon during high risk coronary angioplasty]

Preparation framon [F(ab')2 fragments of the anti-glycoprotein (GP) IIb/IIIa monoclonal antibody (FRaMon)] blocks fibrinogen binding to GP IIb/IIIa and platelet aggregation. Dynamics of platelet aggregation inhibition, safety, and clinical effects of framon were studied in high-risk coronary angioplasty. Twenty seven patients underwent angioplasty with framon, 29 - with abciximab and 28 - with no GP IIb/IIIa antagonists. Framon at 0.2 mg/kg (n=16) and 0.25 mg/kg (n=11) bolus administration inhibited platelet aggregation induced by 20 mcM ADP by more than 90%, 80%, 60% and 30% in comparison with the predrug level 1, 12, 24 and 72 h after injection, respectively. Almost the same dynamics of aggregation inhibition was observed upon abciximab administration at 0.25 mg/kg bolus + 0.125 mcg/kg/min infusion for 12 h. No signs of individual intolerance and side effects including allergic reactions and bleedings were detected in patients treated with framon. Slight decrease of platelet count (15-20%) was observed on the first day after framon administration. Antibodies against framon were detected in 1 out of 22 tested patients. Free (nonbound to platelets) framon was completely removed from the circulation 12 h after injection. The number of endpoints (death, myocardial infarction and indications for repeat revascularization) within 1 year after angioplasty was approximately the same in the groups with framon and abciximab - 7 of 25 (28%) and 7 of 28 (25%), respectively, and more than 1.5 fold higher in the group without GP IIb/IIIa blockers - 12 of 27 (44,4%).

[KRT-"Electron" remote control X-ray equipment complex]

The paper contains data on the remote control X-ray diagnostic sets designed, in Russia, by the "Electron" Research and Instrument-Making Co. Ltd.

[Chlamydia infections in children with acquired cicatricial laryngeal and tracheal stenosis]

The examination for Chlamydial infection was carried out in 49 children aged from 1 year 10 months to 15 years (mean age 9 years 6 months +/- 3 years 8 months) with laryngotracheal cicatricial stenosis (CS) provoked by long nasotracheal intubation. Antibodies to C. pneumoniae in diagnostically significant titers were detected in 13 of 49 children (26.5%), to C. trachomatis--in 1 patient who had both infections. All the infected patients except the latter carried tracheal canules or were decanulated. Age of the patients with Chlamydial infection at the time of examination and development of CS was significantly older than of non-infected children. No significant difference was found between these patients by duration of the intubation and of the disease. Consideration of the fact that 12 of 13 children with C. pneumoniae infection carried tracheocanules suggests that the infection may be secondary.

Safety, inhibition of platelet aggregation and pharmacokinetics of Fab'2 fragments of the anti-glycoprotein IIb-IIIa monoclonal antibody FRaMon in high-risk coronary angioplasty

The purpose of the study was to evaluate safety, effects on platelet aggregation and pharmacokinetics of F(ab')(2) fragments of anti-glycoprotein (GP) IIb-IIIa murine monoclonal antibody FRaMon (F(ab')(2) FRaMon) upon its intravenous administration in patients undergoing high-risk coronary angioplasty. Patients were treated before angioplasty with F(ab')(2) FRaMon at 0.2 mg/kg (n = 17) and 0.25 mg/kg (n = 12) bolus or with abciximab at 0.25 mg/kg bolus + 12 h infusion at 0.125 microg/kg per min (n = 29). F(ab')(2) FRaMon at both doses decreased platelet aggregation induced by 20 microM ADP to <10, <20, <40 and <70% of the predrug level at 1, 12, 24 and 72 h after injection, respectively. No significant differences were observed between F(ab')(2) FRaMon and abciximab antiaggregatory effects. In none of the patients did F(ab')(2) FRaMon cause allergic reactions, major bleedings or deep thrombocytopenia. Antibodies against F(ab')(2) FRaMon were detected in one patient. Free F(ab')(2) FRaMon was cleared from plasma within 12 h, while platelet-bound preparation occupied >95, 70-80 and 40-50% of GP IIb-IIIa at 1 and 12-24 h and 3 days after injection, respectively. Thrombotic complications within the first month after angioplasty in groups treated with F(ab')(2) FRaMon and abciximab were observed in one and two patients, respectively. The data obtained have shown that F(ab')(2) FRaMon at bolus administration to patients undergoing coronary angioplasty caused no serious side effects and at comparative dosage inhibited platelet aggregation with the same efficacy as abciximab at bolus + infusion administration.

[Genoprotective human blood activity and its mechanisms]

Anticlastogenic properties of plasma and proteins (albumin and gamma-globulin) of the human blood were studied using seeds of Crepis capillaris (chromosome aberration assay). Antimutagen p-amino-benzoic acid was used as a comparative reagent. Anticlastogenic activity dependent of processing conditions of the biosubstrate used; for the pre-processing and combined processing anticlastogenic effect was higher than for post-processing, the processing properties of the blood being higher than those of the blood proteins. Anticlastogenic potential of biosubstrates did not depend on mutation inductor. Complex-formimg properties of plasma and blood albumen have been revealed using spectrop-hotometry through the substantial spectral displacement--relative to the expected spectrum--for the mixture of biosubstrata and mutagens. Using chemoluminescence, all plasma, albumin and gamma-globulin concentrations have been shown to enhance generation of hydroxyl radical of the Fenton reagent, especially for albumin in 1.0 g/l concentration. The general trend for all experiments was that the said substances diminished the stimulating effect as their concentrations grew. Peroxidation of yolk lipoproteids showed that only high concentrations of blood's plasma and albumen have antioxidizing properties. gamma-Globulin did not reveal any ability to inhibit lipid peroxidation of yolk lipoproteids. Complex-forming mechanisms of blood's albumen and antioxidizing property of human plasma and proteins have been proved to form the blood's anticlastogenic potential.

Evidence of ehrlichiosis agents found in ticks (Acari: Ixodidae) collected from migratory birds

Two Ehrlichia pathogens were found in immature Ixodes ricinus (L.) ticks collected from migratory passerine birds in the Curonian Spit area of the Baltic Region of Russia (Kaliningrad enclave). During the spring and fall of 2000, 1,606 passerine birds (eight species) were collected; 6.8% of them (110/1,606) were infested by ticks, and 51.8% (57/110) of tick clusters contained various human pathogenic microorganisms. Human monocytic ehrlichiosis (HME) and human granulocytic ehrlichiosis (HGE) agents were found in 14% (8/57) of cases. Borrelia afzelii, Borrelia garinii, and Borrelia burgdorferi sensu stricto were found in 92.9% (53/57) of the ticks. In five out of eight cases, infection of both Ehrlichia and Borrelia were obtained. In one case, a single nymph contained HME, B. afzelii, and B. garinii. Borrelia burgdorferi s.s. and B. afzelii were found together in one pool of four nymphs and one larva. All agents were identified using polymerase chain reaction and species-specific primers. In 8.8% of the ticks collected from birds in the fall and 22% in the spring, pathogens were isolated from attached co-feeding nymphs and larvae. These data demonstrate that Ehrlichia exchange could occur between co-feeding ticks on animals without systemic infection.

[Detection of the genotypic heterogeneity of Ixodes persulcatus Schulze (Acari: Ixodidae) of the North-West region of Russia and characteristics of distribution of tick-borne pathogens causing Lyme disease and Ehrlichia infections in various genotypes]

The heterogeneity of the Ixodes persulcatus population in the vicinity of Saint Petersburg was estimated by using malate dehydrogenase (MDH) isoenzyme. There are six MDH genotypes carrying 3 alleles in the Ixodes persulcatus population. The prevalence of Borrelia and Ehrlichia species in the study genotypes was analyzed. There was a difference in the prevalence and intensity of infection. The greatest abundance of Borrelia was described in the genotypes to Genogroup 1 (with allele 1). Among them, heterozygous ticks were most intensively infected. Polymerase chain reaction identified species pathogenic for man. These included 3 species of Borrelia: B. afzelii, B. garinii, and B. burgdorferi sensu stricto and 2 species of Ehrlichia muris and HGE agent. The author are the first to describe HGE agent and B. burgdorfei ss encountered in Russia.

[Comparison of cytogenic response of human lymphocytes to in vivo and in vitro exposure to low doses of gamma-rays. Unstable chromosomal exchanges detected by FPG techniques]

On peripheral lymphocytes of eight cancer patients undergone whole-body therapeutic irradiation (at daily dose of 10 cGy up to total dose of 50 cGy of 60Co gamma-rays) the dose-response of unstable chromosome exchanges (dicentrics and centric rings) was studied. This dose response fitted well linear function. The lower slope of dose-response curve was found for in vivo irradiated lymphocytes as compared to the dose response curve obtained for in vitro irradiated lymphocytes of the same patients. This finding seems to provide evidence that in case of protracted irradiation of individuals an absorbed dose could be underestimated if for biological dosimetry an in vitro dose response curve for unstable chromosome aberrations is used as referent one.