Pulsatile Features of Major Arteries in Rats during Hypotension Caused by Acute Blood Loss.

The study examined the modes of pulsations of the femoral and carotid arteries of rats in situ (n=14) during acute blood loss, which sequentially caused a deep BP drop, cardiac and respiration arrest, and termination of ECG signals. When BP dropped to 19 (13; 26) mm Hg, the mechanosensitivity of passively pulsing arteries determined by the ratio of the swing range of electroimpedance oscillations of arterial segment to pulse pressure increased by 3.2 (2 ; 4) times (p<0.05). During the decrease of BP to the threshold value of 13 (8; 15) mm Hg, the arterial pulsing mode changed from passive to intermediate and then to the active one characterized by constriction of arterial segment in response to systolic elevation of BP. After cardiac arrest and BP drop almost to zero, the arterial pulsing switched to autonomic rhythmical vasomotions with the rate, which was greater than the frequency of still sustained QRS pulses of ECG. The observed phenomena are explained by transarterial hypotensive transition hypothesis, which argues that peculiarities of pulsations and vasomotions of major arteries during deep BP drop are typical of arterioles under normal or diminished BP. The study refined the hypothesis of "peripheral heart" and its role in hypo- and hypertension.

[Apoptin enhances the oncolytic activity of vaccinia virus].

Chicken anemia virus gene encoding apoptin, a selective killer of cancer cells was synthesized and inserted into vaccinia virus (strain L-IVP) genome. The insertion has replaced major part of the viral C11R gene encoding viral growth factor (VGF), which is important for the virulence. The recombinant virus VVdGF-ApoS24/2 was obtained through the transient dominant selection technique with the use of puromycin resistance gene as the selective marker. The expression apoptin gene from a synthetic early-late promoter of vaccinia virus effectively provides accumulation of the protein in the cells infected with the VVdGF-ApoS24/2 virus. Despite the presence of virus growth factor signal peptide at apoptin N-terminal secretion of the recombinant protein into culture medium did not occur. The recombinant virus VVdGF-ApoS24/2 was found to have a significantly greater selective lyticactivity on human cancer cell lines (A549, A431, U87MG, RD and MCF7) as compared with the parent strain L-IVP and its variant VVdGF2/6 with the deletion of the C11R gene. The results suggest that the use of apoptin represents a promising approach for improving the natural anticancer activities of vaccinia virus.

Rhythmic oscillations of human penile bioimpedance in healthy individuals and in patients with vascular erectile dysfunction.

Small variations of electric impedance (bioimpedance) of human penis were examined in healthy volunteers and in patients with vascular erectile dysfunction (ED). The harmonic analysis revealed rhythmic oscillations of penile bioimpedance at frequencies corresponding to the heart and respiration rates and Mayer wave (0.1 Hz) and to multiple frequencies (harmonics) of the respiratory and cardiac oscillations. In normal penile bioimpedance spectrum, the Mayer and respiratory peaks were several times higher than the first cardiac (pulsatile) harmonic indicating neurogenic origin of rhythmic bioimpedance variations in the whole penis. The most of healthy individuals (78%) demonstrated the cardiac harmonics at the frequency range of 4-7 Hz that violated the monotone decrement of the pulsatile harmonic series suggesting the resonant character of oscillations of the penile arteries at this "near" frequency range. In contrast to stable 1-4 cardiac harmonics, the amplitudes of the near-range resonant harmonics could vary during few minutes suggesting a causal relation of the corresponding bioimpedance oscillations with the varying vascular tone in penile arteries. The most patients (89%) with vascular ED demonstrated not only the first 1-4 monotonically decrementing harmonics and the near-resonant ones, but also the stable cardiac harmonics at the "far" frequency range of 8-14 Hz that also disturbed the monotonic character of the cardiac harmonic series indicating the sclerotic alterations in regional arteries. In ED patients, insignificant decrease of the initial cardiac harmonics C1-C3 in comparison with the norm was accompanied by pronounced and significant decrease of the respiratory R1 and Mayer M1 peaks. The study showed that the far-frequency bioimpedance resonances at the range of 8-14 Hz and dramatic drop of Mayer and respiratory peaks are the diagnostic signs of vascular ED independent on the accompanying hormonal or neurogenic disorders.

[Hydrodynamic method for diagnosing impaired patency of the lacrimal tract].

A hydrodynamic method has been developed, which is based on measurement of the pressure of a certain amount of the fluid passing through the patient's lacrimal tract for a given period. Pressures were determined in 194 healthy volunteers (338 eyes). Three hundred and seventy-six patients (752 eyes) with impaired lacrimation were examined. The examinations have shown that the method provides a way of objectively defining the degree of dacryostenosis, which makes it possible to further use adequate therapy and to monitor its efficiency.

[Difficulties in evaluating the efficacy of antiplatelet therapy in clinical practice].

AIM: To evaluate platelet activity changes in patients with coronary artery disease (CAD) treated with aspirin, clopidogrel and combination of these drugs; to estimate the rate of resistance of CAD patients to antiplatelet treatment. MATERIAL AND METHODS: 199 patients with stable CAD were included in the study. Of them, 83 were given aspirin, 46 received clopidogrel, 34--double antiplatelet therapy (both aspirin and clopidogrel). The trial also studied an additional group of 18 CAD patients on double antiplatelet therapy who had hemorrhages. The control group consisted of 25 healthy volunteers. Platelet aggregation was measured both by a mean size of aggregates (MSA) and light transmission (LTM, Born method) using BIOLA platelet aggregation analyzer. A platelet shape, leukocyte-platelet aggregates (LPA) and erythrocyte-platelet aggregates (EPA) in the whole blood were studied using scanning electron microscopy. The levels of IL-6 and sVCAM were also measured. RESULTS: It was found that 59.8% patients with CAD had high platelet reactivity revealed in 94.9% of cases by measuring spontaneous and induced by 0.1 mcM ADP platelet aggregation. LTM revealed increased platelet reactivity only in 10.7% patients. Resistance to aspirin correlated with the presence of LTA (r = 0.629, p = 0.0001) and the number of large "reticulated" platelets (r = 0.334, p = 0.001). Low platelet reactivity was associated with the presence of circulating EPA (r = -0.362, p = 0.008). Administration of clopidogrel did not decrease platelet reactivity to normal levels in 34.7% patients which correlated with the presence of LPA and EPA. In 83.3% patients with hemorrhages platelet aggregation, induced by 5.0 mcM, ADP was dramatically decreased. CONCLUSION: Resistance to antiplatelet therapy is related to platelet heterogeneity, the presence of inflammation and state of erythrocytes. LT is capable to reveal only a part of patients resistant to antiplatelet drugs. To fully identify these patients, it is necessary to register spontaneous platelet aggregation and aggregation induced by low doses of ADP. Redundant inhibition of platelet reactivity could be the cause of hemorrhagic events.

[Molecular characteristics of testosterone binding globulin and analysis of their regulation].

Molecular characteristics of testosterone binding globulin (TeBG) were investigated in microaliquots of human serum samples using 3H-5-alpha-dihydrotestosterone radioligand assays. Under experimental conditions used TeBG demonstrated high conformational plasticity and ability to adopt three conformational states (olygo-, di-, and monomer) with different functional activities. Using alipidspolyene complex from basidiomycete Laetiporus sulphureus we demonstrate a novel effective pharmacological correction of the TeBG characteristics.

[The role of initial state of adrenal cortex in external irradiation effects upon its structure, function and androgen-receptor interactions].

We studied morphological-biochemical time-course reactions of adrenal cortex and hormonal function of testicles after combined or separate actions of external radiation exposure (1.0 Gy at 7.8 x 10(-4) Gy/sec) and prolonged (12-, 32 days) subcutaneous corticosterone injections (10 mg/kg/animal) in 2-3-month old male rats. Both variants with exogenous hormone depressed endogenous glucocorticoid production and evolved acute structure-functional adrenal gland cortex deficiency. Radiocensitivity of the gland at the experimental conditions was increased. Simultaneously the aggravation of adrenal cortex functional activity accompanied with hypogonadism and depressed reproductive potential of male rats, accessed by means of androgen status and androgenspecific (transporting and receptional) proteins characteristics as sensitive molecular markers of an animal possible fecundity.

[Cooperative characteristics of androgen receptors]. / Izuchenie kooperativnykh kharakteristik retseptora androgenov.

Molecular characteristics of the androgen receptor (AR) from 6-months old albino rat testes were studied. Using radioligand methods, gel filtration on Toyopearl HW-55F column and analyses of specific testicular cytosol 5-alpha-dihydrotestosterone binding in Scatchard and Hill plots it was shown that functional androgen receptor complexes (ARC's) are dimers exhibiting positive cooperativity during hormone ligand binding. The cooperative properties of AR were stable not only at 4 degrees C (Hill coefficient = 2.11) but also at physiological temperature of 36 degrees C (Hill coefficient = 1.95). Presence of Na2MoO4 x 2H2O (10 mM) and/or dilution of cytosols reduced Hill coefficient to 1.03. Addition of morning (but not afternoon) blood sera microquantities (1:20) to monomerized AR preparations resulted in the AR dimerization and restoration of their positive cooperative properties for hormone binding. The effect of morning sera persisted through their pretreatment (15-h at 4 degrees C) with suspensions of 2.5% dextran coated charcoal. Sera from 28-months old rats lacked AR dimerizing activity.

[Effects of radiation-ecological conditions and experimental hyperthyroid states on indicators of testis and prostate androgen receptors in rats]. / Vliianie radioékologicheskoi obstanovki i éksperimental'nogo gipertireoidnogo sostoianiia na pokazateli retseptsii androgenov v semennikakh i predstatel'noi zheleze krys.

Dose-dependent changes of the molecular characteristics on androgen receptor (AR) systems in gonads of male rats were studied at experimental L-thyroxine-induced states after low doses irradiation exposures in different reference points of 10-km Chernobyl zone. The data obtained suggest a generalized working mechanism of "oscillatorous changes" for contents, affinities and cooperative properties of AR to its natural ligands as a "mirror" reflecting some adaptational reactions in target cells that modulates their androgen-controlled biochemical activity.

[Determination of the activity of Willebrand's factor by laser analyzer of platelet aggregation]. / Opredelenie aktivnosti faktora Villebranda pri pomoshchi lazernogo analizatora agregatsii trombotsitov.

A modification of von Willebrand' factor/ristocetin cofactor activity test is proposed. Agglutination of formalin-treated platelets is monitored in the aggregation analyzer from changes in the light transmission in the specimen. The test is sensitive and reproducible. It is intended for clinical laboratories to be used in patients with hematological diseases and the endotheliopathy syndrome of different etiology.

[Effects of prolonged low-dose gamma irradiation on testes of rats]. / Posledstviia prolongirovannogo nizkodozovogo gamma-oblucheniia v semennikakh krys.

Dose-dependent characteristics of rat testicular cytosol androgen reception at varied terms after prolonged whole-body gamma-irradiation (0.1, 0.25 and 0.5 Gy at dose rate of 5.83 x 10(-7) Gy/s) coupled with an electron microscopy morphological characteristics of Sertoli cells. Leydig's cells and other populations of testicular cells, were examined. Analysis of the data obtained suggests the existence of gamma-sensor in brain of mammals, that involved on hypothalamic-pituitary-testicular levels in realisation of radiation stress suppression of Sertoli cell functions at a relatively "low" (0.1-0.5 Gy) doses by means of hypothalamic releasing factors and, therefore pituitary gonadotropins hypersecretion.

[The functional characteristics of the thrombocytes in patients with hypertension and "silent" myocardial ischemia]. / Funktsional'nye kharakteristiki trombotsitov u bol'nykh gipertonicheskoi bolezn'iu i s "nemoi" ishemiei miokarda.

Functional platelet characteristics were studied in hypertensive subjects having episodes of silent myocardial ischemia. A total of 36 patients with essential hypertension (EH) stage II (WHO criteria, 1979) underwent echocardiography and 24-h ECG monitoring. Platelet aggregation induced by adenosine diphosphate was assessed by laser aggregation analyzer. It is demonstrated that platelet aggregation in EH patients with silent ischemia was increased 5-fold as compared to healthy subjects and 2-fold versus EH patients without ischemia. No significant differences existed between the two groups by such parameters as systolic or diastolic pressure and left ventricular myocardial mass. An involvement of elevated platelet aggregation can be suggested in the genesis of coronary insufficiency in EH associated with episodes of silent myocardial ischemia.

[A method for determining individual nifedipine sensitivity in treating hypertension patients]. / Metod opredeleniia individual'noi chuvstvitel'nosti k nifedipinu pri lechenii bol'nykh gipertonicheskoi bolezn'iu.

Nifedipine antihypertensive effect was evaluated in 20 patients with essential hypertension. It was found to depend on pretreatment values of ADP-induced platelet aggregation response. The latter was studied with a new method of laser measurements of the aggregate radius sizes.

Multiple-modified desialylated low density lipoproteins that cause intracellular lipid accumulation. Isolation, fractionation and characterization.

BACKGROUND: The basic differences between sialylated (sialic acid rich) and desialylated (sialic acid poor) human low density lipoproteins (LDL) are not fully defined. It is not known whether there are any differences in the LDL composition of coronary atherosclerosis patients and healthy individuals. EXPERIMENTAL DESIGN: Sialylated (45 to 94% of total LDL) and desialylated (6 to 55%) LDL were separated by affinity chromatography on Ricinus communis agglutinin-agarose, and their chemical composition and physical properties were examined. RESULTS: Sialic acid contents in sialylated LDL fractions of healthy subjects and patients were the same and 1.5 to 3-fold higher than in desialylated LDL. Desialylated LDL had smaller sizes and greater electrophoretic mobility than sialylated ones. Desialylated, but not sialylated LDL, induced 1.5- to 4-fold accumulation of neutral lipids in human aortic smooth muscle cells and human blood monocytes. Subfractions of desialylated LDL containing lower amount of sialic acid revealed higher ability to accumulate lipids in cultured cells. Desialylated LDL contained lower amounts of cholesteryl esters, free cholesterol and triglycerides as compared with sialylated LDL. On the other hand, concentration of di-, monoglycerides and free fatty acids in desialylated LDL was 2 to 3-fold higher than in sialylated lipoproteins. Desialylated LDL fraction was characterized by lower levels of phosphatidylcholine, sphingomyelin, phosphatidylethanolamine, but higher content of lysophosphatidylcholine. Freshly isolated sialylated and desialylated LDL contained equal amounts of thiobarbituric acid reactive substances, but oxidation of desialylated LDL was more pronounced in presence of Cu(2+)-ions. Desialylated LDL had higher level of oxysterols and lower amounts of vitamin A and E. Content of free amino groups of lysine in desialylated LDL of patients was 2-fold lower than in sialylated LDL. This difference was partially due to masking of amino groups caused by conformational change in the tertiary structure of apolipoprotein, partially to chemical modification of amino groups. When subfractionated by density gradient ultracentrifugation, desialylated LDL was represented by higher density particles than sialylated LDL. Sialic acid content in desialylated LDL subfractions decreased with rise of lipoprotein density. Higher density desialylated LDL and in less extent sialylated LDL contained smaller amounts of free and esterified cholesterol and phospholipids. Only the densest subfractions of desialylated LDL from healthy subjects caused intracellular lipid accumulation. Ability of patients' desialylated LDL to accumulate cholesterol in cells increased with particle density. CONCLUSIONS: Extensive biochemical and biophysical analysis performed in this study shows that desialylated LDL differ from these sialylated LDL in many respects. The LDL of coronary atherosclerosis patients differ from those in healthy individuals in several parameters.

[The effect of iodine-131 on the binding characteristics of sex and thyroid hormones by blood plasma proteins in children with a functional thyroid disorder as a result of the accident at the Chernobyl Atomic Electric Power Station]. / Vliianie ioda-131 na kharakteristiki sviazyvaniia polovykh i tireoidnykh gormonov belkami plazmy krovi u detei s funktsional'nym narusheniem shchitovidnoi zhelezy v rezul'tate avarii na ChAES.

In studying characteristics of specific interaction of estradiol-, testosterone- and thyroid-binding blood globulins with the corresponding ligands in children from Gomel Province with endemic swelling of the thyroid gland (degrees I and II) affected by iodine-131 revealed were a reduced cooperativity in estradiol and T-3 binding and a halved affinity to androgens and thyroids as compared to healthy controls. In addition, there was a drastic decline in the binding capacity of estradiol- and testosterone-binding globulins in the blood plasma. The endemic thyroid gland swelling is supposed to be due to sexual malfunction in teenagers.

Three types of naturally occurring modified lipoproteins induce intracellular lipid accumulation due to lipoprotein aggregation.

Low density lipoprotein (LDL) from patients with coronary atherosclerosis and diabetes mellitus as well as in vitro desialylated LDL, glycosylated LDL, and lipoprotein (a) caused a twofold to fourfold rise in cholesteryl ester in cultured human blood monocytes and intimal smooth muscle cells isolated from normal aorta. Native LDL from healthy subjects failed to induce intracellular lipid accumulation. We have demonstrated by laser correlative photometry and gel filtration chromatography that in vivo and in vitro modified lipoproteins form aggregates under cell culture conditions. The degree of modified lipoprotein aggregation directly correlated with the ability of these lipoproteins to elevate the cholesteryl ester content of cultured cells. Modified lipoprotein aggregates isolated by gel filtration induced a threefold to fivefold elevation in cellular cholesteryl ester content. Aggregates of 125I-modified LDL were taken up and degraded fivefold to sevenfold more effectively as compared with nonaggregated lipoproteins. The uptake and degradation of 125I-labeled aggregates were strongly inhibited by unlabeled aggregates, latex beads, and cytochalasin B but not by native or acetylated LDL. These data indicate that uptake of lipoprotein aggregates occurred by phagocytosis. Obtained results suggest that modified lipoprotein aggregation may be the key condition for lipid accumulation.

Contractile rabbit aortic smooth muscle cells in culture. Preparation and characterization.

Investigations were conducted to determine whether rabbit aortic smooth muscle cells (SMC) reproduce their essential in situ features in culture. Enzymatically isolated cells in culture were compared with their in situ state in terms of myosin and caldesmon isoform expression, sensitivity to Ca(2+)-mobilizing agonists, and contractility. Protein marker expression was assessed by electrophoresis and quantitative immunoblotting, and intracellular free Ca2+ ([Ca2+]i) measurements were accomplished using indo-1, a Ca(2+)-sensitive fluorescent dye. Contraction of SMC grown on deformable silicone films was monitored optically. Before the onset of cell division (3 to 6 days in culture), SMC still contained significant although decreasing amounts of smooth muscle myosin (SM1 and SM2 isoforms) and they started to express nonmuscle-type myosin. The relative content of 150-kDa caldesmon decreased, whereas the expression of 77-kDa caldesmon increased during this period. In the confluent primary culture (11 days), SM1 was expressed, but 150-kDa caldesmon was hardly detectable. Histamine (10(-5) mol/L), serotonin (10(-6) mol/L), and thrombin (1.5 units/mL) contracted deendothelialized rings of rabbit aorta, but only histamine was able to elevate [Ca2+]i 2.5- to 3-fold and induce reversible contraction of primary nondividing cells. [Ca2+]i elevation in response to histamine was due both to Ca2+ mobilization from intracellular stores and Ca2+ flux across the plasma membrane. After the onset of proliferation, SMC regained the ability to elevate [Ca2+]i in response to serotonin and thrombin but lost the ability to contract. Thus, primary cultured quiescent rabbit aortic SMC (3 to 6 days in culture) retain the essential features of vascular SMC in situ (eg, smooth muscle specific contractile and regulatory proteins, vasoactive hormone sensitivity, and contractility).