[Redox-dependent ferric oxide nanoparticles loaded with doxorubicin and their influence on the functions of mitochondria]

The spectral, fluorescent and functional properties of ferric oxide and ferric hydroxide nanoparticles loaded with doxorubicin and stabilized with citric acid or lysine were studied in comparison with free doxorubicin. Their effect on the opening of calcium-induced mitochondrial pore and the possibility of the controlled release of doxorubicin under the influence of redox stimuli were investigated. The data show that the effect of nanoparticles on mitochondria depends on the type of a stabilizer. The spectral and fluorescence methods used allow us to estimate the presence or absence of free doxorubicin in solution of nanoparticles and the:concentration of bound doxorubicin. It is shown that the dithiotreitol and glutathione increase the amplitude of absorption and fluorescence of doxorubicin during incubation with nanoparticles. It is assumed that this effect may be associated with the reduction of the oxidized iron by thiols with subsequent release of doxorubicin.

[Antitumor and antiproliferative action of the steroidal cytostatic antiestrogen cytestrol acetate on hormone-dependent tumor models]

Cytestrole acetate (CA), in the structure of which the steroidal antiestrogen component is associated with bis-β-cloroethylamino group, exhibits a strong cytotoxic activity against hormone-dependent cancer cell lines (CaOV, HeLa, MCF-7). In doxorubicin-resistant MCF-7 cells, CA potentiates the cytotoxic effect of etoposide and doxorubicin, and the IC50 for CA in these cells is 40 times lower than that for tamoxifen (TAM). In transplantable mice breast adenocarcinoma Ca-755, the therapeutic CA dose is 25 mg/kg when administered subcutaneously in oil solution for 5 days. On the DMBA-induced mammary tumors in rats, CA injected subcutaneously led to partial regressions 4 weeks after treatment in 75% of test rats, whereas TAM produced this effect in 43% of rats. Among various drug forms of CA, the most active were oil solution of CA in gelatin capsules for oral use and liposomal emulsion for intravenous administration, since these forms exhibited the highest values of Ca-755 tumor growth inhibition index (TGI = 97 - 98%).

[Prevention of contrast-induced nephropathy in the context of evidence-based medicine]

The paper considers the mechanisms of development of contrast-induced nephropathy in the use of iodinated radiopaque contrast agents (RCAs), as well as the criteria of their assessment. It gives different existing recommendations for prevention of the nephrotoxic effects of RCAs.

[Bolus contrast-enhanced multislice spiral computed tomography of the chest: new possibilities in the diagnosis of lung diseases]

OBJECTIVE

To elaborate optimal programs for bolus contrast-enhanced multislice spiral computed tomography (MSCT) of the chest for different types of tomographic scanners and in some lung diseases.

MATERIAL AND METHODS

Contrast-enhanced MSCT findings were analyzed in 637 patients, 536 of whom presented with a focal pathological process in the lung and 101 had pulmonary emphysema.

RESULTS

There is evidence proving the expedience of using the contrast medium iopromide that has an optimal balance between the high concentration of iodine and its excellent tolerance due to low osmolarity and low viscosity.

CONCLUSION

Intravenous bolus contrast-enhancement using an automated injector can visualize chest organs in different phases of contrast enhancement, by significantly improving the quality of diagnosis and achieving 100% disease diagnosis comparable with its morphological diagnosis.

[Relative binding activity of dydrogesterone with blood mononuclear cells progesterone receptors of women included in the IVF program]

It has been shown that specific binding of dydrogesterone with progesterone receptors in blood mononuclear cells of the patients included in the programs of in vitro fertilization, varies from 0 to 298%, thus at 38% of women dydrogesterone concedes to a progesterone in the competition for receptors of a progesterone, and 62%--exceed. The revealed variations of specific binding dydrogesterone with receptors of a progesterone are a reserve of increase of efficiency of auxiliary reproductive technology at the expense of individual selection of hormonal agents.

[Estimating ability of dihydroquercetin to inhibit oxidation of fibrinogen by ozone]

The ability of dihydroquercetin to inhibit the oxidation of fibrinogen has been evaluated. It is established that dihydroquercetin inhibits oxidation of fibrinogen by ozone, thus preventing oxidative modification of fibrinogen and preserving its functional activity.

[Effect of steroid hormones on production of reactive oxygen species in mitochondria]

Among the targets of the steroid hormones are mitochondria, which as the main source of reactive oxygen species (ROS) in the cell play a central role in the development of various pathologies. We studied the effect of progesterone and its synthetic analogues on mitochondrial ROS production. It was found that progesterone activates the formation of superoxide anion and hydrogen peroxide in mitochondria during oxidation of complex I substrates of the respiratory chain and exerts no influence on production of ROS during oxidation of succinate, complex II substrate of the respiratory chain. Synthetic analogues of progesterone - medroxyprogesterone acetate, buterol, acetomepregenol, megestrol acetate, have different effects on ROS production, depending on their chemical structure. By the effectiveness of impact on ROS production in mitochondria all the steroids tested can be classified in the descending order as follows: progesterone > buterol > or = atsetomepregenol > medroxyprogesterone acetate > megestrol acetate. Activation of ROS production by progesterone and buterol has different mechanisms: progesterone acts as an inhibitor of NAD-dependent respiration, while buterol and acetomepregenol form noncovalently associated complexes by hydrogen bonds between the ester carbonyl at C3 and SH-groups of the respective targets.

[Antihypertensive and neuroprotective activity of quercetin and its derivatives]

Data available in the literature on the pharmacological activity of quercetin and its derivatives, which possess various biological properties including antihypertensive and neurotropic activity, are reviewed. The mechanisms of these effects and results of clinical trials are considered and prospects for the clinical use of quercetin and its derivatives are discussed.

[Estrogens and brain]

Recent data upon molecular mechanisms of pleiotropic action of estrogens in human brain is presented in the article. Given detailed descriptions of properties of classical and membrane bound estradiol receptors, that maintain gene expression regulation, modulation of neurotransmittent systems and signal cascade activation in neuronal cells. Data upon regional distribution of estradiol receptor subtypes in the brain, their participation in main cell population function control (including progenitor cells) is given. Special attention is paid to estrogen participation in neurogenesis, inflammation and apoptosis regulation in central nervous system; in the control of formation and functioning of cerebral vessels.

[Empiric treatment of pyelonephritis]

The article analyses the most typical clinical situations in empirical treatment of pyelonephritis including situations with comorbid severe diseases: decompensated diabetes mellitus, chronic renal failure, HIV-infection. Choice of antibacterial medicines for empiric treatment of pyelonephritis is based on the results of the latest studies of antibioticoresistance of pyelonephritis pathogens as well as on specific features of pharmacokinetics and pharmacodynamics of antibacterial drugs.

[Experimental study of indium-111 labeled octreotide application for radionuclide diagnostics of tumors with high expression of somatostatin receptors]

We have studied the possibility of using octreoitid labeled by indium-111 for radionuclide diagnostics of neoplasms with high expression of somatostatin receptors. It has been established that, using experiments with cell cultures, it is possible to predict the application of 111In-labeled octreotid and determine time intervals for the best visualization of tumors. Indium-111-labeled octreotid accumulation in animals with transferred B16 tumor (pigment melanoma) shows evidence for the opportunity of using this substance as radiopharmaceutical medium for tumor diagnostics.

[Aggregation, deformation and morphology of erythrocytes in patients with ischemic heart disease after injection of ioversol, iodixanol and gadobutrol]

In patients with ischemic heart disease, the administration of contrast agents iodixanol, ioversol and gadobutrol improves (due to the effect of dilution) the aggregation of erythrocytes in vivo, but does not change their deformation ability and the percentage of different morphological forms of erythrocytes (discocytes and ehinocytes) in the blood. The effect of gadobutrol on the aggregation of erythrocytes is characterized by more expressed antiaggregant effect due special molecular properties of this drug.

[Antiproliferative and antioxidant activity of new dihydroquercetin derivatives]

Effect of nine new derivatives of dihydroquercetin (taxifolin) on the viability of cultivated normal and tumor cells, their antioxidant activity, and interconnection of the antioxidant activity with the chemical structure have been studied. Among these dihydroquercetin derivatives, the maximum antiproliferative activity on the model of rat fibroblast culture exhibited KN-2, KN-4, KN-7, and KN-8 compounds, while KN-7 and KN-8 compounds also showed maximum activity on the model of MCF-7 tumor cell culture (human breast cancer). The maximum general antioxidant activity was observed for the native dihydroquercetin and KN-8 compound. There is a strong correlation (with a correlation coefficient of 0.93) between the antiproliferative effects of dihydroquercetin derivatives on murine skin fibroblasts and MCF-7 cells (human breast cancer).

[Pharmacological properties of complex iron oxide nanoparticles entering in magnetic resonance tomography contrast agent]

A colloidal solution of iron oxide nanoparticles has been obtained that ensures an increase in the accuracy of diagnostic information from magnetic resonance tomography (MRT) due to the acceleration of proton relaxation in tissues, which improves the contrast of T1- and T2-weighed images. Improved visualization of small vessels in rat brain has been observed after intravenous injection of 0.1 ml solution containing 5.0 mg of contrasting iron nanoparticles. The paramagnetic properties of iron oxide nanoparticles were studied by the method of proton relaxation, and their size was determined by the method of transmission electron microscopy. The toxic properties ofnanoparticles were determined by their effect on cultured HeLa cells (MTT test). It is recommended to use a colloidal solution of superparamagnetic nanoparticles (size, 8.2 nm) for obtaining a pharmaceutical form of the new magnetic-resonance contrast medium Ferotrast.

[Current status of antibiotic resistance of pyelonephritis causing pathogens]

The article gives the analysis of frequent clinical situations arising in empiric therapy of pyelonephritis alone and accompanied with other severe diseases such as decompensated diabetes mellitus, chronic renal insufficiency, HIV infection. The choice of antibacterial drugs for empiric therapy of pyelonephritis is based on the results of the tests for antibiotic resistance of pyelonephritis causing agents, pharmacokinetic and pharmacodynamic studies. Present-day standards and recommendations of leading centers of pyelonephritis empiric therapy are reviewed.

[Molecular mechanisms of cytostatic and chemosensitizing action of gestagens]

In this study cytostatic and chemosensitizing actions of gestagens are described. Cytostatic mechanisms can be divided into estrogen-mediated and independent ones. The former include down-regulation of estrogen receptors, induction of 17?-hydroxysteroid dehydrogenase and estron sulfotransferase. The latter are MAP-kinase inhibition, induction of cell differentiation and apoptosis. Chemosensitization by gestagens is due to inhibition of P-glycoprotein, GST and MRP. Another putative chemosensitization mechanisms involves mitochondrial transition pore (MTP), at least for such gestagens as buterol and acetomepregenol. Elucidation of common mechanisms of MTP and MDR regulation and the possible role of MTP in chemosensitization is a new direction of investigations into the action of steroid hormones.

[Deformation properties of human erythrocytes in the presence of x-ray contrast agents]

It is established that the x-ray contrast agents urografin (76 %), omnipaque-300, optiray-350, ultravist-300, and visipaque-270 produce a dose-dependent decrease in the deformation properties of human erythrocytes in vitro. The degree of manifestation of this negative influence increases with the osmotic activity of agents in the following order: visipaque = ultravist < or = omnipaque < or = optiray < urografin. The effect of these x-ray contrast agents on the deformation of erythrocytes is reversible. Erythrocytes restore their normal deformation properties upon removal of the osmotic pressure induced by the x-ray contrast agents.

[Effect of x-ray contrast agents on the thromboresistant properties of vascular walls]

It is established that the x-ray contrast agents urografin, omnipak, and ultravist produce a dose-dependent decrease in the thromboresistant properties of vascular walls in experimental rats. This effect is determined by the individual properties of substances rater than by their belonging to a certain class of ionic or nonionic compounds. Preliminary administration of n3-polyunsaturated fatty acids from fish oil offers a significant protection against the negative action of x-ray contrast agents and retains the antiaggregant activity of the vessel wall intima.

[Proliferative activity of rat skin fibroblasts under the action of glucocorticoids and gestagens]

Temporal and concentration dependences of the effect of the new synthetic gestagen 17alpha-acetoxy-3beta-butanoyloxy-6-methyl-pregna-4,6-dien-20-one (ABMP) and reference glucocorticoids (dexamethasone and hydrocortisone) and progesterone on the proliferative activity of rat skin fibroblasts were examined using the MTT assay. The results demonstrated that ABMP along with glucocorticoids produced an antiproliferative action against fibroblasts, with the maximum (38%) suppression of the metabolic activity of cells observed after 5-day incubation at a drug concentration of 10(-5) M.

[Interaction of the new gestagen compound 17alpha-acetoxy-3beta-butanoyloxy-6-methylpregna-4,6-dien-20-one with human blood proteins and calf embryo serum]

Molecular mechanisms of sex hormones (progesterone, medroxyprogesterone acetate (MPA), and new synthetic gestagen 17alpha-acetoxy-3beta-butanoyloxy-6-methylpregna-4,6-dien-20-on (ABMP) with human serum albumin, globulins, and calf embryo serum were studied. The binding of ABMP to albumin and progesterone-binding proteins were investigated using spectroscopic techniques (with the use of 1-anilino-8-naphthalenesulfonate as fluorescent probe) and radiolabeled progesterone, (either progesteron or MPA as comparative progestines). There is no difference between the non-specific binding of ABMP, progesterone, and MPA, but the ABMP binding is much smaller as compared to the binding of progestines, so that the new progestine ABMP will produce a more effective action on the target tissue than comparative progestines.

[A new Russian gestagen with anticancer activity]

The authors present results obtained in a complex study of 17alpha-acetoxy-3beta-butanoyloxy-6-methyl-pregna-4,6-dien-20-on (ABMP). ABMP was shown to differ from existing analogues by high gestagen activity and prolonged action. The substance does not possess androgenic or mineralocorticoid activity, is not toxic when used in high doses, and possesses significant cytostatic and chemiosensitizing activity. These properties of ABMP demonstrate that the substance should be studied in clinical setting as a gestagen with anticancer and chemiosensitizing activity for further application to therapy of hyperplastic processes in the female genital system and tumors that are sensitive to female sex hormones.

[Genomic and extragenomic mechanisms of antiglucocorticoid action of gestagens on thymocytes]

Effects of a new synthetic progesterone derivative 17a-acetoxy-3b-butanoyloxy-6-methyl-pregna-4,6-dien-20-one (ABMP) and the reference gestagen preparations on the rat thymus were evaluated by the degree of variation of the intracellular levels of calcium and cAMP, 3H-uridine inclusion into RNA, thymocyte viability, and thymus mass. It is shown that gestagens can produce antiglucocorticoid action on thymocytes, this activity being most pronounced in the case of ABMP.

[Effects of ionic and non-ionic roentgen-contrast media upon ex vivo hemostasis in rabbits]

The influence of ionic and non-ionic contrast media on the ex vivo hemostasis in rabbits was studied for ionic urografin (76 %), non-ionic ultravist-300, and non-ionic omnipaque-300 intravenously injected in medium and high doses (1.5 ml/kg and 3.0 ml/kg, respectively). Ionic urografin (1.5 ml/kg) almost did not influence the level of hemostasis ex vivo. Non-ionic contrast media (ultravist and omnipaque) in the medium diagnostic dose (1.5 ml/kg) activated the hemostasis, the effect being much more pronounced in the case of omnipaque. Dose-dependent action was observed for both ionic and non-ionic contrast media.

[The use of magnetic resonance contrast agents for selective digital subtraction angiography and computed tomography with contrast enhancement]

Allergy to iodine-containing contrast agents is the main contraindication for angiographic examinations of patients. This paper reviews the works of Russian and foreign specialists describing an experience gained with the use of magnetic resonance gadolinium-containing agents possessing radioabsorption properties for digital subtraction angiography and CT, angiography. The authors provide a comparative evaluation of the efficacy of the use of magnetic resonance contrast agents with varying gadolinium concentration. The conclusion is drawn about the comparable diagnostic accuracy of angiograms obtained with the aid of nonionic iodinated contrast agents and monomolar gadolinium-containing contrast agents (Gadovist 1.0).

[Expanding the possibilities of using biphosphonates for prophylaxis and treatment of osteal complications in malignant metastasis]

New results concerning the mechanisms of biphosphonate action on malignant metastasis are described, which justify an increase in the use of biphosphonates not only for the treatment of malignancies, but for prophylaxis of malignant neoplasm development as well. Data on the relationship between the pharmacological effect of biphosphonates and their chemical structure are presented. It is emphasized that clodronate, which is most thoroughly investigated drug of this group, can be more frequently used in clinics for the treatment and prophylaxis of osteal complications in cases of breast cancer.

[Antiaggregant and antioxidant activity of estradiol and tamoxifen]

Tamoxifen did not influence the human platelet aggregation in vitro, while estradiol at a concentration of 10(-6) M inhibited the aggregation of human thrombocytes induced by ADP, serotonin + adrenaline, and adrenaline (epinephrine) by 14.7, 12.5, and 16.6%, respectively. Estradiol introduced in the range of effective concentrations from 10(-8) to 10(-4) M inhibited lipid peroxidation, while tamoxifen produced this effect only at a concentration of 10(-4) M. There was a correlation between the antiaggregant activity and antioxidant properties of estradiol.

[Antitumor activity of the new gestagen 17alpha-acetoxy-3beta-butanoyloxy-6-methyl-pregna-4,6-dien-20-one]

Antitumor activity of a new highly active promising gestagen 17alpha-acetoxy-3beta-butanoyloxy-6-methyl-pregna-4,6-dien-20-one (butagest) was studied in mice with model cervical carcinoma (RShM-5). The reference drug was medroxyprogesteron acetate (MPA, Depo Provera) used in clinics. The new preparation introduced perorally in a dose of 1 mg per mice inhibited the model tumor growth by 73%, which was 18% (p < 0.01) more effective than the action of the reference drug MPA. The effect of the new gestagen was also studied in vitro with respect to human breast carcinoma of the MCF-7 line and human cervical carcinoma HeLa. The viability of the tumor cells was studied during a 6-day incubation with the drug at a concentration of 10(-7)-10(-5) M (MTT test). The reference compounds were progesterone and MPA. These drugs suppressed the growth of both MCF-7 and, in higher concentrations, of HeLa. Butagest inhibited the growth of HeLa in all concentrations. Thus, the new gestagen 17alpha-acetoxy-3beta-butanoyloxy-6-methyl-pregna-4,6-dien-20-one is capable of suppressing the viability of human breast carcinoma and human cervical carcinoma, being comparable or even more effective than the reference drugs.

[Hemodynamic effects of contrast substances as dependent on their viscosity and osmolality]

This paper analyzes the current information on the role of viscosity and osmolality of the solutions of iodine-containing contrast substances used in angiology, in microcirculatory disorders due to angiography. Provides the data that confirm blood flow deceleration and the development of hypoxia during the use of more viscous dimeric substances. It is concluded that the change in microcirculation is an important indicator of the safety of modern iodine-containing contrast-diagnostic agents, among which the monomeric non-ionic substances possess an optimal combination of the high contrast and low osmolality.

[Anti-arrhythmia activity of estradiol valerate and estradiol nitrate]

Estradiol valerate and estradiol nitrate exhibit significant antiarrhythmic activity of on the aconitine arrhythmia model in rats. In both cases, the maximum effect was observed in a dose of 0.5 mg/kg.

[Radiocontrast properties of the emulsion of the perfluoroorganic compound lipobrom]

X-ray contrast properties of the new perfluoroorganic emulsion lipobrom were studied in comparison to those of a traditional clinical Roentgen diagnostic agents omnnipaque and ultravist and the well-known blood substitute perftoran. The x-ray patterns were evaluated by a computer morphodensitometry technique.

[Lowering of nephropathy risk during angiography procedure. What are choice criteria for the radiocontrast media?]

The paper analyses current data of monomer and dimmer iodine-containing radiocontrast agents used for diagnosis of cardiovascular diseases and radiovascular interventions. Considering the risk factors of nephropathy as the most common and threatening complication of radiocontrast agents the authors conclude that non-ionic monomers are the most advisable as they demonstrate optimal balance of viscosity, water solubility, osmolality and diagnostic effectiveness.

[The effect of diagnostic contrast media on the activity of lactate dehydrogenase in rat blood]

It is shows that the diagnostic Roentgen contrast media (RCM) in a dose of 2.0 g iodine/kg increase the activity of lactate dehydrogenase in rat blood, the effect decreasing in the following order: iodamide > bilignost > triombrast > peritrast > melitrast > omnipaque > hexabrix. At the same time, the RCM in a dose of 0.5 g iodine/kg (iodine concentration, 0.03-30 mg/ml) and gadolinium-containing magnetic-resonance contrast media (MRCM) in a dose of 0.1 mM/kg (gadolinium concentration, 0.2-1 mg/ml) inhibit the enzyme, the effect decreasing in the following order: bilignost = iodamide = triombrast = peritrast > hexabrix > omnipaque = melitrast = ultravist = magnevist = dipentast. The mechanism of action of the contrast media on the LDH activity was studied and it was found that changes in the enzyme activity is correlated with the toxicity (LD 50) of RCM. The groups of risk from the standpoint of side reactions to the intravenous RCM introduction are determined.

[The dynamics of antigen-antibody complex formation in the presence of iodine-containing diagnostic agents]

A mathematical model is proposed to describe the antigen-antibody complex formation under the immunoassay conditions, which allows the antibody-antigen affinity to be evaluated. In particular, it is established that the dissociation constant of the antigen-antibody complex (for antibodies to a tuberculous Mycobacterium) confidently increases (p > 0.95) in the following sequence of diagnostic kits: omnipak > Ultravist > melitrast > Triombrast. The method suggested for analysis of the influence of xenobiotics upon the antigen-antibody reaction can be used to reveal their possible side effects on the antigen-antibody complex formation in any particular case.

[The effect of x-ray contrast media on the concentration of intracellular calcium in mononuclear cells]

It was shown by the method of fluorescent probes that iodine-containing radiocontrast agents Triombrast > Omnipaque > Ultravist > Melitrast increase the content of intracellular Ca2+ in macrophages of the abdominal cavity of rats. Increase in the entry of Ca2+ from the external environment is the main factor of the change in the intracellular concentration of Ca2+ ions in the macrophages in interaction with radiocontrast agents.