Determining triple half-twist of optical Möbius strips in electromagnetic fields with a non-planar structure.

Polarization ellipses in a nonparaxial field form twisted strips when traced along closed contours around a circular polarization singularity line. We found an analytical expression for the twist number of the strip when the contour is coplanar with the polarization ellipse in its center. Necessary and sufficient conditions for strips having one or three half-twists are found. A set of five parameters of electromagnetic field at the polarization singularity point is found which definitely determines the value of the twist number of the strip.

Prophylactic Admission of an In Vitro Reconstructed Complexes of Human Recombinant Heat Shock Proteins and Melanoma Antigenic Peptides Activates Anti-Melanoma Responses in Mice.

Tumor-derived autologous antigenic peptides when bound to endogenous 70 kDa family heat shock proteins (HSP70) are able to induce effective T-cell responses against tumors. However, efficacy of HSPbased vaccines in clinical practical stand point still has a number of certain limitations including an activation of immune responses against alien non-human HSPs. In this study we reconstructed the complexes of human recombinant HSPs70 (human recombinant HSP70A1B and HSC70 mixture; hrHSPs70) with antigenic lowweight peptides derived from mice B16F10 melanoma cell lysate (PepMCL) in vitro and investigated the prophylactic potential of these complexes to activate anti-tumor immunity in melanoma mouse model. Our results demonstrate that the developed prophylactic vaccine elicits melanoma-specific immune responses and anti-tumor effects against melanoma. These results suggest that hrHSPs70 has capability to reconstitute complexes with peptides obtained from tumor cells lysates in vitro and, therefore, can be used for delivery of multiple antigenic peptides into antigen-presenting cells (APCs) to activate effectors cells. Designed in such a way hrHSPs70-based prophylactic vaccines induce immune responses resulting in a significant efficient prevention of tumor growth and metastases.

[Antiaggregation activity of arachidonic acid conjugates with neurotropic peptides proglyprol and semax].

The influence two original derivatives of a therapeutically important peptide, bearing arachidonic acid residue with semax and proglyprol, upon platelet aggregation have been studied in vitro. It is established that both derivatives, in contrast to the parent peptide, possess moderate anti-aggregant properties and produce a dose-dependent decrease in the interplatelet interaction induced by ADP, epinephrine, and arachidonic acid within the concentration range of 0.018 - 1.8 mM. This activity was more pronounced for arachidonoylsemax in comparison with arachidonoylproglyprol.

[The antiaggregant action of 2-morpholino-5-(thienyl-2)-6-H-1,3,4-thiadiazine in in vitro and ex vivo experiments].

The influence of 2-morpholino-5-(thienyl-2)-6-H-1,3,4-thiadiazine (H-29) on the platelet aggregation has been studied in experiments on donor plasma in vitro. It is established that H-29 causes a decrease in the platelet interaction induced by ADP and arachidonic acid. The influence of H-29 on platelet aggregation was also studied in ex vivo experiments with intravenous and oral administration, and some parameters of plasmatic hemostasis were evaluated.

[Influence of new 1,3,4-thiadiazines on platelet aggregation in vitro and ex vivo].

The influence of new original 1,3,4-thiadiazines on the human platelet aggregation in vitro was studied. All substances inhibited the platelet aggregation induced by both ADP and arachidonic acid. 1,3,4-Thiadiazines L-19, H-30 and L-37 were the most effective inhibitors. Effect of the intravenous injection of L-19 in various doses on platelet aggregation and some parameters of plasmatic hemostasis were studied ex vivo.

[New protein vectors based on an alpha-fetoprotein fragment for targeted DNA delivery into cancer cells].

A human alpha-fetoprotein fragment (AFP) modified with oligocationic homologs of nuclear localization signal was used to construct new target cell-selective DNA-carrier proteins. The new recombinant vectors containing C- or N-terminal polynucleotide-binding domains are able to form stable complexes with single- or double-stranded oligonucleotides and plasmid DNA. Using flow cytometry and fluorescent microscopy, it was shown that such nucleoprotein complexes can be selectively internalized in target cells receptors superexpressing AFP receptors. The results obtained are important both for understanding mechanisms of formation of DNA-protein complexes and for studying their interaction with intracellular molecular targets. The new proteins can be used as a tool for the development of highly selective and efficacious gene-selective antitumour drugs.

Targeted delivery of anti-cancer growth inhibitory peptides derived from human alpha-fetoprotein: review of an International Multi-Center Collaborative Study.

The alpha-fetoprotein derived growth inhibitory peptide (GIP) is a 34-amino acid peptide composed of three biologically active subfragments. GIP-34 and its three constituent segments have been synthesized, purified, and studied for biological activity. The GIP-34 and GIP-8 have been characterized as anticancer therapeutic peptides. An multicenter study was initiated to elucidate the means by which these peptide drugs could be targeted to tumor cells. The study first established which cancer types were specifically targeted by the GIP peptides in both in vitro and in vivo investigations. It was next demonstrated that radiolabeled peptide ((125)I GIP-34) is specifically localized to rodent breast tumors at 24 h post-injection. The radionuclide studies also provided evidence for a proposed cell surface receptor; this was confirmed in a further study using fluorescent-labeled GIP-nanobeads which localized at the plasma membrane of MCF-7 breast cancer cells. Finally, it was readily demonstrated that GIP conjugated to either fluorescein or doxorubicin (DOX) underwent tumor cell uptake; subsequently, DOX-GIP conjugates induced cytotoxic cell destruction indicating the utility of GIP segments as cancer therapeutic agents. Following a discussion of the preceding results, a candidate cell surface receptor family was proposed which correlated with previous published reports for a putative AFP/GIP receptor.

[Antiaggregant properties of new 1,3,4-thiadiazine derivatives].

A series of new 1,3,4-thiadiazine derivatives have been synthesized and their effect on the human platelet aggregation in vitro has been studied. All the tested substances inhibit the human platelet aggregation induced by ADP and arachidonic acid in a broad concentration range. The most active 1,3,4-thiadiazines (L-19, L-28 and L-31) effectively inhibit platelet aggregation at concentrations within 0.01-1 mM.

Anticoagulant activity of original synthetic peptide derivatives.

Original synthetic peptide derivatives exhibit anticoagulant activity in vitro and in vivo. They delayed fibrin clot formation from human blood plasma in tests for the intrinsic coagulation pathway (activated partial thromboplastin time) and final stage of plasma coagulation (thrombin time) and inhibited amidolytic activity of thrombin. We determined the minimum effective dose of the most active compound providing a 2-fold lengthening of blood clotting time (activated partial thromboplastin time test and thrombin time test), which persisted for 2-3 h.

Localization of Mullerian inhibiting substance receptors in various human cancer cell lines.

Recombinant human MIS (rhMIS) produced in transfected Chinese hamster ovary cells has been purified by immunoaffinity chromatography. In the absence of reducing agents, 140 kD homodimer and several oligomers with molecular masses from 280 to 1000 kD are present. Homodimer, tetramer, and higher-molecular-weight rhMIS fractions reduced survival of tumor cells. For these experiments, FITC-labeled rhMIS was used for binding and endocytosis studies by flow cytometry. Flow cytometry performed on MIS-sensitive cancer cell lines demonstrated specific binding of rhMIS. The majority of rhMIS receptors have cytosolic localization. Thus, the level of MIS receptors on the cell membrane was proportional to the content of MIS-binding proteins in the whole cell and defines a level of receptor-mediated endocytosis. The immunopurified rhMIS caused significant growth inhibition of ovarian and prostate adenocarcinoma and melanoma human cell lines in inhibition assays.

Inhibition of thrombin and factor Xa by Fucus evanescens fucoidan and its modified analogs.

Specimens of fucoidan extracted from Fucus evanescens were purified from protein and polyphenols, deacetylated and depolymerized by fucoidanase for evaluation of their biological activity. Deacetylation did not modify the capacity of fucoidan to inhibit thrombin and factor Xa, while purification from protein and polyphenols reduced this capacity. Depolymerization of fucoidan increased its capacity to inhibit thrombin mainly through heparin cofactor II. All the studied specimens formed complexes with protamine sulfate.

[Effect of RGD-containing peptides on platelet aggregation].

The influence of new synthetic peptides ARGDS-NH2 and RGD-dFK (synthesized by the fermentative method) and VPNLRGDLQVLA (a fragment of the foot-and-mouth virus's surface peptide) on the ADP-induced human platelet aggregation in vitro was studied. All peptides were found to inhibit the human platelet aggregation, but the synthetic peptides (ARGDS-NH2 and RGD-dFK) showed the most pronounced effect. Significant decrease in the platelet aggregation was observed at their concentrations within 0.1-10 mM. ARGDS-NH2 and RGD-dFK inhibited the platelet aggregation stronger than the reference drug pentoxifylline at equivalent concentrations.

[Effect of the new antimigraine drug serotonin receptor antagonist tropoxin on platelet aggregation].

The effect of the new antimigraine drug tropoxin - the serotonin receptor (5-HT2) antagonist - on the human platelet aggregation in vitro induced by ADP (1 x 10(-5) M) and epinephrine (2.5 x 10(-6) M) was studied. Tropoxin reliably inhibited the ADP-induced platelet aggregation in a concentration range of 0.01 - 7 mg/ml. A significant inhibition effect with respect to the epinephrine-induced platelet aggregation was observed in a drug concentration range of 2 - 7 mg/ml, although a reliable antiaggregant activity was also observed below 2 mg/ml. A bolus administration of tropoxin (10 mg/kg) in rabbits decreased the ADP-induced platelet aggregation ex vivo by a factor of 1.2 - 1.4. The effect appeared 45 min after treatment and was observed during subsequent 30 min.

[A new method for determination of antithrombin III and its diagnostic significance]. / Novyi metod opredeleniia antitrombina III i ego diagnosticheskoe znachenie.

A new assay based on using an original chromogenic substrate (z-Ala-Ala-Arg-pNa) and designed for the determination of antithrombin III is described in the paper. It was used in examinations of patients with malignancy after surgery. The content of antithrombin III was detected to be lower in 12% of cases in 2 days after surgery. Additionally, patients with DIC, as complications after surgery, were examined to find out that the antithrombin III content was decreasing in them.

[Synthesis of modified peptides with C-terminal alpha-amino aldehydes]. / Sintez modifitsirovannykh peptidov, soderzhashchikh na C-kontse alpha-aminoal'degidy.

Various synthetic approaches to modified peptides with the C-terminal aldehyde group, capable of inhibiting a number of proteolytic enzymes belonging to the classes of thiol, serine, and aspartyl proteases, are considered. Both chemical methods, including solid phase peptide synthesis now widely used, and biocatalytic synthetic methods for obtaining these substances are discussed in detail.

[Design of the human tumor-associated VNTR(Muc1) antigen gene, fused with streptavidin, its expression in Escherichia coli. Study of properties of the hybrid protein]. / Konstruirovanie gena opukholeassotsiirovannogo antigena VNTR(Muc1) cheloveka, slitogo so streptavidinom, ego ékspressiia v Escherichia coli. Izuchenie svoistv gibridnogo belka.

A gene of human tumor-associated antigen VNTR(MUC1) bound to streptavidin, an expression plasmid, and a highly effective hybrid protein-producing strain were constructed. It was shown that the streptavidin leader peptide ensures an effective secretion of the hybrid protein into the periplasmic space of Escherichia coli cells. The hybrid protein was isolated in a homogeneous state and its immunogenic properties were studied.

[The effect of the joint administration of heparin and chitosan sulfate ether on hemostatic function]. / Vliianie sovmestnogo vvedeniia geparina i sernokislogo éfira khitozana na funktsiiu gemostaza.

We studied anticoagulant effects of combined administration of heparin (H) and chitosan sulfate ether (CS) (specific activity 20 UE/mg) in the ratio 1 : 1. CS enhanced anticoagulant activity of heparin in rabbits by a factor of 1.95 +/- 0.15. The intravenous injection of the mixture in a dose of 0.5 mg(H)/kg + 0.5 mg(CS)/kg and heparin injection in a dose of 1mg/kg induced the same effect. Haemorrhagic effect of this mixture was less pronounced compared to heparin, anticoagulant and antithrombotic activities remained the same. The mixture was found to decrease a number of platelets, however, this was also less pronounced compared to heparin. Thus, the use of the mixture CS + H (1 : 1) instead of double heparin dose resulted in the same effect.

[The effect of fluorinated prostaglandins on platelet aggregation]. / Vliianie ftorirovannykh prostaglandinov na agregatsiiu trombotsitov.

The effects of fluorodeoxy prostanoids on platelet aggregability were studied. It was shown that introduction of fluorine into positions 9, 11 or 15 of prostaglandin F2 alpha led to enhanced proaggregation activity. The most active compound among fluorodeoxy analogs was 15-fluoro derivative; bisfluoro analog was moderately active, and 11-fluoro compound had the least activity. In the group of fluorodeoxy prostaglandins E2, a contrary effect was registered. Thus, the most active compound was 1-fluoride and the least, 15-fluoride. The incorporation of fluorine into position 15 of prostacyclin led to insignificantly lower antiaggregatory activity just as this modification of 6-keto-prostaglandin F1 alpha was accompanied by a dramatic increase in its ability to inhibit platelet aggregation.

Protein C activator from the venom of Agkistrodon blomhoffi ussuriensis retards thrombus formation in the arterio-venous shunt in rats.

Protein C (PC) is an anticoagulant protein which, being activated by thrombin, degrades factors V/Va and VIII/VIIIa and releases a tissue-type plasminogen activator. Some Agkistrodon snake venoms contain PC activators which, in experiments, exert an anticoagulant action. An antithrombotic effect of the PC activator from the venom of A. blomhoffi ussuriensis on the model of thrombus formation in the arterio-venous shunt in rats was under investigation. Administration of the PC activator resulted in a dose-dependent prolongation of the thrombus formation time and a decrease in plasma PC activity, which were accompanied by a decrease in factor V activity and APTT prolongation. No reliable changes in the t-PA level, ADP- and epinephrine-induced platelet aggregation were observed. Platelet adhesion to glass beads diminished. We assume that the antithrombotic effect of the PC activator from the A. blomhoffi venom in the platelet-dependent thrombosis model is caused by PC activation and subsequent factor V inactivation as well as by platelet adhesiveness reduction.