Detection of human neuronal α7 nicotinic acetylcholine receptors by conjugates of snake α-neurotoxin with quantum dots.

Fluorescent derivatives are widely used to study the structure and functions of proteins. Quantum dots (QDs), fluorescent semiconductor nanocrystals, have a high quantum yield and are much more resistant to bleaching compared to organic dyes. Conjugates of α-neurotoxins with QDs were used for visualization of human α7 acetylcholine receptors heterologously expressed in GH4C1 pituitary adenoma cells. Specific staining of cells by the conjugated toxins was observed.

Exploiting Le Chatelier's principle for a one-pot synthesis of nontoxic HHogGNPs with the sharpest nanoscopic features suitable for tunable plasmon spectroscopy and high throughput SERS sensing.

Applying Le Chatelier's principle, a one-pot synthesis method is reported that generates highly anisotropic hedgehog gold nanoparticles (HHogGNPs), undemanding of a preformed seed or surfactant. These non-toxic HHogGNPs are potent candidates for nanomedicinal applications owing to their broad-band plasmon tunability, gigantic Raman enhancement and remarkable retention in a highly salted physiological environment.

[Factors Associated With Development of Atrial Fibrillation After Coronary Artery Bypass Grafting].

PURPOSE: to identify factors associated with development of atrial fibrillation (AF) in the early postoperative period of coronary artery bypass grafting (CABG). METHODS: A total of 376 patients with ischemic heart disease who underwent CABG were enrolled in the study. RESULTS: During the observation period AF occurred in 74 patients (19.7%, 93% men, mean age 64.0+/-6.4 years), an average of 3.6+/-2 days after surgery. Multivariate regression analysis showed that odds ratio (OR) for AF in patients with age >59 years was 1.5 (95% confidence interval [CI], 1.1-3.5; p=0.04), aortic cross-clamping time >43 min - 2.4 (95% CI, 1.05-6.2; p=0.03), left atrial dimension (LAD) >39 mm - 5.0 (95% CI, 2.0-12.6; p=0.0006), left ventricular ejection fraction (LVEF) <51% - 3.6 (95% CI, 1.6-8.3, p=0.002). During ROC - analysis the high sensitivity was observed for LAD >39 mm (82%, =0.001), high specificity - for LVEF <51% (80%, =0.0009), highest positive likelihood ratio for LVEF <51% - 2.56 (=0.0009), greatest negative likelihood ratio for LAD >39 mm - 0.31 (=0.001). CONCLUSION: In our study, the risk of AF development in the early postoperative period of CABG depended on the patients age, left atrial size, left ventricular ejection fraction, and aortic cross-clamping time during CABG.

Nonconventional three-finger toxin BMLCL from krait Bungarus multicinctus venom with high affinity interacts with nicotinic acetylcholine receptors.

Nonconventional three-finger toxin BMLCL was isolated from B. multicinctus venom, and its interaction with different subtypes of nicotinic acetylcholine receptor (nAChR) was studied. It was found that BMLCL is able to interact with high efficiency with both α7 and muscle type nAChRs.

[Ischemic heart disease complicated by heart failure: possibilities of surgical treatment].

Aim of the study was to assess remote results of surgical reconstruction of the left ventricle (LV) in patients with ischemic heart disease (IHD) and chronic heart failure (CHF). During 1996-2010 136 patients with IHD complicated by CHD were subjected to surgery. The patients were divided into 2 groups: with LV aneurism (group 1, n=70) and with ischemic cardiomyopathy (group 2, n=66). In all patients we performed coronary bypass surgery and Dor LV reconstruction. Moderate and high degree mitral regurgitation was corrected. Hospital mortality was 5.4% in group 2. There were no inhospital deaths in group 1. In all survivors we noted reduction of LV dimensions and sphericity of LV cavity, increase of LV ejection fraction. Ten year survival was 78 and 56,5% in groups 1 and 2, respectively. In 10 years after surgery 80.2 and 68% of patients, respectively, had no signs of high NYHA class (III-IV) CHF. Thus surgical intervention on all components of intracardiac pathology in patients with IHD with CHF allowed to achieve satisfactory long term results.

Cell proliferation in normal and malignant transformed cells: thermodynamic model of signal transduction.

We present a new thermodynamic model for the mechanism of activation and regulation of cell proliferation in the G1 stage. In this model, the interactions between growth factors and transmembrane proteins play a crucial role in cell growth control for a normal tissue-culture system. We calculate a phase diagram of normal and malignant transformed states of a cell signal transduction system. We propose thermodynamic reasons why cancer cells can continually grow without activation by the growth factors.

[A comparison of the analgesic effect of ketanov and tramal in postoperative pain]. / Sravnenie analgeticheskogo éffekta ketanova i tramala pri posleoperatsionnykh boliakh.

The efficacy of postoperative pain relief by ketanov and tramal was assessed in 42 patients operated on the abdominal organs and lower limb arteries. The time of development of the analgesic effect and duration and depth of analgesia were compared. The drug effects were compared from protocols of clinical examination, hemodynamic changes, and time course of external respiration and blood saturation with oxygen. The findings confirm a high analgesic effect of ketanov, which is not inferior to tramal, and by some parameters even higher.

[Ionic pairs in Bacillus intermedius 7P ribonuclease]. / Ionnye pary v strukture ribonukleazy Bacillus intermedius 7P.

On the basis of X-ray determined coordinates specified with computer graphics and new data on amino acids sequence in the structure of Bacillus intermedius 7P ribonuclease there were analysed potentially charged residues and found ionic pairs binding independently denaturing regions-energetic domains. Five clusters of charged amino acids were found in the protein structure and several ionic bonds between the energetic domains were discovered: Asp7, Asp11-Arg109 and Lys26-Asp53,Glu72. Breaking of the latter makes their heat denaturation independent. Local surrounding of the ionic bonds is characterized and their role in the structure and cooperative properties of the globule is discussed.

[A theoretical model of DNA packaging in the phage head]. / Teoreticheskaia model' upakovki DNK v golovke faga.

Statistical model of dsDNA packaging to icosahedral bacteriophage capsid is presented. The model describes intraphage DNA as a globule, i.e. intramolecular liquid crystal. We analyse the free energy of DNA, which has a globulized part inside the phage capsid and coil-like tail outside it. Conditions when processes of DNA movement into capsid or back are thermodynamically favorable are investigated. These processes are not accompanied with any thermal effects. It is not "all or none" type process, i.e. intermediate stable states are possible. The role of DNA interaction with the capsid inner wall is considered. The essential model abilities for qualitative explanation of experimental data are exhibited.

[Structural transformations of fibrin oligomers]. / Strukturnye prevrashcheniia oligomerov fibrina.

The morphology of equilibrium of soluble fibrin oligomers at different stages of assembly was studied. Results of Rauleigh's light scattering, analytical ultracentrifugation and viscosimetry show that fibrin-polymers throughout the entire homology range present rigid, rod-like structures dispersed by weight and dimensions. It was shown, that along with the traditional double-stranded chain protofibrills, where the monomer molecules are connected "end-to-center", there is an alternative variant, which is a result of single-stranded chain dimerization, where the monomers are formed up in an "end-to-end" fashion. Identity of physicochemical features of fibrin oligomers obtained by means of different enzyme activation of fibrinogen indicates that E1 and E2 sites interact with the complementary D1 and D2 sites only at the stage of protofibrill formation. It is suggested that the lateral aggregation is initiated by other sites that exist in fibrinogen and fibrin-monomer molecules in an accessible state. Thermodynamic reasons for the cooperative ability of protofibrill aggregation processes and gel-formation are discussed.

[Mechanism of self-assembly of soluble fibrin oligomers and the role of fibrinopeptides A and B in this process]. / Mekhanizm samosborki rastvorimykh oligomerov fibrina i rol' fibrinopetidov A i B v étom protsesse.

Three-dimensional organization of intermediate soluble forms of fibrin-polymers--a product of fibrin-monomer assembly--in the presence of non-denaturating urea concentrations has been studied. Hydrodynamic parameters of fibrinogen and fibrin-polymers were obtained by viscosimetry, dynamic light scattering and analytic ultracentrifugation. Using Yamakawa's hydrodynamic theory and considering fibrinogen molecule as an oblate ellipsoid of revolution made it possible to estimate the concentration effect on the coefficient of translational friction in the first, according to concentration, linear approximation. Hydrodynamic constants against polymer molecular weights were plotted using Swedberg's and Kuhn--Mark's equation. This made it possible to prove the existence of equilibrium single-stranded protofibrils formed by fibrin-monomer "end-to-end" association. It was concluded that local conformational transformations in fibrin-monomer molecule result in diminishing the complementarity of lateral binding sites; less specific D--D contacts remaining the only means of the "end-to-end" association. Experimentally obtained data give evidence that polymerization region is shifted towards much lower urea concentration, fibrinopeptide B being preserved. Therefore, the possibility of several conformational states of protein molecules during fibrinogen--fibrin transformation is discussed. It is supposed that changes in structure concern not only the central E-, but also the peripheral D- or alpha C-domains.