Synthesis and cardioprotective properties of apelin-12 and its structural analogues

Apelin-12 and a number of its analogues (Nle¹⁰-, MeArg¹, Nle¹⁰, MeArg¹, Nle¹⁰, Phe¹²-NH₂-, Arg¹(NO₂), Nle¹⁰, Phe¹²-NH₂-), resistant to the degradation of proteases, were synthesized by the Fmocmethod of SPPS. By-products of synthesis were examined. It was found that the serine hydroxyl group was sulfating during the final deprotection of apelin-12 and its analogues. The sulfate moiety of the Arg-protecting group transfers into the hydroxyl group of Ser. The amount of by-product depends on the water presence in cleavage mixture. Furthermore, the final deprotection of amide analogues of apelin-12 was accompanied by the formation of a by-product — 4-hydroxybenzylamide; its amount ranged from 20% to 8% in the reaction mixture (according to HPLC data) and also depended on the composition of the cleavage mixture. Effects of the synthesized peptides on recovery of the cardiac function after ischemia were examined in a model of isolated perfused rat heart. Infusions of any of the peptides (I–V) before ischemia resulted in a significant improvement of contractile and pump function recovery compared with the control. Cardioprotective efficacy of the peptides increased in the following rank (I) < (II) = (III) < (IV) = (V).     

Peptide Fragments and Structural Analogues of Chemokine MCP-1: Synthesis and Effect on the MCP-1-Induced Migration of Mononuclear Cells

Fourteen fragments and structural analogues of chemokine MCP-1 were synthesized using the Fmoc-strategy of solid phase peptide synthesis. The effect of synthesized peptides on the MCP-1-stimulated migration of mononuclear cells was examined. Both in vitro stimulants and inhibitors of the monocyte migration were found among the peptides. A possible participation of the C-terminal part of the MCP-1 molecule in the inhibition of the MCP-1-stimulated cell migration was found for the first time.     

A Percolation Lattice of Natural Selection as a Switch of Deterministic and Random Processes in the Mutation Flow

Biophysics - This review considers the basic models of mutation processes that occur during selection and drift. A basically new model was developed to describe the mutation flow through a...     

Glial cell line-derived neurotrophic factor family ligands and their therapeutic potential

Four glial cell line-derived neurotrophic factor (GDNF) family ligands (GFLs) have been characterized: GDNF, neurturin (NRTN), artemin (ARTN) and persephin (PSPN). These proteins support and restore multiple neuronal populations such as dopaminergic, sensory, motor, hippocampal, basal forebrain, enteric, sympathetic and parasympathetic neurons. Therefore, GFLs attracted significant attention as a potential cure for the diseases caused by neuronal injury and degeneration. Results of multiple experiments indicate that GFLs can alleviate behavioral symptoms and restore affected neurons in animal models of several neurological disorders including, among others, Parkinson’s disease (PD). During the last decade, GDNF protein and NRTN gene therapy have been tested in several clinical trials in patients with PD. Although the results of phase I clinical trials were positive, phase II clinical trials failed to reach primary end-points. Poor pharmacokinetic properties of GFLs (inability to penetrate tissues barriers, high affinity for extracellular matrix, etc.) could contribute to the absence of clear clinical benefits of these proteins for the patients. The purpose of this paper was to review therapeutic potential of GFLs and discuss possibilities to overcome difficulties associated with pharmacokinetic properties and delivery of GFLs to target neurons.     

From recommendation to action: psychosocial factors influencing physician intention to use Health Technology Assessment (HTA) recommendations

Background

The Evidence-Based Practice (EBP) Project has been investigating the implementation of evidence-based mental health practices (Assertive Community Treatment, Family Psychoeducation, Integrated Dual Diagnosis Treatment, Illness Management and Recovery, and Supported Employment) in state public mental health systems in the United States since 2001. To date, Project findings have yielded valuable insights into implementation strategy characteristics and effectiveness. This paper reports results of an effort to identify and classify state-level implementation activities and strategies employed across the eight states participating in the Project.

Methods

Content analysis and Greenhalgh et al's (2004) definition of innovation were used to identify and classify state-level activities employed during three phases of EBP implementation: Pre-Implementation, Initial Implementation and Sustainability Planning. Activities were coded from site visit reports created from documents and notes from key informant interviews conducted during two periods, Fall 2002 – Spring 2003, and Spring 2004. Frequency counts and rank-order analyses were used to examine patterns of implementation activities and strategies employed across the three phases of implementation.

Results

One hundred and six discreet implementation activities and strategies were identified as innovative and were classified into five categories: 1) state infrastructure building and commitment, 2) stakeholder relationship building and communications, 3) financing, 4) continuous quality management, and 5) service delivery practices and training. Implementation activities from different categories were employed at different phases of implementation.

Conclusion

Insights into effective strategies for implementing EBPs in mental health and other health sectors require qualitative and quantitative research that seeks to: a) empirically test the effects of tools and methods used to implement EBPs, and b) establish a stronger evidence-base from which to plan, implement and sustain such efforts. This paper offers a classification scheme and list of innovative implementation activities and strategies. The classification scheme offers potential value for future studies that seek to assess the effects of various implementation processes, and helps establish widely accepted standards and criteria that can be used to assess the value of innovative activities and strategies.     

The effect of pyruvate on antibody interaction with group-specific erythrocyte antigens

Using the AB0 antibody-antigen model the influence of natural metabolite pyruvate on the antibody interaction with of erythrocyte antigens, defining their group specificity has been investigated. Before agglutination reaction erythrocytes of A (II)–AB (IV) blood groups, monoclonal anti-A and anti-B antibodies were incubated with sodium pyruvate. Visualization of agglutinates was performed by means of flow cytometry and laser scanning confocal microscopy. Computer-aided prediction of the spectrum of biological activity of pyruvate by a PASS program proposed major regulatory pathways, in which pyruvate may be involved. It has been demonstrated that pyruvate can regulate the intensity of antigen-antibody interaction. These results suggest the possibility of using small molecules, for example pyruvate, as molecular probes and prospects of the use of erythrocytes with antigenic determinants of the ABO system expressed on their membranes for studies of protein-protein interactions due to convenient visualization and possibility of quantitative evaluation of this process.     

The possible mechanisms of the adaptation of microbial populations to low positive temperatures

Biologically low temperature was studied for its effect on the survival of populations and their biochemical and molecular-genetical state. The research was carried out on Yersinia pseudotuberculosis and Shigella sonnei models. It is established that the process of low-temperature adaptation of the populations may occur either at the level of the whole population with participation of inducible cold isoenzymes or at the level of a part of population, the temperature being a selection factor of the adapted cells.