Melatonin Prevents Early but Not Delayed Ventricular Fibrillation in the Experimental Porcine Model of Acute Ischemia

Antiarrhythmic effects of melatonin have been demonstrated ex vivo and in rodent models, but its action in a clinically relevant large mammalian model remains largely unknown. Objectives of the present study were to evaluate electrophysiological and antiarrhythmic effects of melatonin in a porcine model of acute myocardial infarction. Myocardial ischemia was induced by 40-min coronary occlusion in 25 anesthetized pigs. After ischemia onset, 12 animals received melatonin (4 mg/kg). 48 intramyocardial electrograms were recorded from left ventricular wall and interventricular septum (IVS). In each lead, activation time (AT) and repolarization time (RT) were determined. During ischemia, ATs and dispersion of repolarization (DOR = RTmax − RTmin) increased reaching maximal values by 3–5 and 20–25 min, respectively. Ventricular fibrillation (VF) incidence demonstrated no relations to redox state markers and was associated with increased DOR and delayed ATs (specifically, in an IVS base, an area adjacent to the ischemic zone) (p = 0.031). Melatonin prevented AT increase in the IVS base, (p < 0.001) precluding development of early VF (1–5 min, p = 0.016). VF occurrence in the delayed phase (17–40 min) where DOR was maximal was not modified by melatonin. Thus, melatonin-related enhancement of activation prevented development of early VF in the myocardial infarction model.     

Geochemistry of the Detroit River Sediments

The objectives of the investigation were to provide information on the concentration and distribution of metals in bottom sediments of the Detroit River and to study the association of metals with various sediment components. Concentrations of major elements (Si, Al, Ca, Mg, Na, K, Fe, Mn, and P) and metals (Co, Cr, Cu, Ni, Pb, and Zn), particle size distribution, and mineralogical composition were determined in 20 surficial sediment samples collected along the Detroit River in 1983. Significantly higher concentrations of metals in the Detroit River sediments than those reported in Lake St. Clair and Lake Erie sediments indicated input from sources in the river's drainage basin. Poor relationships exist between the metals and organic C and the metals and the silt-clay size fraction (< 63 μm). The association of metals with sediment particles was investigated by a separation of sediment into seven size fractions ranging from < 13 to > 63 μm. Zn, Ni, Cr, and Pb were accumulated in the < 13 μm size fraction. However, Cu and Cr concentrations were highest in the < 13 and 48 to 63 μm fractions. Quartz, feldspars, and calcite were found in the > 63 μm fraction. Dolomite, feldspars, and quartz were in the 13 to 63 μm fraction and the clay minerals illite, chlorite, and kaolinite were in the < 13 μm fraction. Concentrations and relationships among major elements reflected the mineralogical composition of different particle size fractions.     

In search of a “Non-citation index” indicator for scientific activity assessment in less developed countries. Case study of Croatia/Yugoslavia

The meaning of the term the intellectual island effect which was introduced byArunachalam et al. is broadened as to characterize the status of science on the periphery in general. A practical solution is proposed, based on bibliometric data of the research output and relying on two criteria: the extent of coverage by world significant secondary literature and the extent of scatter of that literature. Reliability of the publication data retrieved from the Citation Indexes is discussed; a measure is offered to assess the adequacy of the Citation Indexes as the data sources.Unquestionably, there has been no one like Einstein in physics in this century, but one has to reflect on how easily Einstein might have been lost, particularly if he had been born in a developing country.From C. M. KINNON, (Ed.)The Impact of Modern Scientific Ideas on Society Reidel/UNESCO, 1981, p. 29.     

Breite Einwilligung (<Emphasis Type="Italic">broad consent</Emphasis>) zur Biobank-Forschung – die ethische Debatte

Definition of the problem

Ethical aspects of biobanking research are receiving increasing attention in the literature. It is particularly controversial which model of consent should be implemented in research biobanks.

Arguments

This paper outlines the ethical controversy surrounding various models of consent into biobank-based research. Following a brief introduction of established consent models, it delineates the development of alternative approaches and discusses the ethical and regulatory challenges associated with these. Relevant ethical principles are highlighted.

Conclusion

The article concludes that there are good reasons to trial a combination of initial broad consent with consent to governance for future biobanking research in Germany.

     

Particle coagulation at semicontinuous emulsion polymerization. II. Characterization of surface groups

Semicontinuous emulsion polymerization of acrylic monomers with a monomer emulsion feed has been investigated. The amount of coagulum appearing during the polymerization under conditions of insufficient covering of particle surface by emulsifier was studied from the point of view of particle surface charge. Increasing the surface group concentration via copolymerization of butyl acrylate with acrylic acid or sulfoethyl methacrylate caused increased colloid stability of the system and a rapid decrease in coagulum formation. It was established that during the polymerization acid hydrolysis of ester groups took place, which caused an increase in the carboxyl groups concentration at the particle surface. These carboxyl groups contribute to the colloid stability of the polymerizing system.     

Poly(2-oxazoline) hydrogels by photoinduced thiol-ene “click” reaction using different dithiol crosslinkers

Fabrication of a library of biocompatible hydrogels by photoinduced thiol-ene “click” reaction is described. The hydrogels are based on two different statistical copolymers consisting of 2-butenyl-2-oxazoline (EnOx) with either 2-methyl-2-oxazoline (MeOx) or 2-ethyl-2-oxazoline (EtOx). Crosslinking is achieved via pendant vinyl groups of EnOx in the copolymers with selected dithiol crosslinkers, namely dithiothreitol, 1,3-propanedithiol, 1,6-hexanedithiol, and 1,9-nonanedithiol by thiol-ene photocoupling. On the basis of different polarity and flexibility of particular dithiols and three different molar ratios to double bonds, it is possible to control swelling and mechanical characteristics of resulting hydrogels. Biocompatibility of all hydrogel types is verified by determination of toxicity of hydrogel extracts and contact direct toxicity towards mice 3T3 fibroblast cell line. The resulting low toxicity of all prepared hydrogels predetermines its utilization in biomedicine.     

Historiography of Czech psychology.

The paper is aimed at presenting the development of the Czech historiography of psychology, which was strongly influenced by the political changes in Central and Eastern Europe. The authors deal with the historiography of psychology at the three universities offering an undergraduate program in psychology, located in Prague, Brno, and Olomouc, and at the Institute of Psychology of the Czech Academy of Sciences. Recent research, teaching, textbooks, and journal articles published in Czech and in foreign languages are showcased. The historiography of Czech psychotherapy is mentioned as a special thematic development. Contemporary problems and perspectives in the field of the history of psychology in the Czech Republic are discussed, sources of information are given. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Number and size of lupulin glands,glandular trichomes of hop (Humulus lupulus L.), play a key role in contents of bitter acids and polyphenols in hop cone

Hop (Humulus lupulus L.) inflorescence, commonly known as ‘hop cone’, is valuable for contents of bitter acids, essential oils and polyphenols, used in brewing industry and biomedical application. These compounds are predominantly formed in glandular trichomes, known as ‘lupulin glands’. In this study, we investigated chemical and morphological characteristics of lupulin glands by microscopy and HPLC analyses. Even though no significant correlations were found between lupulin glands and hop cones for contents of alpha and beta bitter acids, polyphenols, all ratios between individual metabolites (alpha/beta acids, X/alpha acids, X/DMX) were highly and significantly correlated. The average number of lupulin glands on bract/bracteole ranged from 115 to 713 with 28.5% of variability. Linear regression analyses confirmed that total volume of lupulin glands and total lupulin glands area on bract/bracteole surface highly correlated with contents of bitter acids and polyphenols in hop cone. Therefore, lupulin glands are unique and exclusive organs responsible for contents of bitter acids and polyphenols in hop cone.     

Safety effects of section control - An empirical Bayes evaluation

The safety effects of section control were investigated at 14 sites in Norway. A before–after study was conducted with the empirical Bayes method in order to control for regression to the mean (RTM). Effects of trend, volumes, speed limit changes and speed cameras at some of the sites in the before period are controlled for as well. For injury crashes a non-significant reduction by 12% was found. The number of killed or severely injured was found to be significantly reduced by 49% at the section control sites. The results indicate that the crash reductions in tunnels (most of which are undersea tunnels with section control on steep downhill segments) are at least of the same magnitude as on open roads. The results are consistent with findings from speed measurements, although the crash reductions are larger than one would expect as a result from the speed reductions. Downstream of the section control sites (up to 3 km in each direction) injury crashes were found to be significantly reduced by 46%. The number of KSI downstream of the section control sites is too small for drawing any conclusions. It is concluded that section control is effective in reducing both speed and crashes, especially serious crashes, and that spillover effects (crash reductions at non-enforcement sites) are more likely to occur than crash migration. The size of the effects that were found should be interpreted with caution because of the relatively short after periods for some of the sites and the sensitivity of the results to the outcomes of individual crashes.     

Können, sollen, müssen? Public Health-Politik und libertärer Paternalismus

Definition of the problem Due to the epidemiological transition that has occurred over the last few decades, diseases caused by behaviour have become one of the most important challenges for modern public health practice and policy. However, assigning responsibility for health and modifying behaviour are fraught with ethical problems. As of now, there is still the need for a theoretical model which manages to solve these issues successfully. Arguments Recently, libertarian paternalism has been heralded as a theoretical model which can inform policy making in public health and other areas of social policy. This article describes the account and discusses some of its problematic features. Conclusions To satisfy requirements of a fully argued normative account, libertarian paternalism lacks central elements of justification. However, it serves very well as a pragmatic tool providing original ideas for designing acceptable public health policy.