Leptin-induced endothelium-dependent vasorelaxation of peripheral arteries in lean and obese rats: role of nitric oxide and hydrogen sulfide.

Published onlineJournal ArticleResearch Support, Non-U.S. Gov'tAdipose tissue hormone leptin induces endothelium-dependent vasorelaxation mediated by nitric oxide (NO) and endothelium-derived hyperpolarizing factors (EDHF). Previously it has been demonstrated that in short-term obesity the NO-dependent and the EDHF-dependent components of vascular effect of leptin are impaired and up-regulated, respectively. Herein we examined the mechanism of the EDHF-dependent vasodilatory effect of leptin and tested the hypothesis that alterations of acute vascular effects of leptin in obesity are accounted for by chronic hyperleptinemia. The study was performed in 5 groups of rats: (1) control, (2) treated with exogenous leptin for 1 week to induce hyperleptinemia, (3) obese, fed highly-palatable diet for 4 weeks, (4) obese treated with pegylated superactive rat leptin receptor antagonist (PEG-SRLA) for 1 week, (5) fed standard chow and treated with PEG-SRLA. Acute effect of leptin on isometric tension of mesenteric artery segments was measured ex vivo. Leptin relaxed phenylephrine-preconstricted vascular segments in NO- and EDHF-dependent manner. The NO-dependent component was impaired and the EDHF-dependent component was increased in the leptin-treated and obese groups and in the latter group both these effects were abolished by PEG-SRLA. The EDHF-dependent vasodilatory effect of leptin was blocked by either the inhibitor of cystathionine γ-lyase, propargylglycine, or a hydrogen sulfide (H2S) scavenger, bismuth (III) subsalicylate. The results indicate that NO deficiency is compensated by the up-regulation of EDHF in obese rats and both effects are accounted for by chronic hyperleptinemia. The EDHF-dependent component of leptin-induced vasorelaxation is mediated, at least partially, by H2S.The study was supported by the EU Project “The equipment of innovative laboratories doing research on new medicines used in the therapy of civilization and neoplastic diseases” within the Operational Program Development of Eastern Poland 2007 - 2013, Priority Axis I Modern Economy, Operations I.3 Innovation Promotion. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Ecophysiology and dynamics of nitrogen removal bacteria in a sequencing batch reactor during wastewater treatment start‑up

Nitrogen removal communities performing wastewater treatment consist of ammonia oxidisers, nitrite oxidisers, denitrifiers, and anammox bacteria, and the proportion and activity of particular microbial groups depend not only on the physiochemical parameters of the bioreactor, but also on the composition of the inoculum. Nitrifiers and denitrifiers usually dominate in conventional wastewater treatment systems due to the fact that nitrification and denitrification are the most commonly used nitrogen removal processes. However, from the economical point of view in case of wastewater with high ammonia concentrations, anammox-based technologies are desirable for their treatment. The disadvantage of such systems is slow anammox bacteria growth, which extends an effective technological start-up. Thus, in this study, a fast start-up of the anammox process supported with an anammox-rich inoculum was performed in a sequencing batch reactor (SBR). Using anammox inoculation of SBR laboratory system, the start-up can be fastened to 85 days with 84.5% of nitrogen removal efficacy. The spatial distribution of nitrogen removal bacteria analysed with fluorescent in situ hybridisation revealed that anammox and nitrifiers are located side by side in the flocs and the relative number of ammonia and nitrite oxidisers decreased after 85 days of the experiment

Biomaterials recycling: a promising pathway to sustainability

Biomaterials undergo a transformative journey, from their origin as renewable resources to the manufacturing plants where they are processed and stored, until they fulfill their intended therapeutic or diagnostic purposes and become medical waste. However, during this life cycle, biomaterials can be susceptible to contamination and subsequent degradation through various mechanisms such as hydro-mechanical, thermal, or biochemical processes in water, soil, or air. These factors raise significant concerns regarding biological safety. Additional complexities arise from the potential amalgamation of biomaterials with other materials, either of the same kind or different types. Use of biomaterials influences their porosity, surface chemistry, and structural strength, and these factors affect biomaterials’ reusability. Given the multitude of materials, processing parameters, sustainability requirements, and the limitation of natural resources, the recycling of biomaterials becomes necessary. Unfortunately, this topic has received limited attention thus far. In this context, this perspective provides a brief overview, analysis, and classification of reports on biomaterials recycling, aiming to initiate a discussion on this frequently overlooked subject. We highlight the challenges related to energy consumption and environmental pollution. However, the lack of established protocols and reporting on biomaterials recycling prevents a comprehensive understanding of these challenges and potential solutions. Nevertheless, addressing these issues can lead to more efficient resource use and reduced environmental impact in the field of biomaterials

The use of spa and phage typing for characterization of clinical isolates of methicillin-resistant Staphylococcus aureus in the University Clinical Center in Gdańsk, Poland

The emergence of spa types and spa–clonal complexes (CC) among clinical methicillin-resistant Staphylococcus aureus isolates collected from the University Clinical Center in Gdańsk between 2008 and 2009 were investigated. Phage typing was used as the initial screening in the study. The basic set of phages and the additional set of phages were used. Most of the isolates (56 %) belonged to the phage group III. With the additional set of phages, eight types were found, with predominant one MR8 (50 %). Sixteen distinct spa types were observed. The most frequent were t003 (22 %), t151 (16 %), and t008 (12 %). The spa types were clustered into two spa-CC and eight singletons. The predominant CC010 (50 %) consisted of six types, with the most common t003 (36.7 %) and t151(26.7 %), and in 80 % was identified as staphylococcal chromosomal casette mec (SCCmec) type II. The second cluster has no founder (12 %) with only two spa types: t037 belonging to SCCmec type III and t029. In the most frequent singleton, spa type t008 alone was clustered in 12 % of the isolates. All singletons correspond to SCCmec type IV. The CC010 was distributed in most of the hospital wards, corresponded to Multilocus sequence typing type ST5/ST225 and was constantly present throughout the observed period. The isolates of CC010 generally belonged to the phage group III, and most of them (53.3 %) were resistant to erythromycin, clindamycin, and ciprofloxacin. The concordance between spa-clone and phage type was very high, but the same phage type MR8 was observed within different spa types of the predominant clone

Development of High Technologies as an Indicator of Modern Industry in the Eu

The article tries to classify the EU states in terms of the advancement of structural changes in their industries on the basis of the increase in the share of advanced technologies in total industrial production, labour, added value, and surplus. In the times of the knowledge-based economy the ability to produce high-tech goods, the demand for which is growing much faster than for traditional goods, indicates the level of modernity of industry. The dynamic growth of the demand for knowledge-based high-tech goods results from the evolution of consumer habits, which are predominantly driven by educated and rich societies who demand that their sophisticated needs met. An important role in stimulating this demand is played by modern media as they instantly deliver information on the latest technical developments and are very efficient in transferring patterns of consumerism. The ability to adapt the structure of production to the needs of the market is crucial in defining a state's position in the international exchange of goods. This is due to the fact that the national technology is tightly interwoven with export abilities

A Dynamic Linkage between Financial Development, Energy Consumption and Economic Growth: Evidence from an Asymmetric and Nonlinear ARDL Model

Developing countries, including Pakistan, need a considerable effort to withstand economic growth; however, these countries have to cope with greenhouse gases emission and other environmental concerns. Financial advancement gives rise to modern, sometimes even innovative and energy-efficient technologies and, thus, contributes to a decline in energy usage among market entities: organizations and households. The current study explores the nonlinear asymmetric relationship between economic growth (Y) and the selected exogenous variables in Pakistan by incorporating time series data spanning from 1971 to 2016. Economic growth was considered as a target variable, while energy consumption (EC), electric power consumption (EPC), financial development (FD), and energy imports (EM) were considered independent variables. To investigate cointegration among the given variables, a nonlinear ARDL bound testing approach was employed. BDS independence test was used to check the nonlinearity, and a structural break unit root test was used for testing data stationarity. The findings confirm the presence of co-integration in the selected variables. A symmetric unidirectional significant causality exists running from EPC to Y, while a bidirectional symmetric causality was found between FD and Y. In contrast, any negative shocks in EPC, FD, and EM were found to have a positive asymmetric effect on Y. Meanwhile, a neutral effect was found between EC and Y. The outcomes of this study can provide guidelines for future re-searchers and policymakers. © 2021 by the authors. Licensee MDPI, Basel, Switzerland