The antioxidant acetylcysteine reduces oxidative stress by decreasing level of AOPPs

Oxidative stress and especially its connection with many diseases has been discussed much recently. Among markers of oxidative stress there appear new and quite specific ones called advanced oxidation protein products (AOPPs). We tried to influence the level of AOPPs by an antioxidant therapy with N-acetylcysteine. Fourteen individuals with many cardiovascular risk factors were examined. All these patients were administered acetylcysteine (NAC) 600 mg/day orally during 20 days. Before starting the therapy we determined AOPP, albumin cobalt binding (ACB), glucose, creatinine, urea, ALT, AST, cholesterol, LDL, HDL and triglycerides values in peripheral venous blood in all individuals. After finishing our intervention we determined AOPP, ACB and glucose level again. Our results show a statistically significant decrease in AOPP levels after 20-day N-acetylcysteine therapy (medians, initially 82.2, at study end 74.3 umol/l, p = 0.039). We demonstrate a significant decrease in AOPP levels after 20-day N-acetylcysteine therapy in dose 600 mg/day.     

Normalization of single-channel DNA array data by principal component analysis

MOTIVATION: Detailed comparison and analysis of the output of DNA gene expression arrays from multiple samples require global normalization of the measured individual gene intensities from the different hybridizations. This is needed for accounting for variations in array preparation and sample hybridization conditions. RESULTS: Here, we present a simple, robust and accurate procedure for the global normalization of datasets generated with single-channel DNA arrays based on principal component analysis. The procedure makes minimal assumptions about the data and performs well in cases where other standard procedures produced biased estimates. It is also insensitive to data transformation, filtering (thresholding) and pre-screening.     

Production and characterization of monoclonal immunoglobulin A antibodies directed against Salmonella H:g,m flagellar antigen

Hybridomas were generated after intragastral immunization of BALB/c mice with live Salmonella suberu and subsequent fusion between isolated spleen lymphoblasts and myeloma cells. Three monoclonal antibodies (MAbs) of immunoglobulin A (IgA) isotype were selected and characterized. All of them were found to recognize the H:g epitope in enzyme-linked immunosorbent assay and immunoblotting but did not react with all H:g-expressing strains in slide agglutination test. All MAbs strongly agglutinated Salmonella enteritidis type strain and a large number of S. enteritidis clinical isolates. They were not bactericidal in the presence of complement. All hybridoma clones produced secretory IgA forms, which were found in the gastrointestinal tract of mice bearing hybridoma as a subcutaneous 'backpack' tumor or after intravenous application of purified MAbs. The IgA MAbs stability demonstrated in different tests together with their antigen specificity and strong agglutination ability make them a useful diagnostic tool for serotyping of Salmonella strains.     

FireProt: Energy- and Evolution-Based Computational Design of Thermostable Multiple-Point Mutants

There is great interest in increasing proteins’ stability to enhance their utility as biocatalysts, therapeutics, diagnostics and nanomaterials. Directed evolution is a powerful, but experimentally strenuous approach. Computational methods offer attractive alternatives. However, due to the limited reliability of predictions and potentially antagonistic effects of substitutions, only single-point mutations are usually predicted in silico, experimentally verified and then recombined in multiple-point mutants. Thus, substantial screening is still required. Here we present FireProt, a robust computational strategy for predicting highly stable multiple-point mutants that combines energy- and evolution-based approaches with smart filtering to identify additive stabilizing mutations. FireProt’s reliability and applicability was demonstrated by validating its predictions against 656 mutations from the ProTherm database. We demonstrate that thermostability of the model enzymes haloalkane dehalogenase DhaA and γ-hexachlorocyclohexane dehydrochlorinase LinA can be substantially increased (ΔT _m = 24°C and 21°C) by constructing and characterizing only a handful of multiple-point mutants. FireProt can be applied to any protein for which a tertiary structure and homologous sequences are available, and will facilitate the rapid development of robust proteins for biomedical and biotechnological applications.     

Relics of the Europe's warm past: phylogeography of the Aesculapian snake

Understanding how species responded to past climate change can provide information about how they may respond to the current global warming. Here we show how a European reptile species responded to the last natural global warming event at the Pleistocene-Holocene transition that led to the Holocene climatic optimum approximately 5000-8000 years ago. The Aesculapian snake, Zamenis longissimus, is a thermophilous species whose present-day distribution in the southern half of Europe is a remnant of much wider range during the Holocene climatic optimum when populations occurred as far north as Denmark. These northern populations went extinct as the climate cooled, and presently the species is extinct from all central Europe, except few relic populations in locally suitable microhabitats in Germany and the Czech Republic. Our phylogenetic and demographic analyses identified two major clades that expanded from their respective western and eastern refugia after the last glacial maximum (18,000-23,000 years ago) and contributed approximately equally to the present range. Snakes from the relic northern populations carried the Eastern clade, showing that it was primarily the snakes from the eastern, probably Balkan, refugium that occupied the central and northern Europe during the Holocene climatic optimum. Two small, deep-branching clades were identified in near the Black Sea and in Greece. These clades provide evidence for two additional refugia, which did not successfully contribute to the colonization of Europe. If, as our results suggest, some populations responded to the mid-Holocene global warming by shifting their ranges further north than other populations of the same species, knowing what populations were able to expand in different species may provide information about what populations will be important for the species' ability to cope with the current global warming.     

Bilayer structural destabilization by low amounts of chlorophyll a

The present study shows that small admixtures of one chlorophyll a (Chla) molecule per several hundred lipid molecules have strong destabilizing effect on lipid bilayers. This effect is clearly displayed in the properties of the L_α-H_II transformations and results from a Chla preference for the H_II relative to the L_α phase. Chla disfavors the lamellar liquid crystalline phase L_α and induces its replacement with inverted hexagonal phase H_II, as is consistently demonstrated by DSC and X-ray diffraction measurements on phosphatidylethanolamine (PE) dispersions. Chla lowers the L_α-H_II transition temperature (42 °C) of the fully hydrated dipalmitoleoyl PE (DPoPE) by ∼ 8 °C and ∼ 17 °C at Chla/DPoPE molar ratios of 1:500 and 1:100, respectively. Similar Chla effect was recorded also for dielaidoyl PE dispersions. The lowering of the transition temperature and the accompanying significant loss of transition cooperativity reflect the Chla repartitioning and preference for the H_II phase. The reduction of the H_II phase lattice constant in the presence of Chla is an indication that Chla favors H_II phase formation by decreasing the radius of spontaneous monolayer curvature, and not by filling up the interstitial spaces between the H_II phase cylinders. The observed Chla preference for H_II phase and the substantial bilayer destabilization in the vicinity of a bilayer-to-nonbilayer phase transformation caused by low Chla concentrations can be of interest as a potential regulatory or membrane-damaging factor.     

Ploidy-specific interactions of three host plants with arbuscular mycorrhizal fungi: Does genome copy number matter?

? Premise of the study: Polyploidy has been shown to affect different plant traits and modulate interactions between plants and other organisms, such as pollinators and herbivores. However, no information is available on whether it can also shape the functioning of mycorrhizal symbiosis. ? Methods: The mycorrhizal growth response was assessed for three angiosperms with intraspecific ploidy variation. Different cytotypes of Aster amellus, Campanula gentilis, and Pimpinella saxifraga were either left uninoculated or were inoculated with arbuscular mycorrhizal (AM) fungi in a pot experiment. After 3 mo of cultivation in a greenhouse, plant growth, phosphorus concentration in the shoot biomass, and development of the AM symbiosis were evaluated. ? Key results: No significant ploidy-specific differences in AM development were recorded. The inoculation led to consistently greater phosphorus uptake; however, the effect on plant growth differed considerably among plant species, populations, ploidy levels, and AM species. A salient ploidy-specific response was observed in A. amellus. Whereas diploid plants benefited from AM inoculation, the hexaploids consistently showed negative or no-growth responses (depending on the AM species). In contrast to A. amellus, no interactions between inoculation and ploidy were observed in C. gentilis and P. saxifraga. ? Conclusions: The first evidence is provided of a ploidy-specific response of a mycotrophic plant to AM fungi. Our results demonstrate the complexity of interaction between plants and associated AM fungi, with the ploidy level of the host plant being one component that may modulate the functioning of the symbiosis.     

The first genomewide interaction and locus-heterogeneity linkage scan in bipolar affective disorder: strong evidence of epistatic effects between loci on chromosomes 2q and 6q

We present the first genomewide interaction and locus-heterogeneity linkage scan in bipolar affective disorder (BPAD), using a large linkage data set (52 families of European descent; 448 participants and 259 affected individuals). Our results provide the strongest interaction evidence between BPAD genes on chromosomes 2q22-q24 and 6q23-q24, which was observed symmetrically in both directions (nonparametric LOD [NPL] scores of 7.55 on 2q and 7.63 on 6q; P<.0001 and P=.0001, respectively, after a genomewide permutation procedure). The second-best BPAD interaction evidence was observed between chromosomes 2q22-q24 and 15q26. Here, we also observed a symmetrical interaction (NPL scores of 6.26 on 2q and 4.59 on 15q; P=.0057 and .0022, respectively). We covered the implicated regions by genotyping additional marker sets and performed a detailed interaction linkage analysis, which narrowed the susceptibility intervals. Although the heterogeneity analysis produced less impressive results (highest NPL score of 3.32) and a less consistent picture, we achieved evidence of locus heterogeneity at chromosomes 2q, 6p, 11p, 13q, and 22q, which was supported by adjacent markers within each region and by previously reported BPAD linkage findings. Our results provide systematic insights in the framework of BPAD epistasis and locus heterogeneity, which should facilitate gene identification by the use of more-comprehensive cloning strategies.