Identification of hemagglutinin structural domain and polymorphisms which may modulate swine H1N1 interactions with human receptor

Background  

The novel A/H1N1 influenza virus, which recently emerged in North America is most closely related to North American H1N1/N2 swine viruses. Until the beginning of 2009, North American swine H1N1/N2 viruses have only sporadically infected humans as dead-end hosts. In 2009 the A/H1N1 virus acquired the capacity to spread efficiently by human to human transmission. The novel A/H1N1 influenza virus has struck thousands of people in more than 70 countries and killed more than 140, representing a public health emergency of international concern. Here we have studied properties of hemagglutinin of A/H1N1 which may modulate virus/receptor interaction.     

Different susceptibility of prefrontal cortex and hippocampus to oxidative stress following chronic social isolation stress

Chronic oxidative stress plays an important role in depression. The aim of present study was to examine the stress-induced changes in serum corticosterone (CORT) levels, cytosolic protein carbonyl groups, malondialdehyde (MDA), reduced glutathione (GSH), nitric oxide (NO) and total superoxide dismutase (SOD) activity in the prefrontal cortex versus hippocampus of male Wistar rats exposed to acute (2 h of immobilization or cold), chronic (21d of social isolation) stress, and their combination (chronic + acute stress). The subcellular distribution of nuclear factor-κB (NF-κB) and cytosolic cyclooxygenase 2 (COX-2) protein expressions were also examined. Depressive- and anxiety-like behaviors were assessed via the forced swim, sucrose preference, and marble burying tests in chronically isolated rats. Although both acute stressors resulted in elevated CORT, increased MDA in the prefrontal cortex and NF-κB activation accompanied by increased NO in the hippocampus were detected only following acute cold stress. Chronic isolation resulted in no change in CORT levels, but disabled appropriate response to novel acute stress and led to depressive- and anxiety-like behaviors. Increased oxidative/nitrosative stress markers, likely by NF-κB nuclear translocation and concomitant COX-2 upregulation, associated with decreased SOD activity and GSH levels, suggested the existence of oxidative stress in the prefrontal cortex. In contrast, hippocampus was less susceptible to oxidative damage showing only increase in protein carbonyl groups and depleted GSH. Taken together, the prefrontal cortex seems to be more sensitive to oxidative stress than the hippocampus following chronic isolation stress, which may be relevant for further research related to stress-induced depressive-like behavior.     

Oxidative stress in rheumatoid arthritis patients: relationship to diseases activity

The aim of this study was to assess the oxidative stress status in rheumatoid arthritis (RA) by measuring markers of free radical production, systemic activity of disease, and levels of antioxidant. 52 RA patients and 30 healthy controls were included in the study, and clinical examination and investigations were performed and disease activity was assessed. Peripheral blood samples were used for all the assays. We assessed the markers of oxidative stress, including plasma levels of index of lipid peroxidation-thiobarbituric acid reactive substances (TBARS), hydrogen peroxide (H₂O₂), superoxide anion radical (O₂ ^?), nitric oxide (NO), and superoxide dismutase activity (SOD), catalase activity (CAT) and glutathione levels in erythrocytes. In the RA group, levels of H₂O₂, O₂ ^?, and TBARS were significantly higher than in controls (4.08 ± 0.31 vs. 2.39 ± 0.13 nmol/l, p < 0.01; 8.90 ± 1.28 vs. 3.04 ± 0.38 nmol/l, p < 0.01, 3.65 ± 0.55 vs. 1.06 ± 0.17 μmol/l, p < 0.01). RA patients had significantly increased SOD activity compared with healthy controls (2,918.24 ± 477.14 vs. 643.46 ± 200.63UgHbx103, p < 0.001). Patients had significantly higher levels of pro-oxidants (O₂ ^?, H₂O₂, and TBARS) compared to controls, despite significantly higher levels of SOD. Significant differences were also observed in serum levels of NO in patients with high-diseases activity. Our findings support an association between oxidative/nitrosative stress and RA. Stronger response in samples with higher diseases activity suggests that oxidative/nitrosative stress markers may be useful in evaluating the progression of RA as well as in elucidating the mechanisms of disease pathogenesis.     

Evolution and Molecular Epidemiology of Citrus tristeza virus on Crete: Recent Introduction of a Severe Strain

Sporadic incidences of Citrus tristeza virus (CTV) in western Crete resulting from the introduction of a mild strain (Spanish isolate T385) have been reported previously. Further analysis within this region has identified an emerging second CTV strain with minimal genetic divergence, sharing 99% nucleotide identity with the severe stem‐pitting isolate Taiwan‐Pum/SP/T1. Other severe isolates from the Mediterranean region appear in the same phylogenetic cluster, indicating movement or new introductions and the need for targeted control actions and improved phytosanitary measures in this area.     

Genetic variation and relationship of alfalfa populations and their progenies based on RAPD markers

The aim of investigation was to evaluate genetic variation and relationship among alfalfa populations and their offspring, with minimal cost, by using DNA marker analysis. RAPD analysis was performed on bulked DNA samples of five alfalfa parental populations and their progenies: 20 F1 populations from reciprocal diallel crosses and five S1 populations from self-pollination. Twenty primers generated 217 bands, ranging in size from 300 to 6000 bp, with the average number of bands per primer of 10.85 and polymorphism information content of 0.246. Percentage of polymorphic loci, effective number of alleles, expected heterozygosity and Shannon’s information index were used to estimate genetic variation. Higher diversity was observed in F1 progeny populations, while genetic variation in parental populations and S1 progenies remained similar. The genetic relatedness of alfalfa populations was analysed by UPGMA and Bayesian model-based clustering approach. In both types of analysis selfpollinated progenies were grouped. Furthermore, the hybrid offspring where Zuzana, and RSI 20 were maternal parents were placed in separate groups. The results indicate that use of RAPD markers on bulked DNA samples can be fast and cost-effective way for differentiation of alfalfa parental populations and their offspring, as well as for evaluation of their genetic relationships.     

Remedying the iron-deficient maize plants by new synthetic macromolecular chelating agents

The efficacy of Fe³⁺ complexes of polyethers with 8-quinolinol (8QOH) chelating groups attached to the polymer chain at different positions of the aromatic ring or having different chain length for remedying the iron-deficient maize plants was evaluated. The efficacy of chelates of polymers having terminal 8QOH residues was compared with that of complexes of ethylenediaminetetraacetic acid, 8QOH, mixtures of commercial polyethers with isopropylamino end-groups and 8QOH or FeCl₃.6H₂O. It was found that at 30/25 °C (day/night) and photosynthetic photon flux density 1100–1300 μmol m⁻² s⁻¹, the chlorotic maize plants recovered for 4 days of iron re-supply. An increase in the fresh and dry weight, leaf area, net photosynthetic CO₂ uptake of maize leaves, leaf pigment composition and chlorophyll fluorescence was more pronounced in the plants supplied with Fe³⁺ chelates of polymers bearing 8QOH groups attached at 5-position, compared to the other tested Fe³⁺complexes. The importance of the stability of Fe³⁺ complexes, structure of the chelating agent and the necessity of effective ligand exchange between synthetic chelators and free phytosiderophore in iron uptake by strategy II plants was discussed. This revised version was published online in June 2006 with corrections to the Cover Date.     

Magnesium supplementation and iron status among female students: The intervention study

BackgroundLiterature data indicate the benefit of magnesium (Mg) supplementation. The aim of this study was to examine the effect of short-term Mg supplementation on iron status in healthy female participants.MethodsOne hundred healthy female students of the University of Belgrade - Faculty of Pharmacy participated the study during eleven intervention days. Students ingested Mg preparations with the same dose of the active substance. The analysis included the measurement of serum iron, unsaturated iron binding capacity (UIBC), total iron binding capacity (TIBC), total Mg (tMg), ionized Mg (iMg), complete blood count, met-, carboxyand oxy-haemoglobin (metHgb, COHgb, O2Hgb). Transferrin concentrations and percentage of transferrin saturation (SAT) were calculated manually. The association among the analyzed biochemical parameters was examined using polynomial regression. A principal component analysis (PCA) was used for the evaluation of interdependence between the analyzed parameters.ResultsA statistically significant trend for change in O2Hgb (%) by tertiles of iMg concentrations was found (P = 0.029). Serum tMg reached significant positive correlation with the SAT at concentration levels greater than 0.9 mmol/L, after 11 days of intervention (R2=0.116). Ionized Mg in a concentration higher than 0.6 mmol/L is positively correlated with SAT and serum Fe (R2=0.214; 0.199, respectively). PCA revealed variability of 64.7% for two axes after 11 days.ConclusionsMg supplementation leads to an improvement in the certain iron status parameters even in individuals with optimal levels of these indices. However, caution should be exercised when supplementing Mg, and laboratory monitoring of the interaction is required.     

Novel,potent, selective,and metabolically stable stearoyl-CoA desaturase (SCD) inhibitors

We identified a series of structurally novel SCD (Δ9 desaturase) inhibitors via high-throughput screening and follow-up SAR studies. Modification of the central bicyclic scaffold has proven key to our potency optimization effort. The most potent analog (8g) had IC₅₀ value of 50 pM in a HEPG2 SCD assay and has been shown to be metabolically stable and selective against Δ5 and Δ6 desaturases.     

Genetic characterization of grey wolves (<Emphasis Type="Italic">Canis lupus</Emphasis> L. <Emphasis Type="Italic">1758</Emphasis>) from Bosnia and Herzegovina: implications for conservation

The grey wolves of Bosnia and Herzegovina form a subpopulation of the Dinaric-Balkan wolf population and represent one of Europe’s least studied wolf populations. Since the Dinaric-Balkan population is a valuable source of genetic diversity for neighboring populations, comprehensive assessments are warranted. We aimed to determine the genetic variability and structure of the grey wolf population from Bosnia and Herzegovina, as well as estimate levels of gene flow and inbreeding and evaluate genetic signals of a bottleneck. To do this, we analyzed the variability of eighteen microsatellite loci. We found moderately high genetic heterozygosity for wolves from Bosnia and Herzegovina, as described for other Dinaric-Balkan wolf populations. We reveal weak genetic structuring with two genetic clusters identified. Wolves from the eastern part of the region formed a relatively distinct cluster, whereas individuals in the second cluster overlapped quite considerably with admixed individuals. Despite the signal of genetic structure being weak, clustering of individuals from the eastern part of the country extended through all analyses. Thus, this cluster could be considered a separate management unit, perhaps requiring specific conservation attention.     

Physiological and cell ultrastructure disturbances in wheat seedlings generated by <Emphasis Type="Italic">Chenopodium murale</Emphasis> hairy root exudate

Chenopodium murale L. is an invasive weed species significantly interfering with wheat crop. However, the complete nature of its allelopathic influence on crops is not yet fully understood. In the present study, the focus is made on establishing the relation between plant morphophysiological changes and oxidative stress, induced by allelopathic extract. Phytotoxic medium of C. murale hairy root clone R5 reduced the germination rate (24% less than control value) of wheat cv. Nata?a seeds, as well as seedling growth, diminishing shoot and root length significantly, decreased total chlorophyll content, and induced abnormal root gravitropism. The R5 treatment caused cellular structural abnormalities, reflecting on the root and leaf cell shape and organization. These abnormalities mostly included the increased number of mitochondria and reorganization of the vacuolar compartment, changes in nucleus shape, and chloroplast organization and distribution. The most significant structural changes were observed in cell wall in the form of amoeboid protrusions and folds leading to its irregular shape. These structural alterations were accompanied by an oxidative stress in tissues of treated wheat seedlings, reflected as increased level of H₂O₂ and other ROS molecules, an increase of radical scavenging capacity and total phenolic content. Accordingly, the retardation of wheat seedling growth by C. murale allelochemicals may represent a consequence of complex activity involving both cell structure alteration and physiological processes.