Influence of cytokinins and novel cytokinin antagonists on the senescence of detached leaves of <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis>

Cytokinins N⁶-benzyladenine (BA) and 1-(2-chloropyridin-4-yl)-3-phenylurea (4PU-30) delayed the senescence of detached leaves (3^rd to 7^th leaf node) of wild and ethylene insensitive eti5 mutant of Arabidopsis thaliana. The novel anticytokinins, structural analogues of purine and phenylurea cytokinins also affected the senescence of detached rosette leaves of A. thaliana. They diminished to a significant extent the cytokinin-induced delay of chlorophyll destruction, but without a considerable difference in their action against both types of cytokinins. These results correlated with changes observed in ribonuclease (RNase) activity.     

Toll-like receptor 4 mediates vascular remodeling in hyperhomocysteinemia

Nephrotic syndrome (NS) is a kidney disease predominantly present in children with idiopathic condition; final stage of the disease progresses into end-stage renal disease. Generally, NS is treated using standard steroid therapy, however; most of the children are steroid sensitive and about 15–20% are non-responders (SRNS). Non-responsiveness of these children would be a risk with the possibility of mutational changes in podocyte genes (NPHS1, NPHS2, WT1, PLCE1). The mutation in podocyte genes is associated with SRNS. NPHS1, NPHS2, and WT1 genes are identified/directly linked to SRNS. The present study is a surveillance on the mutation analysis of WT1 (exons 8 and 9) and NPHS2 (exons 1–8) gene in SRNS followed by clinical management. In the present study, we analyzed these two genes in a total of 117 SRNS (73 boys and 44 girls) children. A total of five mutations were detected in six children. First, WT1 mutation was detected at 9th intron-IVS 9 + 4C > T position in one SRNS female patient. This WT1 mutation was identified in a girl having Frasier Syndrome (FS) with focal segmental glomerulosclerosis and a complete sex reversal found through molecular and karyological screening. In NPHS2, missense mutations of P20L (in two children), P316S, and p.R229Q, and a frame shift mutation of 42delG were detected. Thus, applying molecular investigation helped us to decide on treatment plan of SRNS patients, mainly to avoid unnecessary immunosuppressive treatment.     

Sesquiterpene lactones as chemotaxonomic markers in genus Anthemis

Sesquiterpene lactones isolated from the genus Anthemis are used as chemotaxonomic markers. The obtained results support with some exceptions the botanical classification in Flora Europaea. Discrepancy between the lactone profile, cluster analysis and classification of A. melampodina, A. macedonica and A. austriaca in the genus Anthemis is discussed. The lactone composition of the undescribed as an European species A. plutonia correlates well with the guaianolide containing group of sect. Hiorthia.     

Effect of Plant Type on the Persistence of Beauveria bassiana

Field evaluation of isolate MK 2001 of the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin, revealed conidia persistence and infectivity up to 26 days on foliage of lettuce and celery, two crops with substantial plant differences. Plants were treated at a rate of 100 ml/cage at a concentration of 1×10⁸ conidia/ml. The number of colony-forming units (CFU) recovered immediately after treatments from discs sampled on lettuce and celery leaves were not significantly different, due to similar foliar coverage of conidia by application. Significant differences were observed between both host plants during the 26 days of the field trial. The number of CFUs recovered on lettuce was significantly higher than that on celery leaves. However, for each host plant, there were no significant differences either between lettuce external leaves and internal leaves or between celery canopy and bottom leaves. An in vitro pathogenicity test carried out on Lygus lineolaris adults fed with leaf discs harvested from treated cages resulted in a high pathogenicity of B. bassiana isolate MK 2001. The mortality immediately after treatment did not differ from the death counts taken every other day for 26 days. However, efficacy was significantly different between both plants. Mortality was 91% on lettuce and 78% on celery, 7 days post-treatment. This study highlighted that plant type must be taken into account in foliar application of B. bassiana.     

The effect of thermal treatment on antibacterial properties of nanostructured TiO<Subscript>2</Subscript>(N) films illuminated with visible light

This work focuses on the photocatalytic performances and antibacterial activity of nitrogen doped TiO₂ nanosystems with three and five layers obtained by a sol-gel route, followed by thermal treatment in oxygen or ammonia atmosphere at temperatures between 400 and 1000°C. Subsequently, the antibacterial activity of the obtained nanosystems on the Escherichia coli cells are determined and discussed. The obtained results show a significant dependence of the functional performances on the system’s composition. In particular, the antimicrobial activity of nitrogen-doped TiO₂ films is correlated with the temperature of thermal treatment and illumination time with visible artificial light.     

Enzymatic conversion of sunflower oil to biodiesel in a solvent-free system: Process optimization and the immobilized system stability

The feasibility of using the commercial immobilized lipase from Candida antarctica (Novozyme 435) to synthesize biodiesel from sunflower oil in a solvent-free system has been proved. Using methanol as an acyl acceptor and the response surface methodology as an optimization technique, the optimal conditions for the transesterification has been found to be: 45 ^oC, 3% of enzyme based on oil weight, 3:1 methanol to oil molar ratio and with no added water in the system. Under these conditions, >99% of oil conversion to fatty acid methyl ester (FAME) has been achieved after 50 h of reaction, but the activity of the immobilized lipase decreased markedly over the course of repeated runs. In order to improve the enzyme stability, several alternative acyl acceptors have been tested for biodiesel production under solvent-free conditions. The use of methyl acetate seems to be of great interest, resulting in high FAME yield (95.65%) and increasing the half-life of the immobilized lipase by about 20.1 times as compared to methanol. The reaction has also been verified in the industrially feasible reaction system including both a batch stirred tank reactor and a packed bed reactor. Although satisfactory performance in the batch stirred tank reactor has been achieved, the kinetics in a packed bed reactor system seems to have a slightly better profile (93.6 ± 3.75% FAME yield after 8–10 h), corresponding to the volumetric productivity of 48.5 g/(dm³ h). The packed bed reactor has operated for up to 72 h with almost no loss in productivity, implying that the proposed process and the immobilized system could provide a promising solution for the biodiesel synthesis at the industrial scale.     

Design and synthesis of new stabilized combi-triazenes for targeting solid tumors expressing the epidermal growth factor receptor (EGFR) or its closest homologue HER2

The monoalkyltriazene moiety lends itself well to the design of combi-molecules. However, due to its instability under physiological conditions, efforts were directed towards stabilizing it by grafting a hydrolysable carbamate onto the 3-position. The synthesis and biological activities of these novel N-carbamyl triazenes are described.     

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.