Study of DNA-deltamethrin binding by voltammetry, competitive fluorescence, thermal denaturation, circular dichroism, and atomic force microscopy techniques

The interaction of deltamethrin (DM), a synthetic insecticide, with calf thymus DNA was studied. The cyclic voltammetric (CV) results revealed that DM has two irreversible cathodic peaks. The first peak (a) was devoted to reduction of -CN by 4 electrons and the second peak (b) was devoted to reduction of the -C = C- moiety by two electrons. By using non-linear regression analysis of CV data of peak (a), the binding constant, binding site size, and diffusion coefficient for free DM (D(f)) and DNA-DM (D(b)) were calculated as: 2.6 × 10(4), 1.6, 3.2 × 10(-4)Cm(2) S(-1), and 8.5 × 10(-6)Cm(2) S(-1), respectively. The thermal denaturation, competitive fluorescence, and AFM results revealed that the mode of interaction may be non-intercalative. Also the circular dichroism spectra showed that the conformation of CT DNA was converted from right-handed B-DNA to A-DNA due to the destacking of the adjacent guanine bases in pH 7.3 solution.     

The relationship between antioxidant compounds contents and antioxidant enzymes under water-deficit stress in the three Iranian cultivars of basil (<Emphasis Type="Italic">Ocimum basilicum</Emphasis> L.)

The current investigation was conducted to elucidate the potential modulatory functions of both enzymatic and non-enzymatic scavenging elements of three Iranian basil (Ocimum basilicum L.) cultivars in response to different water-deficit stress treatments [i.e., control (W1: 100 % FC), mild (W2: 75 % FC), moderate (W3: 50 % FC), and severe (W4: 25 % FC)]. In general, the growth parameters, viz., plant height, number of lateral branches, number of flowers in the inflorescence per plant, and dry and fresh weights of leaves and inflorescence followed by yield were considerably affected by water-deficit stress levels (p ≤ 0.05), though some fluctuations were observed among three cultivars. Under severe water-deficit stress (W4), total chlorophyll content overall increased, while a pronounced reduction in the carotenoid content was observed by boosting of water-deficit stress intensities. Apart from some quantitative variations, ROS-scavenging enzymes, such as SOD, CAT, APX, GPX, and PPO, exhibited different behaviors versus different levels of water-deficit stress in the basil cultivars, concluding that their modulation could be a cultivar-dependent mechanism and stress-dependent mechanism. Among different metabolites detected in the essential oil of basil cultivars, both methyl chavicol and squalene were superior in the cultivars 2 and 3, while in cultivar 1, linalool and squalene were the predominant constituents, under water deprivation conditions. Taking all the features studied here into consideration, presumably, cultivar 1 is qualified enough to nominate as the most tolerant basil cultivar, could be accordingly utilized as a promising source/material for breeding programs of basil under drought stress, and possibly other abiotic stresses.     

Enhanced enzymatic cellulose degradation by cellobiohydrolases via product removal

Product inhibition by cellobiose decreases the rate of enzymatic cellulose degradation. The optimal reaction conditions for two Emericella (Aspergillus) nidulans-derived cellobiohydrolases I and II produced in Pichia pastoris were identified as CBHI: 52 °C, pH 4.5–6.5, and CBHII: 46 °C, pH 4.8. The optimum in a mixture of the two was 50 °C, pH 4.9. An almost fourfold increase in enzymatic hydrolysis yield was achieved with intermittent product removal of cellobiose with membrane filtration (2 kDa cut-off): The conversion of cotton cellulose after 72 h was ~19 % by weight, whereas the conversion in the parallel batch reaction was only ~5 % by weight. Also, a synergistic effect, achieving ~27 % substrate conversion, was obtained by addition of endo-1,4-β-d-glucanase. The synergistic effect was only obtained with product removal. By using pure, monoactive enzymes, the work illustrates the profound gains achievable by intermittent product removal during cellulose hydrolysis.     

Rice diversity panel provides accurate genomic predictions for complex traits in the progenies of biparental crosses involving members of the panel

Key message

Rice breeding programs based on pedigree schemes can use a genomic model trained with data from their working collection to predict performances of progenies produced through rapid generation advancement.

Abstract

So far, most potential applications of genomic prediction in plant improvement have been explored using cross validation approaches. This is the first empirical study to evaluate the accuracy of genomic prediction of the performances of progenies in a typical rice breeding program. Using a cross validation approach, we first analyzed the effects of marker selection and statistical methods on the accuracy of prediction of three different heritability traits in a reference population (RP) of 284 inbred accessions. Next, we investigated the size and the degree of relatedness with the progeny population (PP) of sub-sets of the RP that maximize the accuracy of prediction of phenotype across generations, i.e., for 97 F₅–F₇ lines derived from biparental crosses between 31 accessions of the RP. The extent of linkage disequilibrium was high (r ² = 0.2 at 0.80 Mb in RP and at 1.1 Mb in PP). Consequently, average marker density above one per 22 kb did not improve the accuracy of predictions in the RP. The accuracy of progeny prediction varied greatly depending on the composition of the training set, the trait, LD and minor allele frequency. The highest accuracy achieved for each trait exceeded 0.50 and was only slightly below the accuracy achieved by cross validation in the RP. Our results thus show that relatively high accuracy (0.41–0.54) can be achieved using only a rather small share of the RP, most related to the PP, as the training set. The practical implications of these results for rice breeding programs are discussed.

     

Oxytocin infusion increases charitable donations regardless of monetary resources

This study examined if the prosocial effects of oxytocin (OT) extend from individuals to a generalized other who is in need. Participants played a series of economic games to earn money and were presented with an opportunity to donate a portion of their earnings to charity. OT did not significantly increase the decision to donate, but among the 36% of participants who did donate, people infused with OT were found to donate 48% more to charity than those given a placebo. The amount of money earned in the experiment had no effect on whether or not a donation was made or the size of a donation. This is the first study showing that OT increases generosity in unilateral exchanges directed toward philanthropic social institutions, as opposed to immediate benefits directed at individuals or groups.     

Scanning electron microscopic surface analysis of cryoconserved skull bone after decompressive craniectomy

Bone flaps removed during decompressive craniectomy are commonly frozen at ?80 °C and stored until cranioplasty. Histological integrity and regenerative capacity have been shown for cryoconserved bone. The effects of cryoconservation on the surface structure are unknown, although these might cause mechanical instability or facilitate bacterial adhesion. This study evaluates the surface structure of cryoconserved bone by scanning electron microscopy. Five patients were identified who could not receive their autologous bone flaps after decompressive craniectomy. These redundant bone specimens were obtained after cryoconservation for 6–8 months and the outer surface was analyzed by scanning electron microscopy. We found varying surface structures which did not correlate with any variables, such as patient age, gender or duration of freezing, and probably reflect physiological interindividual variation. Pathological findings, such as microscopic crack formation, were not observed. Cryoconservation for up to 8 months does not appear to alter the surface structure of skull bone on scanning electronic microscopy.     

NK cells: An attractive candidate for cancer therapy

Natural killer (NK) cells have significant capability in tumor immune-surveillance. The ability of lyse transformed cells immediately in an antigen-independent manner make them an attractive candidate for cancer cell therapy. Despite employment of NK cells in cancer immunotherapy, clinical trials are faced with serious limitations such as trouble with the penetration of NK cells in tumor sites, limited in vivo persistence, and tumor microenvironment interference. Taken together, the NK-cell cancer therapy is still infant scenario that has a long way to be translated in clinic. Current article first reviews characteristic features of NK lymphocytes. Then, it discusses about important disruptive barriers and motivator in the developmental stages of NK cells like as tumor microenvironment. Finally, some revolutionary approaches are highlighted utilizing of NK cells in cancer therapy.     

Quantitative evaluation of the cell penetrating properties of an iodinated Tyr-l-maurocalcine analog

L-Maurocalcine (L-MCa) is the first reported animal cell-penetrating toxin. Characterizing its cell penetration properties is crucial considering its potential as a vector for the intracellular delivery of drugs. Radiolabeling is a sensitive and quantitative method to follow the cell accumulation of a molecule of interest. An L-MCa analog containing an additional N-terminal tyrosine residue (Tyr-L-MCa) was synthesized, shown to fold and oxidize properly, and successfully radioiodinated to ¹²⁵I-Tyr-L-MCa. Using various microscopy techniques, the average volume of the rat line F98 glioma cells was evaluated at 8.9 to 18.9 × 10⁻⁷ μl. ¹²⁵I-Tyr-L-MCa accumulates within cells with a dose-dependency similar to the one previously published using 5,6-carboxyfluorescein-L-MCa. According to subcellular fractionation of F98 cells, plasma membranes keep less than 3% of the peptide, regardless of the extracellular concentration, while the nucleus accumulates over 75% and the cytosol around 20% of the radioactive material. Taking into account both nuclear and cytosolic fractions, cells accumulate intracellular concentrations of the peptide that are equal to the extracellular concentrations. Estimation of ¹²⁵I-Tyr-L-MCa cell entry kinetics indicate a first rapid phase with a 5 min time constant for the plasma membrane followed by slower processes for the cytoplasm and the nucleus. Once inside cells, the labeled material no longer escapes from the intracellular environment since 90% of the radioactivity remains 24 h after washout. Dead cells were found to have a lower uptake than live ones. The quantitative information gained herein will be useful for better framing the use of L-MCa in biotechnological applications. This article is part of a Special Issue entitled: Calcium Signaling in Health and Disease. Guest Editors: Geert Bultynck, Jacques Haiech, Claus W. Heizmann, Joachim Krebs, and Marc Moreau.     

Production of Soluble and Functional Anti-TNF-α Fab' Fragment in Cytoplasm of E. coli: Investigating the Effect of Process Conditions on Cellular Biomass and Protein Yield Using Response Surface Methodology

The Protein Journal - With the increasing dominance of monoclonal antibodies (mAbs) in the biopharmaceutical industry and smaller antibody fragments bringing notable advantages over full-length...