N-acetylcysteine versus progesterone on the cisplatin-induced peripheral neurotoxicity

Background: Cisplatin-induced peripheral nerve neurotoxicity (CIPN) is the main obstacle in cisplatin treatment. The aim of this study was to compare the modulatory effects of N-acetylcysteine (NAC) and progesterone on CIPN, because there are scarce literature data on the protective effect of the proge­sterone on the CIPN. Materials and methods: Twenty-four rats were divided into four groups: control, cisplatin-treated, concomitant cisplatin-treated and NAC-treated, and concomitant cisplatin-treated and progesterone-treated. Electron microscopic, immunohistochemical, real time polymerase chain reaction and histomorphome­tric analysis; oxidative/antioxidative markers (MDA/GSH and SOD), neurotoxic/ neuroprotective markers (iNOS/nNOS), inflammatory mediators (TNF-a and NF-kB) and BAX were done. Results: The myelin sheath in the cisplatin-treated group elucidated infolding. The myelin was disfigured, degenerated, and extensively split with areas of focal loss. The axoplasm was atrophic. Ballooning and vacuolations of the mitochon­dria with alterations of Remak bundles structures were observed. Fewer of these changes were noted in the NAC and progesterone-treated groups. Decrease of the antioxidant SOD and GSH (81% and 64%) and increase of the oxidant MDA (9 folds), increment of the neurotoxic iNOS (1.9 folds) and decrement of the neuroprotective nNOS (64%) and elevation of the inflammatory mediators’ TNF-a and NF-kB (8.3 and 11 folds) in the cisplatin-treated group. Increase of the antioxidant SOD (1.3 and 2.5 folds) and GSH (120% and 79%) and decrease of the oxidant MDA (69% and 88%), decrement of the neurotoxic iNOS (56% and 68%) and increment of the neuroprotective nNOS (1.6 and one folds) and elevation of the inflammatory mediators’ TNF-a and NF-kB were observed in the NAC and progesterone-treated groups, respectively. Conclusions: The toxic effect of CIPN might be attributed to either oxidative or severe inflammatory stress. Progesterone is efficient in ameliorating these effects; however, NAC is better. (Folia Morphol 2018; 77, 2: 234–245

FPGA Implemetation of Acquisition phase of the GPS Receiver using XSG

In the past it was usual to exert a huge effort in the design, simulation, and the real time implementation of the complicated electronic and communication systems, like GNSS receivers. The complexity of the system algorithms combined with the complexity of the available tools created a system that is difficult to track down for debugging or for redesign. So, the simulation and educational tools was different from the prototyping tools. In this paper the parallel search acquisition phase of a GPS receiver was simulated and implemented on FPGA using the same platform and through a graphical programming language. So this paper introduces the fruit of integrating the prototyping tools with the simulation tools as a single platform through which the complicated electronic systems can be simulated and prototyped

Diversified glucosinolate metabolism:biosynthesis of hydrogen cyanide and of the hydroxynitrile glucoside alliarinoside in relation to sinigrin metabolism in <i>Alliaria petiolata</i>

Alliaria petiolata (garlic mustard, Brassicaceae) contains the glucosinolate sinigrin as well as alliarinoside, a γ-hydroxynitrile glucoside structurally related to cyanogenic glucosides. Sinigrin may defend this plant against a broad range of enemies, while alliarinoside confers resistance to specialized (glucosinolate-adapted) herbivores. Hydroxynitrile glucosides and glucosinolates are two classes of specialized metabolites, which generally do not occur in the same plant species. Administration of [UL-(14)C]-methionine to excised leaves of A. petiolata showed that both alliarinoside and sinigrin were biosynthesized from methionine. The biosynthesis of alliarinoside was shown not to bifurcate from sinigrin biosynthesis at the oxime level in contrast to the general scheme for hydroxynitrile glucoside biosynthesis. Instead, the aglucon of alliarinoside was formed from metabolism of sinigrin in experiments with crude extracts, suggesting a possible biosynthetic pathway in intact cells. Hence, the alliarinoside pathway may represent a route to hydroxynitrile glucoside biosynthesis resulting from convergent evolution. Metabolite profiling by LC-MS showed no evidence of the presence of cyanogenic glucosides in A. petiolata. However, we detected hydrogen cyanide (HCN) release from sinigrin and added thiocyanate ion and benzyl thiocyanate in A. petiolata indicating an enzymatic pathway from glucosinolates via allyl thiocyanate and indole glucosinolate derived thiocyanate ion to HCN. Alliarinoside biosynthesis and HCN release from glucosinolate-derived metabolites expand the range of glucosinolate-related defenses and can be viewed as a third line of defense, with glucosinolates and thiocyanate forming protein being the first and second lines, respectively

The biosynthetic gene cluster for the cyanogenic glucoside dhurrin in <i>Sorghum bicolor</i> contains its co-expressed vacuolar MATE transporter

Genomic gene clusters for the biosynthesis of chemical defence compounds are increasingly identified in plant genomes. We previously reported the independent evolution of biosynthetic gene clusters for cyanogenic glucoside biosynthesis in three plant lineages. Here we report that the gene cluster for the cyanogenic glucoside dhurrin in Sorghum bicolor additionally contains a gene, SbMATE2, encoding a transporter of the multidrug and toxic compound extrusion (MATE) family, which is co-expressed with the biosynthetic genes. The predicted localisation of SbMATE2 to the vacuolar membrane was demonstrated experimentally by transient expression of a SbMATE2-YFP fusion protein and confocal microscopy. Transport studies in Xenopus laevis oocytes demonstrate that SbMATE2 is able to transport dhurrin. In addition, SbMATE2 was able to transport non-endogenous cyanogenic glucosides, but not the anthocyanin cyanidin 3-O-glucoside or the glucosinolate indol-3-yl-methyl glucosinolate. The genomic co-localisation of a transporter gene with the biosynthetic genes producing the transported compound is discussed in relation to the role self-toxicity of chemical defence compounds may play in the formation of gene clusters

Wax co-cracking synergism of high density polyethylene to alternative fuels

AbstractAttempts have been made to understand the thermal degradation of high density polyethylene (HDPE) and their combined co-cracking using different ratios of HDPE and petroleum wax under nitrogen atmosphere. We have conducted the experiments using HDPE as the raw material and petroleum wax as co-feed by at 400 and 450°C reaction temperatures. The product distribution was noted along with reaction time of 0.5–3h for the degradation. Thermal gravimetric analysis (TGA) technique was used to measure the weight change of the feedstock as a function of temperature and time. Differential scanning calorimetry (DSC) was used to determine the degradation temperature. Products were characterized using gas chromatography (GC) and infrared spectroscopy (FTIR), some other standard physical methods were used to determine the main properties of the liquid products. Results show that the mixed plastic-wax samples could be converted into gases, gasoline, and middle distillate depending upon the composition of feed polymer/wax ratio. It was found that the products mostly consisted of paraffin and olefin compounds, with carbon numbers of C1–C4, C5–C9 and C10–C19 in the case of gases, gasoline and middle distillate respectively

Fusion of ferredoxin and cytochrome P450 enables direct light-driven biosynthesis

[Image: see text] Cytochrome P450s (P450s) are key enzymes in the synthesis of bioactive natural products in plants. Efforts to harness these enzymes for in vitro and whole-cell production of natural products have been hampered by difficulties in expressing them heterologously in their active form, and their requirement for NADPH as a source of reducing power. We recently demonstrated targeting and insertion of plant P450s into the photosynthetic membrane and photosynthesis-driven, NADPH-independent P450 catalytic activity mediated by the electron carrier protein ferredoxin. Here, we report the fusion of ferredoxin with P450 CYP79A1 from the model plant Sorghum bicolor, which catalyzes the initial step in the pathway leading to biosynthesis of the cyanogenic glucoside dhurrin. Fusion with ferredoxin allows CYP79A1 to obtain electrons for catalysis by interacting directly with photosystem I. Furthermore, electrons captured by the fused ferredoxin moiety are directed more effectively toward P450 catalytic activity, making the fusion better able to compete with endogenous electron sinks coupled to metabolic pathways. The P450-ferredoxin fusion enzyme obtains reducing power solely from its fused ferredoxin and outperforms unfused CYP79A1 in vivo. This demonstrates greatly enhanced electron transfer from photosystem I to CYP79A1 as a consequence of the fusion. The fusion strategy reported here therefore forms the basis for enhanced partitioning of photosynthetic reducing power toward P450-dependent biosynthesis of important natural products

Vanillin formation from ferulic acid in <em>Vanilla planifolia</em> is catalysed by a single enzyme

Vanillin is a popular and valuable flavour compound. It is the key constituent of the natural vanilla flavour obtained from cured vanilla pods. Here we show that a single hydratase/lyase type enzyme designated vanillin synthase (VpVAN) catalyses direct conversion of ferulic acid and its glucoside into vanillin and its glucoside, respectively. The enzyme shows high sequence similarity to cysteine proteinases and is specific to the substitution pattern at the aromatic ring and does not metabolize caffeic acid and p-coumaric acid as demonstrated by coupled transcription/translation assays. VpVAN localizes to the inner part of the vanilla pod and high transcript levels are found in single cells located a few cell layers from the inner epidermis. Transient expression of VpVAN in tobacco and stable expression in barley in combination with the action of endogenous alcohol dehydrogenases and UDP-glucosyltransferases result in vanillyl alcohol glucoside formation from endogenous ferulic acid. A gene encoding an enzyme showing 71% sequence identity to VpVAN was identified in another vanillin-producing plant species Glechoma hederacea and was also shown to be a vanillin synthase as demonstrated by transient expression in tobacco. (Résumé d'auteur