Affinity labeling of bovine liver glutamate dehydrogenase with 8-[(4-bromo-2,3-dioxobutyl)thio]adenosine 5'-diphosphate and 5'-triphosphate

Bovine liver glutamate dehydrogenase reacts with 8-[(4-bromo-2,3-dioxobutyl)thio]adenosine 5'-diphosphate (8-BDB-TA-5'-DP) and 5'-triphosphate (8-BDB-TA-5'-TP) to yield enzyme with about 1 mol of reagent incorporated/mol of enzyme subunit. The modified enzyme is catalytically active but has decreased sensitivity to inhibition by GTP, reduced extent of activation by ADP, and diminished inhibition by high concentrations of NADH. Since modified enzyme, like native glutamate dehydrogenase, reversibly binds more than 1 mol each of ADP and GTP, it is unlikely that 8-BDB-TA-5'-TP reacts directly within either the ADP or GTP regulatory sites. The rate constant for reaction of enzyme exhibits a nonlinear dependence on reagent concentration with KD = 89 microM for 8-BDB-TA-5'-TP and 240 microM for 8-BDB-TA-5'-DP. The ligands ADP and GTP alone and NADH alone produce only small decreases in the rate constant for the reaction of enzyme with 8-BDB-TA-5'-TP, but the combined addition of 5 mM NADH + 200 microM GTP reduces the reaction rate constant more than 10-fold and the reagent incorporation to about 0.1 mol/mol of enzyme subunit. These results suggest that 8-BDB-TA-5'-TP reacts as a nucleotide affinity label in the region of the GTP-dependent NADH regulatory site of bovine liver glutamate dehydrogenase.     

Macrophage colony stimulating factor prevents NMDA-induced neuronal death in hippocampal organotypic cultures

Macrophage colony stimulating factor (M-CSF) and its receptor are up-regulated in the brain in Alzheimer's disease (AD), in transgenic mouse models for AD, and experimental models for traumatic and ischemic brain injury. M-CSF induces activation and proliferation of microglial cells and expression of proinflammatory cytokines. We examined the role of M-CSF in excitotoxic neuronal cell death in organotypic hippocampal cultures. NMDA treatment induced neuronal apoptosis and caspase-3 activation in organotypic hippocampal cultures, whereas treatment with M-CSF protected hippocampal neurons from NMDA-induced apoptosis. Caspase-3 activation was inhibited by M-CSF treatment to the same degree as with the caspase inhibitor Z-VAD-FMK. These results suggest that M-CSF has neuroprotective properties through inhibition of caspase-3 that could promote neuronal survival after excitotoxic insult. The role of M-CSF in neurological disease should be reevaluated as a microglial activator with potentially neuroprotective effects.     

Effect of Pyrolysis Temperature on Chemical and Surface Properties of Biochar of Rapeseed (Brassica napus L.)

The biochar is an important carbon-rich product that is generated from biomass sources through pyrolysis. Biochar (charcoal) can be both used directly as a potential source of solid biofuels and as soil amendments for barren lands. The aim of this study was investigate influence of pyrolysis temperature on the physicochemical properties and structure of biochar. The biochars were produced by pyrolysis of rapeseed (Brassica napus L.) using a fixed-bed reactor at different pyrolysis temperatures (400–700°C). The produced biochars were characterized by proximate and elemental analysis, Brunauer–Emmett–Teller (BET) surface area, particle size distributions, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy. The results showed that both chemical and surface properties of the biochars were significantly affected by the pyrolysis temperature. Aromatic hydrocarbons, hydroxyl and carbonyl compounds were the majority components of the biochar. The biochar obtained at 700°C had a high fixed carbon content (66.16%) as well as a high heating value, and therefore it could be used as solid fuel, precursor in the activated carbons manufacture (specific surface area until 25.38 m² g^?1), or to obtain category-A briquettes.     

Quantitative trait loci conferring grain mineral nutrient concentrations in durum wheat × wild emmer wheat RIL population

Mineral nutrient malnutrition, and particularly deficiency in zinc and iron, afflicts over 3 billion people worldwide. Wild emmer wheat, Triticum turgidum ssp. dicoccoides, genepool harbors a rich allelic repertoire for mineral nutrients in the grain. The genetic and physiological basis of grain protein, micronutrients (zinc, iron, copper and manganese) and macronutrients (calcium, magnesium, potassium, phosphorus and sulfur) concentration was studied in tetraploid wheat population of 152 recombinant inbred lines (RILs), derived from a cross between durum wheat (cv. Langdon) and wild emmer (accession G18-16). Wide genetic variation was found among the RILs for all grain minerals, with considerable transgressive effect. A total of 82 QTLs were mapped for 10 minerals with LOD score range of 3.2–16.7. Most QTLs were in favor of the wild allele (50 QTLs). Fourteen pairs of QTLs for the same trait were mapped to seemingly homoeologous positions, reflecting synteny between the A and B genomes. Significant positive correlation was found between grain protein concentration (GPC), Zn, Fe and Cu, which was supported by significant overlap between the respective QTLs, suggesting common physiological and/or genetic factors controlling the concentrations of these mineral nutrients. Few genomic regions (chromosomes 2A, 5A, 6B and 7A) were found to harbor clusters of QTLs for GPC and other nutrients. These identified QTLs may facilitate the use of wild alleles for improving grain nutritional quality of elite wheat cultivars, especially in terms of protein, Zn and Fe.     

Exogenous salicylate application affects the lead and copper accumulation characteristics of Lemna gibba L

Previous studies have shown that salicylates can change the ion permeability of root cells. Therefore the possible effects of exogenous salicylate application on lead (Pb) and copper (Cu) accumulation and its protective role against DNA damage due to metal exposure in Lemna gibba were studied. L. gibba was exposed to 5, 10, and 25 microM Pb and Cu for six days in the presence and absence of sodium salicylate (SA) (0.1, 0.5, and 1 mM). At all concentrations tested, SA application decreased Pb accumulation. On the other hand, application of 0.5 mM SA increased Cu accumulation. SA did not reduce DNA damage resulting from Pb and Cu toxicity. In summary, SA may be useful for reducing Pb accumulation, and application of SA at 0.5 mM may be useful for the phytoextraction of Cu.     

Pyrolysis of safflower (Charthamus tinctorius L.) seed press cake in a fixed-bed reactor: part 2. Structural characterization of pyrolysis bio-oils

Biomass in the form of agricultural residues is becoming popular among new renewable energy sources, especially given its wide potential and abundant usage. Pyrolysis is the most important process among the thermal conversion processes of biomass. In this study, the various characteristics of bio-oils acquired under different pyrolysis conditions from safflower seed press cake (SPC) were identified. The elemental analyses and calorific values of the bio-oils were determined, and then the chemical compositions of the bio-oils were investigated using chromatographic and spectroscopic techniques such as column chromatography, ¹H NMR, FTIR and GC. The fuel properties of the bio-oil such as kinematic viscosity, flash point, density, water content and ASTM distillation were also determined. Chemical compositions of bio-oils showed that some quantities of hydrocarbons were present, while oxygenated and polar fractions dominated. The bio-oils obtained from safflower seed press cake were presented as an environmentally friendly feedstock candidate for biofuels and chemicals.     

Mutations in C2orf37, Encoding a Nucleolar Protein, Cause Hypogonadism, Alopecia, Diabetes Mellitus, Mental Retardation, and Extrapyramidal Syndrome

Hypogonadism, alopecia, diabetes mellitus, mental retardation, and extrapyramidal syndrome (also referenced as Woodhouse-Sakati syndrome) is a rare autosomal recessive multisystemic disorder. We have identified a founder mutation consisting of a single base-pair deletion in C2orf37 in eight families of Saudi origin. Three other loss-of-function mutations were subsequently discovered in patients of different ethnicities. The gene encodes a nucleolar protein of unknown function, and the cellular phenotype observed in patient lymphoblasts implicates a role for the nucleolus in the pathogenesis of this disease. Our findings expand the list of human disorders linked to the nucleolus and further highlight the developmental and/or maintenance functions of this organelle.     

Clustering of halophytic species from Cyprus based on ionic contents

This paper presents the work conducted on the chemical constituents of some common and widely distributed halophyte taxa from Cyprus with the aim that these studies will help in the evaluation of halophytes for different economical purposes. The plant species of Crithmum maritimum L., Limbarda crithmoides (L.) Dumort, Atriplex portulacoides L., Salsola kali L., Atriplex halimus L., Limonium oleifolium Mill., L. meyeri (Boiss.) Kuntze; and Tetraena alba (L.f.) Beier & Thulin were collected in the middle of July. The shoot tissue and leaf samples were collected from the natural habitats and left for drying under air circulation followed by placing them in oven at 60 °C for 96 hours. The material was crushed using mortar and pestle and subjected to an analysis of macro- and micro-nutrients and biochemical compounds. K⁺/Na⁺ in the leaf tissues of the dicot species showed relatively high values depicting their behavior as Na+ includes but very low Cl- levels were recorded. Out of the species investigated here in 4 TFAA content was rather high. Values ranging from 0.5% to 1% dry weight were exhibited in one species. However, only 3 species showed very low TFAA values. Later may be due to low nitrogen availability in their environment. The phenetic analyses of eight halophyte species performed on the data matrix using Ntsys-pc program version 2.1 revealed that, cluster analysis of the overall results obtained here leads to 2 clusters. This discrimination appears to be as a result of their different abilities to accumulate either proline or glycine betaine.