Effect of the Heavy Metals on Developmental Stages of Ovule,Pollen, and Root Proteins in <Emphasis Type="Italic">Reseda lutea</Emphasis> L. (Resedaceae)

Heavy metals are some of the most important environmental pollutants. Excessive amounts of heavy metals adversely affect plant growth and development. Also, the presence of elevated levels of heavy metal ions triggers a wide range of cellular responses including changes in gene expression and synthesis of metal-detoxifying peptides. The overall objective of this research was to elucidate some microscopic effects of heavy metals on the formation, development, and structure of pollen, ovule, and embryo and also root proteins in Reseda lutea L. For this purpose, the vicinity of Ahangaran lead–zinc mine (Hamedan, Iran) was chosen as a polluted area where amount of some heavy metals was several times higher than the natural soils. Flowers and young buds were collected from non-polluted and polluted plants, fixed in FAA₇₀, and studied during developmental stages by light microscopy. The results showed that heavy metals can cause some abnormalities during the pollen and ovule developmental process. The number of pollen grains was decreased, and their shape was changed. Increasing in thickness of the callosic wall and stabilizing of tapetum layer were observed in polluted plants. Asymmetrical formation of ovular integuments, degradation of egg apparatus, irregular formation of embryo sac, considerable vacuolation of embryonic cells, and degeneration of embryo in the late stage of heart-shaped embryo are the results of heavy metal pollution. For protein studies, young roots were harvested from plants exposed to pollution and non-exposed to pollution at the same time. Root proteins were extracted and studied by electrophoresis. The results revealed that some new proteins were synthesized in polluted samples that probably elevate plant tolerance to heavy metals.     

Chitooligosaccharide-mediated neuroprotection is associated with modulation of Hsps expression and reduction of MAPK phosphorylation

There is mounting evidence implicating the role of oxidative stress induced by reactive oxygen species (ROS) in neurodegenerative disease, including Alzheimer's disease. In this study we aimed to investigate the possible protective effect of chitooligosaccharide (COS), an antioxidant oligosaccharide, on hydrogen peroxide induced apoptosis in NGF-differentitated rat pheochromocytoma (PC12) cells. COS treatment reversed the decrease of cell viability induced by H(2)O(2) and this was associated with diminished intracellular ROS and decreased level of cytosolic Ca(2+). Additionally, COS contributed to up-regulation of Bcl-2, down regulation of Bax protein and reduction of cleaved Caspase-3 protein. COS treatment stabilized Nrf2 in nucleus and increased the Hsp70 level within cell while down-regulated Hsp90 expression. Moreover, COS could inhibit the phosphorylation of different mitogen activated protein kinases (MAPKs), whose aberrant phosphorylation has been implicated in AD. Our findings suggest that heat shock response and MAPK cascades are both involved in cell survival, and by concomitantly regulating both pathways, COS can be a promising agent in treating neurodegenerative diseases.     

Efficient media for high menaquinone-7 production: response surface methodology approach

The aim of this study was to assess the effect of nutrients on the production of menaquinone-7 and determine the optimum conditions to achieve a high concentration of this product. Bacillus subtilis natto was fermented at 40°C for a period of six days. Design of experiments was used for screening the most effective nutrients, and central composite face design was employed for the optimization. The optimum media consisted of 5% (w/v) yeast extract; 18.9% (w/v) soy peptone; 5% (w/v) glycerol and 0.06% (w/v) K(2)HPO(4). The pH, bacterial growth, concentrations of amino acids, glycerol and menaquinone-7 were measured at the optimum fermentation media each day. Total free amino acids concentration increased 1.7-fold during the fermentation. Lysine and glutamic acid were the most abundant whereas arginine, asparagine and serine were the limiting amino acids at the end of fermentation period. The menaquinone-7 concentration approached 86% of the final value in the third day of fermentation, where the bacteria growth was at exponential phase. At this condition the concentration of glycerol as carbon source and asparagine, serine and arginine as the amino acid sources were dramatically diminished in the fermentation media. The optimum menaquinone-7 concentration was in good agreement with the predicted value by the model (96% validity). The maximum menaquinone-7 concentration of 62.32 ± 0.34 mg/L was achieved after six days of fermentation; this value is the highest concentration reported in the literature.     

Modeling the interaction between anti-cancer drug penicillamine and pristine and functionalized carbon nanotubes for medical applications: density functional theory investigation and a molecular dynamics simulation

Abstract

The present study focuses on the prediction and investigation of binding properties of penicillamine with pure (5,5) single-walled carbon nanotube (SWCNT) and functionalized SWCNT (f-SWCNT) through the B3LYP and M06-2X functionals using the 6-31G** basis set. The electronic and structural properties, adsorption energy and frontier molecular orbitals of various configurations are examined. Our theoretical results indicated that the interaction of the nanotubes with penicillamine molecule is weak so that the drug adsorption process is typically physisorption. Also, results of theoretical calculations show that the adsorption of the drug molecule on f-SWCNT is stronger with shorter intermolecular distances in comparison to pure SWCNT. The natural bond orbital (NBO) analysis of studied systems demonstrates that the charge is transferred from penicillamine molecule to the nanotubes. Furthermore, molecular dynamics (MD) simulation is employed to evaluate the dynamic and diffusion behavior of drug molecule on SWCNT and f-SWCNT. Energy results show that drug molecule spontaneously moves toward the carriers, and the van der Waals energy contributions in drug adsorption are more than electrostatic interaction. The obtained results from MD simulation confirm that the functionalization of SWCNT leads to increase in the solubility of the carrier in aqueous solution.

Communicated by Ramaswamy H. Sarma     

Brown Adipose Tissue Quantification in Human Neonates Using Water-Fat Separated MRI

There is a major resurgence of interest in brown adipose tissue (BAT) biology, particularly regarding its determinants and consequences in newborns and infants. Reliable methods for non-invasive BAT measurement in human infants have yet to be demonstrated. The current study first validates methods for quantitative BAT imaging of rodents post mortem followed by BAT excision and re-imaging of excised tissues. Identical methods are then employed in a cohort of in vivo infants to establish the reliability of these measures and provide normative statistics for BAT depot volume and fat fraction. Using multi-echo water-fat MRI, fat- and water-based images of rodents and neonates were acquired and ratios of fat to the combined signal from fat and water (fat signal fraction) were calculated. Neonatal scans (n = 22) were acquired during natural sleep to quantify BAT and WAT deposits for depot volume and fat fraction. Acquisition repeatability was assessed based on multiple scans from the same neonate. Intra- and inter-rater measures of reliability in regional BAT depot volume and fat fraction quantification were determined based on multiple segmentations by two raters. Rodent BAT was characterized as having significantly higher water content than WAT in both in situ as well as ex vivo imaging assessments. Human neonate deposits indicative of bilateral BAT in spinal, supraclavicular and axillary regions were observed. Pairwise, WAT fat fraction was significantly greater than BAT fat fraction throughout the sample (Δ_WAT-BAT = 38%, p<10⁻⁴). Repeated scans demonstrated a high voxelwise correlation for fat fraction (R_all = 0.99). BAT depot volume and fat fraction measurements showed high intra-rater (ICC_BAT,VOL = 0.93, ICC_BAT,FF = 0.93) and inter-rater reliability (ICC_BAT,VOL = 0.86, ICC_BAT,FF = 0.93). This study demonstrates the reliability of using multi-echo water-fat MRI in human neonates for quantification throughout the torso of BAT depot volume and fat fraction measurements.     

Fumigant toxicity of Laurus nobilis and Myrtus communis essential oils on larvae and adults of the Red flour beetle,Tribolium castaneum Herbst (Col.: Tenebrionidae)

Considering the invasion to food commodities by insects and harmful effect of chemical pesticides, essential oils are among the best known substances tested against stored product pests. These compounds may act as fumigants, contact insecticides, repellents or anti-feedants. In present study, fumigant toxicity of essential oils from Laurus nobilis L. and Myrtus communis L. was assessed on larvae and adults of Tribolium castaneum Herbst at 27?±?2?°C, 60?±?5% RH in darkness. Each essential oil was tested in five concentrations with three replicates. The LC₅₀ values of L. nobilis and M. communis against adults of beetle were calculated 243.78 and 56.11?μl/l and LC₉₅ values for them were 685.85 and 144.01?μl/l, respectively. For the larvae of T. castaneum, the LC₅₀ values for L. nobilis and M. communis were 211.64 and 69.63 and LC₉₅ values were 656.84 and 183.65?μl/l, respectively. Results showed that these essential oils may have potential as botanical control agents against larvae and adults of T. castaneum.     

Enhancement of the anti-melanoma response of Hu14.18K322A by αCD40 + CpG

Targeted monoclonal antibodies (mAb) can be used therapeutically for tumors with identifiable antigens such as disialoganglioside GD2, expressed on neuroblastoma and melanoma tumors. Anti-GD2 mAbs (αGD2) can provide clinical benefit in patients with neuroblastoma. An important mechanism of mAb therapy is antibody-dependent cellular cytotoxicity (ADCC). Combinatorial therapeutic strategies can dramatically increase the anti-tumor response elicited by mAbs. We combined a novel αGD2 mAb, hu14.18K322A, with an immunostimulatory regimen of agonist CD40 mAb and class B CpG-ODN 1826 (CpG). Combination immunotherapy was more effective than the single therapeutic components in a syngeneic model of GD2-expressing B16 melanoma with minimal tumor burden. NK cell depletion in B6 mice showed that NK cells were required for the anti-tumor effect; however, anti-tumor responses were also observed in tumor-bearing SCID/beige mice. Thus, NK cell cytotoxicity did not appear to be essential. Peritoneal macrophages from anti-CD40 + CpG-treated mice inhibited tumor cells in vitro in an hu14.18K322A antibody-dependent manner. These data highlight the importance of myeloid cells as potential effectors in immunotherapy regimens utilizing tumor-specific mAb and suggest that further studies are needed to investigate the therapeutic potential of activated myeloid cells and their interaction with NK cells.