Adsorption and immobilisation of human insulin on graphene monoxide,silicon carbide and boron nitride nanosheets investigated by molecular dynamics simulation

The adsorption and immobilisation of human insulin onto the bio-compatible nanosheets including graphene monoxide, silicon carbide and boron nitride nanosheets were studied by molecular dynamics simulation at the temperature of 310 K. After equilibration, heating and 100 ns production molecular dynamic runs, it was found that the insulin was adsorbed and immobilised onto the considered surfaces in a native folded state. The structural parameters, including root-mean-square deviation and fluctuation, surface accessible solvent area, radius of gyration (R_g) and the distance between the centre of the mass of immobilised protein and the surface of the considered nanosheets, were measured, analysed and discussed. The energetics of the studied systems such as the interaction energy between protein and nanosheet was also measured and addressed. The discussions were centred on the structural and energetic parameters of the protein and nanosheets, including charge density, hydrophobicity, hydrophilicity and residue polarity. The results also showed that the active site of C-termini of chain B played an important role in the adsorption process and this could be helpful in the protection of insulin in its smart delivery and release applications.     

Differential physiological and biochemical responses of Quercus infectoria and Q. libani to drought and charcoal disease

The vast oak-dominated forests of the Zagros Mountains in southwestern Iran currently undergo large-scale dieback driven by a combination of drought and increasing incidence of charcoal disease caused by the fungal pathogens Biscogniauxia mediterranea and Obolarina persica. Here, we explore the interactive effects between drought and charcoal disease agents on the physiology and biochemistry of Quercus infectoria and Quercus libani seedlings. The combination of pathogen attack and water limitation hampered plant development, especially in Q. libani seedlings, negatively affecting growth, biomass production, photosynthetic efficiency, and leaf water potential. An increase in markers of oxidative damage together with the upregulation of the antioxidant defense revealed that drought stress and pathogen infection led to pro-oxidative conditions in both oak species, especially in Q. libani, where larger changes in malondialdehyde and hydrogen peroxide occurred. The upregulation of the antioxidant system was more prominent in Q. infectoria than in Q. libani, resulting in enhanced enzyme activity and accumulation of non-enzymatic antioxidants. Fungal infection stimulated the activity of chitinase, phenylalanine ammonia lyase and β-1,3-glucanase in Q. infectoria leaves and this response became more pronounced under water shortage. Our study highlights that drought stress greatly intensifies the effects of the charcoal disease. Moreover, our findings imply superior stress resistance of Q. infectoria conferred by a highly efficient antioxidant system, strong osmotic adjustment (through proline), and increases in resistance enzymes and secondary metabolites (phenols and flavonoids). Future investigations should focus on adult trees in their natural habitat including interactions with soil factors and other pathogens like nematodes, bacteria and other fungi. Because the present research was conducted on oak seedlings, the findings can be considered by forest nursery managers.     

N-acetyltransferase polymorphism among northern Sudanese

Interindividual and interethnic differences in allele frequencies of N-acetyltransferase (NAT2) single nucleotide polymorphisms (SNPs) are responsible for phenotypic variability of adverse drug reactions and susceptibility to cancer. We genotyped the seven NAT2 common SNPs in 127 randomly selected unrelated northern Sudanese subjects using allele-specific and RFLP polymerase chain reaction (PCR) based methods. Molecular genotyping was enough to designate alleles for 41 individuals unambiguously, whereas 63 individuals' alleles were inferred from haplotypes previously described. In the remaining 23 individuals, however, the phase of the SNPs could not be decided because of multiple SNP heterozygotes. Using computational methods in the HAP and Phase programs, we confirmed the inferred alleles of the 62 individuals and predicted the remaining 23 ambiguous alleles. Twelve NAT2 alleles were identified. Four alleles coded for rapid acetylators (18%), and eight alleles coded for slow acetylators (82%). Two genotypes coded for rapid acetylation (3.9%), 10 for intermediate acetylation (27.6%), and 13 for slow acetylation (68.5%). The G191A African SNP and the G857A predominantly Asian SNP were each detected at a low frequency of 3.1%. The combination of molecular and computational analysis was useful in resolving ambiguous genotypes of NAT2 in multiple SNP heterozygotes. Among the northern Sudanese the SNPs associated with slow acetylation are more prevalent than in Caucasians and Asians. This and other African studies are suggestive of an African origin for NAT2-associated polymorphism.     

The relation of omentin gene expression and glucose homeostasis of visceral and subcutaneous adipose tissues in non-diabetic adults

Molecular Biology Reports - Adipose tissue (AT) is a passive reservoir for energy storage and an active endocrine organ responsible for synthesizing bioactive molecules called...     

Gene expression analysis of intestinal IL-8, IL-17 A and IL-10 in patients with celiac and inflammatory bowel diseases

Molecular Biology Reports - Celiac disease (CeD) and inflammatory bowel disease (IBD) are accompanied by impaired immune responses. To study the immune regulation of these diseases, we evaluated...     

Contamination of breast milk with lead,mercury, arsenic,and cadmium in Iran: a systematic review and meta-analysis

BioMetals - Breast milk is a complete food for the development of the newborn, but it can also be an important route for environmental pollutants transmission to the infants. This study was aimed...     

Targeting Apoptosis and Multiple Signaling Pathways with Icariside II in Cancer Cells

Cancer is the second leading cause of deaths worldwide. Despite concerted efforts to improve the current therapies, the prognosis of cancer remains dismal. Highly selective or specific blocking of only one of the signaling pathways has been associated with limited or sporadic responses. Using targeted agents to inhibit multiple signaling pathways has emerged as a new paradigm for anticancer treatment. Icariside II, a flavonol glycoside, is one of the major components of Traditional Chinese Medicine Herba epimedii and possesses multiple biological and pharmacological properties including anti-inflammatory, anti-osteoporosis, anti-oxidant, anti-aging, and anticancer activities. Recently, the anticancer activity of Icariside II has been extensively investigated. Here, in this review, our aim is to give our perspective on the current status of Icariside II, and discuss its natural sources, anticancer activity, molecular targets and the mechanisms of action with specific emphasis on apoptosis pathways which may help the further design and conduct of preclinical and clinical trials.Icariside II has been found to induce apoptosis in various human cancer cell lines of different origin by targeting multiple signaling pathways including STAT3, PI3K/AKT, MAPK/ERK, COX-2/PGE2 and β-Catenin which are frequently deregulated in cancers, suggesting that this collective activity rather than just a single effect may play an important role in developing Icariside II into a potential lead compound for anticancer therapy. This review suggests that Icariside II provides a novel opportunity for treatment of cancers, but additional investigations and clinical trials are still required to fully understand the mechanism of therapeutic effects to further validate it in anti-tumor therapy.     

In vivo analysis of local wall stiffness at the shoot apical meristem in Arabidopsis using atomic force microscopy

Whereas the morphogenesis of developing organisms is relatively well understood at the molecular level, the contribution of the mechanical properties of the cells to shape changes remains largely unknown, mainly because of the lack of quantified biophysical parameters at cellular or subcellular resolution. Here we designed an atomic force microscopy approach to investigate the elastic modulus of the outer cell wall in living shoot apical meristems (SAMs). SAMs are highly organized structures that contain the plant stem cells, and generate all of the aerial organs of the plant. Building on modeling and experimental data, we designed a protocol that is able to measure very local properties, i.e. within 40-100 nm deep into the wall of living meristematic cells. We identified three levels of complexity at the meristem surface, with significant heterogeneity in stiffness at regional, cellular and even subcellular levels. Strikingly, we found that the outer cell wall was much stiffer at the tip of the meristem (5 ± 2 MPa on average), covering the stem cell pool, than on the flanks of the meristem (1.5 ± 0.7 MPa on average). Altogether, these results demonstrate the existence of a multiscale spatialization of the mechanical properties of the meristem surface, in addition to the previously established molecular and cytological zonation of the SAM, correlating with regional growth rate distribution.     

Electromembrane extraction of trace amounts of naltrexone and nalmefene from untreated biological fluids

Nalmefene and naltrexone are used to block the effects of narcotics and alcohol. In the present work, for the first time a microextraction technique was presented to reduce matrix interferences and improve detection limits of the drugs in urine and plasma samples. Electromembrane extraction (EME) followed by high performance liquid chromatography (HPLC) coupled with ultraviolet (UV) detection was optimized and validated for quantification of nalmefene and naltrexone from biological fluids. The membrane consists 85% of 2-nitrophenyl octyl ether (NPOE) and 15% di-(2-ethylhexyl) phosphate (DEHP) immobilized in the pores of a hollow fiber. A 100 V electrical field was applied to make the analytes migrate from sample solution with pH 2.0, through the supported liquid membrane (SLM) into an acidic acceptor solution with pH 1.0 which was located inside the lumen of hollow fiber. Extraction recoveries in the range of 54% and 75% were obtained in different biological matrices which resulted in preconcentration factors in the range of 109-149 and satisfactory repeatability (2.0相似文献