Melatonin and pancreatic cancer: Current knowledge and future perspectives

Pancreatic cancer has a high mortality rate due to the absence of early symptoms and subsequent late diagnosis; additionally, pancreatic cancer has a high resistance to radio- and chemotherapy. Multiple inflammatory pathways are involved in the pathophysiology of pancreatic cancer. Melatonin an indoleamine produced in the pineal gland mediated and receptor-independent action is the pancreas and other where has both receptors. Melatonin is a potent antioxidant and tissue protector against inflammation and oxidative stress. In vivo and in vitro studies have shown that melatonin supplementation is an appropriate therapeutic approach for pancreatic cancer. Melatonin may be an effective apoptosis inducer in cancer cells through regulation of a large number of molecular pathways including oxidative stress, heat shock proteins, and vascular endothelial growth factor. Limited clinical studies, however, have evaluated the role of melatonin in pancreatic cancer. This review summarizes what is known regarding the effects of melatonin on pancreatic cancer and the mechanisms involved.     

Introduction of Fluorine Into the C8 Position of Purine Nucleosides

Abstract

We have synthesized 2-amino-6,8-difluoro-9-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)purine (3) from 2-amino-6,8-dichloro-9-(2,3,5-tri-O-acetyl-ß-D-ribofuranosyl)purine (1) in a two-step procedure. The reaction of 3 with anhydrous ammonia in dry 1,2-dimethoxyethane gave 2,8-diamino-6-fluoro-9-(2,3,5-tri-O-acetyl-ß-D-ribofuranosyl)purine (4) in 64.1% yield. Compound 4 was deaminated with t-butylnitrite in tetrahydrofuran to give 2-amino-6-fluoro-9-(2,3,5-tri-O-acetyl-ß-D-ribofuranosyl)purine (6). The ¹H, ¹⁹F, and ¹³C NMR spectral data were determined and evaluated for each of the compounds.     

The Effect of Leptin on Sex Hormones and Antioxidant Enzyme Levels in Obese and Normal Male Rats

International Journal of Peptide Research and Therapeutics - The correlation between leptin, nutritional status and reproductive performance is known but its effect on male obese is not fully...     

Enhancing compost quality by using whey-grown biosurfactant-producing bacteria as inocula

Wild screening of bacterial strains from compost materials was performed. Several biosurfactant-producer strains were isolated and then cultured in whey as a low-cost medium for biosurfactant production. Two strains, identified as Bacillus sp. and Streptomyces sp., were the best biosurfactant producers and were selected for determination of compost quality enhancing. The effect of cell biomass, cell-free supernatant, and a consortium of these two strains on compost quality were determined and specific parameters of compost were analyzed. The results showed that using these bacteria (or supernatants) in compost processing have slight stimulatory effect on bacterial population (8.08 log₁₀ CFU/g), surface tension reduction (to 42.6 mN/m at 24 h), and heavy metal bioremediation (>50 % in most treatments), speeding up the decomposition rate of organic matter (42.3 % OM at the end of experiment), accelerating the stabilization process by reduction of NH ₄ ⁺ to NO ₃ ^? ratio (reduced from 0.2 to 0.026), decreasing the biotoxicity (tested by seed germination and root length of germinated seed), and also reduction of pathogens (reduced from 2100 to 120 MPN/g in fecal coliform).     

Density functional theory study of epoxy polymer chains adsorbing onto single-walled carbon nanotubes: electronic and mechanical properties

We performed first principles calculations based on density functional theory (DFT) to investigate the effect of epoxy monomer content on the electronic and mechanical properties of single-walled carbon nanotubes (SWCNTs). Our calculation results reveal that interfacial interaction increases with increasing numbers of epoxy monomers on the surface of SWCNTs. Furthermore, density of states (DOS) results showed no orbital hybridization between the epoxy monomers and nanotubes. Mulliken charge analysis shows that the epoxy polymer carries a positive charge that is directly proportional to the number of monomers. The Young’s modulus of the nanotubes was also studied as a function of monomer content. It was found that, with increasing number of monomers on the nanotubes, the Young’s modulus first decreases and then approaches a constant value. The results of a SWCNT pullout simulation suggest that the interfacial shear stress of the epoxy/SWCNT complex is approximately 68 MPa. These results agreed well with experimental results, thus proving that the simulation methods used in this study are viable.     

8-Diazoguanosine, 2,8-Diaminoadenosine and Other Purine Nucleosides Derived from Guanosine

Abstract

Diazotization of 8-aminoguanosine gave 8-diazoguanosine (2) which is stable in neutral and basic media, but decomposes to D-ribose and 8-diazoguanine in acidic conditions. 2-Amino-6,8-dichloro-9-(2,3,5-tri-0-acetyl-β-D-ribo-furanosyl)purine (5) was employed to synthesize 9-β-D-ribofuranosyl-2,6,8-triaminopurine (8) and a number of N6-alkyl-2-amino-8-chloro-9-β-D-ribofuranosylpurines.     

A New Proposal for Highly Sensitive Refractive Index Sensor Using Vertically Coupled Plasmonic Elliptic-Disk up Elliptic-Ring Nanoparticles

Plasmonics - In this research work, a novel highly sensitive refractive index sensor using Au and Ag elliptic-shaped nanoparticles are proposed. The main idea of this work is using an original...     

Trophic flexibility of Eurasian otter (Lutra lutra) in Anzali Wetland,Iran, assessed by fecal and stable isotope analysis

Aquatic Ecology - Information on the feeding habits of species is essential to develop appropriate conservation actions. This study aimed to assess spatial and temporal variation in the diet of the...