Increased Hippocampal 5-Lipoxygenase mRNA Content in Melatonin-Deficient, Pinealectomized Rats

Abstract: Tryptophan hydroxylase, the initial and rate-limiting enzyme in the biosynthesis of the neurotransmitter serotonin, is activated by protein kinase A and calcium/calmodulin-dependent protein kinase. One important aspect of the regulation of any enzyme by a phosphorylation-dephosphorylation cascade, and one that is lacking for tryptophan hydroxylase, lies in the identification of its site of phosphorylation by protein kinases. Recombinant forms of brain tryptophan hydroxylase were expressed as glutathione S -transferase fusion proteins and exposed to protein kinase A. This protein kinase phosphorylates and activates full-length tryptophan hydroxylase. The inactive regulatory domain of the enzyme (corresponding to amino acids 1–98) was also phosphorylated by protein kinase A. The catalytic core of the hydroxylase (amino acids 99–444), which expresses high levels of enzyme activity, was neither phosphorylated nor activated by protein kinase A. Conversion of serine-58 to arginine resulted in the expression of a full-length tryptophan hydroxylase mutant that, although remaining catalytically active, was neither phosphorylated nor activated by protein kinase A. These results indicate that the activation of tryptophan hydroxylase by protein kinase A is mediated by the phosphorylation of serine-58 within the regulatory domain of the enzyme.     

RRW: repeated random walks on genome-scale protein networks for local cluster discovery

Background  

We propose an efficient and biologically sensitive algorithm based on repeated random walks (RRW) for discovering functional modules, e.g., complexes and pathways, within large-scale protein networks. Compared to existing cluster identification techniques, RRW implicitly makes use of network topology, edge weights, and long range interactions between proteins.     

Basic Fibroblast Growth Factor Attenuates Bisphosphonate-Induced Oxidative Injury but Decreases Zinc and Copper Levels in Oral Epithelium of Rat

Recent studies have reported oxidative damage due to bisphosphonate (BP) in various cancer tissues and neurons, although basic fibroblast growth factor (bFGF) induced antioxidant effects in the cells. The bFGF may modulate the BP-induced oxidative stress in oral epithelium of rats. This study was undertaken to explore possible beneficial antioxidant effects of bFGF on oxidative stress induced by BP in oral epithelium of rats. Twenty-eight rats were equally divided into four groups. The first group was used as control. The second, third and fourth groups intraperitoneally received BP (zoledronic acid), bFGF and BP + bFGF. At the end of 10 weeks, the rats were sacrificed, and oral epithelium samples were taken for analyses. In BP group, the lipid peroxidation levels were increased in the oral epithelium, while the activities of glutathione peroxidase (GSH-Px) and the concentrations of total antioxidant status (TAS) were decreased. In rats treated with bFGF, lipid peroxidation levels decreased, and the activities of GSH-Px and concentrations of TAS improved in the oral epithelium. However, zinc and copper levels were decreased in the oral epithelium by BP and bFGF treatments. Concentrations of vitamin E and reduced glutathione in the samples did not change in the groups. In conclusion, treatment with bFGF modulated the antioxidant redox system and reduced the oral epithelium oxidative stress induced by BP. However, zinc and copper levels were decreased by BP and bFGF treatments.     

Syntheses,characterization, antimicrobial and cytotoxic activities of pyridine-2,5-dicarboxylate complexes with 1,10-phenanthroline

In this study, four mononuclear M(II)-pyridine-2,5-dicarboxylate (M = Co(II), Ni(II), Cu(II) and Zn(II) complexes with pyridine-2,5-dicarboxylic acid or isocinchomeronic acid, 1,10-phenanthroline (phen), [Co(Hpydc)₂(phen)]·H₂O (1), [Ni(pydc)(phen)₂]·6.5H₂O (2) [Cu(pydc)(phen)(H₂O)₂] (3) and [Zn(pydc)(phen)(H₂O)₂]·H₂O (4) have been synthesized. Elemental, thermal and mass analyses, molar conductance, magnetic susceptibilities, IR and UV/vis spectroscopic studies have been performed to characterize the complexes. Subsequently, these ligands and complexes were tested for antimicrobial activity by disc diffusion method on Gram positive, negative bacteria and yeast. In addition, cytotoxic activity tests were performed on rat glioma (C6) cells by MTT viability assay for 24 and 48 h. Antimicrobial activity results demonstrated that when compared to the standard antibiotics, phen displayed the most effective antimicrobial effect. The effect of synthesized complexes was close to phen or less. Cytotoxic activity results showed that IC₅₀ value of phen was determined as 31 μM for 48 h. (1) and (2) compared to the alone ligand had less toxic activity. IC₅₀ values of (3) for 24 and 48 h treatments were 2.5 and 0.6 μM, respectively. IC₅₀ value of (4) for 48 h was 15 μM. In conclusion, phen, (3) and (4) may be useful as antibacterial and antiproliferative agents in the future.     

The impact of the marine sewage outfalls on the sediment quality: The Black Sea and the Marmara case

Marine sewage outfalls are the cheapest method of disposal for municipalities with restricted funds, despite their negative effects on marine ecosystems. This study was conducted on the marine sewage outfalls of the Turkish cities Rize (Black Sea) and Yalova (Sea of Marmara). Heavy metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) were investigated in the sediments for determine pollution degree. Two of Yalova stations were classified as having high contamination levels (1034.436 and 1476.483 ng/g, respectively) and all the other stations suffered moderate pollution in terms of ∑₁₆PAHs. ∑DTTs in sediments above probable effect levels (PELs), were observed both stations Yalova and Rize. The highest metal concentrations in the sediments from the eight stations ranged from 4.97 to 29.65 mg/kg for Ni; 7.57–44.14 mg/kg for Cr; 9.84–42.76 mg/kg for Cu; and 48.08–103.77 mg/kg for Zn. In sum, examination of pollutant sources provides clear evidence of an anthropogenic effect on the discharge environments.     

Clinical-grade,large-scale,feeder-free expansion of highly active human natural killer cells for adoptive immunotherapy using an automated bioreactor

Background aimsNatural killer (NK) cell-based adoptive immunotherapy is a promising approach for the treatment of cancer. Ex vivo expansion and activation of NK cells under good manufacturing practice (GMP) conditions are crucial for facilitating large clinical trials. The goal of this study was to optimize a large-scale, feeder-free, closed system for efficient NK cell expansion.MethodsPeripheral blood mononuclear cells (PBMCs) from healthy donors and myeloma patients were cultured for 21 days using flasks, cell culture bags and bioreactors. Final products from different expansions were evaluated comparatively for phenotype and functionality.ResultsSignificant NK cell expansions were obtained in all systems. The bioreactor yielded a final product rich in NK cells (mean 38%) ensuring that a clinically relevant cell dose was reached (mean 9.8 × 10⁹ NK cells). Moreover, we observed that NK cells expanded in the bioreactor displayed significantly higher cytotoxic capacity. It was possible to attribute this partially to a higher expression level of NKp44 compared with NK cells expanded in flasks.ConclusionsThese results demonstrate that large amounts of highly active NK cells for adoptive immunotherapy can be produced in a closed, automated, large-scale bioreactor under feeder-free current GMP conditions, facilitating clinical trials for the use of these cells.     

Pharmacological and structural characterization of long-sarafotoxins, a new family of endothelin-like peptides: Role of the C-terminus extension

Long-sarafotoxins (l-SRTXs) have recently been identified in both the venom of Atractaspis microlepidota and that of Atractaspis irregularis. They are characterized by different C-terminus extensions that follow the invariant Trp21, which plays a crucial role in endothelin-receptor binding. We initially determined the toxicity and three-dimensional structures of two chemically synthesized l-SRTXs that have different C-terminus extensions, namely SRTX-m (24 aa, including extension "D-E-P") and SRTX-i3 (25 aa, including extension "V-N-R-N"). Both peptides were shown to be highly toxic in mice and displayed the cysteine-stabilized α-helical motif that characterizes endothelins and short-SRTXs, to which a longer C-terminus with variable flexibility is added. To discern the functional and pharmacological consequences of the supplementary amino acids, different chimerical as well as truncated forms of SRTX were designed and synthesized. Thus, we either removed the extra-C-terminal residues of SRTX-m or i3, or grafted the latter onto the C-terminal extremity of a short-SRTX (s-SRTX) (ie. SRTX-b). Our competitive binding assays where SRTXs competed for iodinated endothelin-1 binding to cloned ET(A) and ET(B) receptor subtypes over-expressed in CHO cells, revealed the essential role of the C-terminus extensions for ET-receptor recognition. Indeed, l-SRTXs displayed an affinity three to four orders of magnitude lower as compared to SRTX-b for the two receptor subtypes. Moreover, grafting the C-terminus extension to SRTX-b induced a drastic decrease in affinity, while its removal (truncated l-SRTXs) yielded an affinity for ET-receptors similar to that of s-SRTXs. Furthermore, we established by intracellular Ca(2+) measurements that l-SRTXs, as well as s-SRTXs, display agonistic activities. We thus confirmed in these functional assays the major difference in potency for these two SRTX families as well as the crucial role of the C-terminus extension in their various pharmacological profiles. Finally, one of the chimeric toxin synthesized in this study appears to be one of the most potent and selective ligand of the ET(B) receptor known to date.     

The effects of different adhesive agents on the shear bond strength of a self-adhesive resin cement

Purpose: To compare the clinical success of a self-adhesive resin cement used in combination with different adhesive bonding systems with that of a conventional dual-cure resin cement. Methods: The study was performed with 136 freshly extracted molars embedded in acrylic resin blocks and 136 IPS e.max Press discs. Teeth and discs were randomly divided into four equal groups and cemented together using either RelyX ARC (ARC), RelyX Unicem (Unicem), RelyX Unicem+Adper-Prompt L-pop (L-pop), or RelyX and Unicem+Total-etch (Total-etch). Shear bond strength measurements were obtained before and after thermocycling. Following bond testing, the surfaces of one sample per subgroup (thermocycled and non-thermocycled), were assessed using scanning electron microscopy (SEM). Results: Among the non-thermocylced subgroups, ARC exhibited the highest bond strength values, followed by Total Etch, Unicem and L-pop. ARC also exhibited the highest bond strength values among the thermocycled subgroups, followed by Unicem, Total-etch, and L-pop. SEM analysis clearly revealed the negative effects of thermo-cycling on the mechanical properties of adhesive agents. Conclusions: RelyX Unicem may be preferable in many cases because of its simplified application and reduced technique-sensitivity.