Effect of intravenous nitroglycerin therapy on erythrocyte antioxidant enzymes

Intravenous nitroglycerin (GTN) has been used as an anti-ischemic agent for the therapy of unstable and post-infarction angina. Nitric oxide (NO) and S-nitrosothiols constitute the biologically active species formed via nitroglycerin bioactivation. Increased levels of reactive oxygen species can diminish the therapeutic action of organic nitrates by scavenging donated NO and oxidizing tissue thiols important in nitrate biotransformation. Studies reported here show that the red cell activity of antioxidant enzymes, catalase and glutathione peroxidase, are significantly decreased after intravenous nitroglycerin treatment. Catalase activity (739.6 +/- 92.3 k/gHb) decreased to 440.1 +/- 111.9 and 459.8 +/- 130.7 k/gHb after 1 and 24 hr GTN infusion, respectively. Similarly, glutathione peroxidase activity (5.8 +/- 1.8 U/gHb) decreased to 3.2 +/- 1.7 and 3.8 +/- 1.1 U/g Hb after 1 and 24 hr GTN infusion, respectively. The reported decrease in antioxidant enzyme activities can lead to an oxidant milieu and contribute to the generation of nitrate tolerance.     

A facile and efficient method of enzyme immobilization on silica particles via Michael acceptor film coatings: immobilized catalase in a plug flow reactor

A novel method was developed for facile immobilization of enzymes on silica surfaces. Herein, we describe a single-step strategy for generating of reactive double bonds capable of Michael addition on the surfaces of silica particles. This method was based on reactive thin film generation on the surfaces by heating of impregnated self-curable polymer, alpha-morpholine substituted poly(vinyl methyl ketone) p(VMK). The generated double bonds were demonstrated to be an efficient way for rapid incorporation of enzymes via Michael addition. Catalase was used as model enzyme in order to test the effect of immobilization methodology by the reactive film surface through Michael addition reaction. Finally, a plug flow type immobilized enzyme reactor was employed to estimate decomposition rate of hydrogen peroxide. The highly stable enzyme reactor could operate continuously for 120 h at 30 °C with only a loss of about 36 % of its initial activity.     

An assessment of initial body size in loggerhead sea turtle (Caretta caretta) hatchlings in Turkey

Eggs, hatchlings, and adult loggerhead turtles, and incubation durations of clutches, were measured on three Turkish beaches (Dalyan, Fethiye and G?ksu Delta), and some physical features of nests were compared. These features were not statistically different among the beaches, except for nest depth and distance to the high water mark. There was a positive relationship between hatchling mass and egg size. The carapace length of hatchlings was correlated with both egg diameter and incubation duration. The duration of asynchronous emergence of hatchlings on Fethiye beach was slightly longer than on the other two beaches, and the size of hatchlings decreased as asynchronous emergence proceeded. Of the hatchlings that emerged first, those that died were significantly smaller in SCL and mass than those that lived. These results suggest that smaller hatchlings may not be vigorous enough to emerge earlier from nests, and that they may be less fit.     

Immobilization and stabilization of papain on poly(hydroxyethyl methacrylate-ethylenglycol dimethacrylate) beads grafted with epoxy functional polymer chains via surface-initiated-atom transfer radical polymerization (SI-ATRP)

Poly(hydroxyethyl methacrylate–ethylen glycol dimethacrylate), p(HEMA–EGDMA), beads were prepared by suspension polymerization, and were decorated with fibrous poly(glycidyl methacrylate), p(GMA), via surface initiated-atom transfer radical polymerization (SI-ATRP). The functional epoxy groups of the beads were used for covalent immobilization of papain. The average amount of immobilized enzyme was 18.7 mg/g beads. The immobilized enzyme was characterized by temperature, pH, operational and storage stability experiments. The maximum velocity of the free and immobilized enzymes (V_max) and Michaelis–Menten constant (K_m) values were determined as 10.7 and 8.3 U/mg proteins and 274 and 465 μM, respectively. The immobilized papain was operated in a batch reactor, and it was very effective for hydrolysis of different proteins (i.e., casein and cytochrom c).     

Beneficial Effects of Ibuprofen on Pentylenetetrazol-induced Convulsion

Neurochemical Research - Ibuprofen is a non-steroidal anti-inflammatory drug (NSAID) that is commonly used as an anti-inflammatory, anti-pyretic, and analgesic. Although some studies have focused...     

Synthesis,Antiproliferative and Cytotoxic Activities,DNA Binding Features and Molecular Docking Study of Novel Enamine Derivatives

Novel enamine derivatives were synthesized from the reaction of lactone and chalcones and their antiproliferative and cytotoxic activities against six cancer cell lines (e. g., HeLa, HT29, A549, MCF7, PC3 and Hep3B) and one normal cell lines (e. g., FL) were investigated along with their mode of interactions with CT‐DNA. Most of the enamine derivatives with IC₅₀ values of 86–168 μM demonstrated much stronger antiproliferative activity than the starting molecules against the cancer cells. While, among the enamine derivatives, four compounds displayed higher cytotoxic potency than the control drugs (5‐fluorouracil and cisplatin) against the Hep3B cell lines, these compounds did not exhibit any significant toxicity against normal cells, FL. The UV/VIS spectral data suggest that eight compounds cause hypochromism with a slight bathochromic shift (～6 nm), indicating that they bind to the DNA by way of an intercalative or minor groove binding mode. The binding constants of the compounds are in the range of 0.1×103 M^?1–2.3×104 M^?1. The antiproliferative activity of studied enamine derivatives could possibly be due to their DNA binding as well as their cytotoxic properties. In addition to these assays, the chalcones and enamine derivatives were investigated by molecular docking to calculate the synergistic effect of antiproliferative activities against six human cancer cell lines.     

Benzimidazolium-based novel silver N-heterocyclic carbene complexes: synthesis,characterisation and in vitro antimicrobial activity

This study reports the synthesis, characterisation and antimicrobial activity of five novel silver N-heterocyclic carbene (Ag–NHC) complexes obtained by N-propylphthalimide and N-methyldioxane substituted benzimidazolium salts with silver oxide. The reactions were performed at room temperature for 24?h in the absence of light. The obtained complexes were identified and characterised by ¹H and ¹³C NMR, FT-IR and elemental analysis techniques. The minimum inhibitory concentration (MIC) of the complexes was determined for E. coli, P. aeruginosa, E. faecalis, S. aureus, C. tropicalis and C. albicans in vitro through agar and broth dilution. The results indicated that these complexes exhibit antimicrobial activity. In particular, complex 3 presented the significant broad spectrum antimicrobial activity.     

HDAC6 at the intersection of autophagy, the ubiquitin-proteasome system and neurodegeneration

The two major intracellular catabolic pathways, the ubiquitin-proteasome system (UPS) and macroautophagy (autophagy), have each been implicated as playing roles in neurodegenerative proteinopathies. We have investigated the relationship between the UPS and autophagy using Drosophila models of neurodegenerative diseases. We identified histone deacetylase 6 (HDAC6) as a genetic modifier of polyglutamine-induced neurodegeneration and determined that its mechanism of action is autophagy-dependent. The ability of HDAC6 to suppress degeneration has been extended to additional neurodegenerative disease models, including a fly model expressing pathological Abeta fragments, presented here, but is not a universal modifier of degenerative phenotypes. Importantly, HDAC6 was also found to suppress degeneration associated with proteasome mutations in an autophagy-dependent manner, revealing a compensatory relationship between these two degradation pathways. Our findings indicate that HDAC6 facilitates degradation of potentially noxious protein substrates, contributing vitally to the neuroprotective role of autophagy.