Effects of vitamin C on liver enzymes and biochemical parameters in rats anesthetized with halothane

Halothane is an important human and veterinary anesthetic, which produces free radicals during biotransformation. Occasionally, these free radicals may cause hepatic injury, especially in case of multiple halothane exposures over short periods. Vitamin C may protect cellular lipids and lipoproteins against oxidative damage by the free radicals. This study investigated the effects of vitamin C on liver enzymes and other biochemical parameters in rats anesthetized with halothane. One group of rats was used as a control, and saline (0.9% NaCl) was injected intraperitoneally into these animals as a placebo. The second group of rats was used as an anesthesia control group and was only anesthetized by halothane for 2 h. The third group was anesthetized by halothane and injected vitamin C intraperitoneally. Activities of aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase enzymes were significantly increased (p < 0.05, p < 0.01, p < 0.05, respectively) by halothane anesthesia, but decreased (p < 0.05, p < 0.05, p < 0.05, respectively) with administration of vitamin C. Concentrations of triglycerides, cholesterol, total bilirubin and creatinine were statistically affected (p < 0.05, p < 0.01, p < 0.05, and p < 0.01, respectively) by injection of vitamin C. Values of erythrocyte counts, packet cell volumes, hemoglobin concentration, leukocyte counts, rates of neutrophils and lymphocytes were significantly affected (p < 0.01, p < 0.05, p < 0.05, p < 0.01, p < 0.001 and p < 0.01, respectively) by halothane anesthesia. The values of erythrocyte counts, leukocyte counts, neutrophil and lymphocyte rates were significantly decreased (p < 0.05, p < 0.05, p < 0.05, p < 0.01 and p < 0.01, respectively) with administration of vitamin C. Based upon these results, vitamin C may play an important role in the prevention of hepatic cellular injury inflicted by halothane anesthesia.     

A new polymorphism in the type II deiodinase gene is associated with circulating thyroid hormone parameters

Type II deiodinase (D2) is important in the regulation of local thyroid hormone bioactivity in certain tissues. D2 in skeletal muscle may also play a role in serum triiodothyronine (T(3)) production. In this study, we identified a polymorphism in the 5'-UTR of the D2 gene (D2-ORFa-Gly3Asp). We investigated the association of D2-ORFa-Gly3Asp, and of the previously identified D2-Thr92Ala polymorphism, with serum iodothyronine levels. D2-ORFa-Gly3Asp was identified by sequencing the 5'-UTR of 15 randomly selected individuals. Genotypes for D2-ORFa-Gly3Asp were determined in 156 healthy blood donors (age 46.3 +/- 12.2 yr) and 349 ambulant elderly men (age 77.7 +/- 3.5 yr) and related to serum iodothyronine and TSH levels. D2-ORFa-Asp(3) had an allele frequency of 33.9% in blood bank donors and was associated with serum thyroxine (T(4); Gly/Gly vs. Gly/Asp vs. Asp/Asp = 7.06 +/- 0.14 vs. 6.74 +/- 0.15 vs. 6.29 +/- 0.27 microg/dl, P = 0.01), free T(4) (1.22 +/- 0.02 vs. 1.16 +/- 0.02 vs. 1.06 +/- 0.04 ng/dl, P = 0.001), reverse T(3) (P = 0.01), and T(3)/T(4) ratio (P = 0.002) in a dose-dependent manner, but not with serum T(3) (P = 0.59). In elderly men, D2-ORFa-Asp(3) had a similar frequency but was not associated with serum iodothyronine levels. This new polymorphism in the 5'-UTR of D2 is associated with iodothyronine levels in blood donors but not in elderly men. We hypothesize that this might be explained by the decline in skeletal muscle size during aging, resulting in a relative decrease in the contribution of D2 to serum T(3) production.     

Organization of the CTX prophage in environmental isolates of Vibrio mimicus

The organization of the CTX prophage in environmental strains of Vibrio mimicus was investigated. Sixteen hundred non-sucrose fermenting vibrios were examined for ctx gene by hybridization. Out of 1,600 isolates, 6 V. mimicus isolates contained ctxA gene. The organization of CTX prophage was determined by RFLP using ctxA probe. The CTX prophage integrated at a single site in V. mimicus genome which was present as a single copy flanked by at least a single RS element. Ribotype pattern revealed that a particular clone of V. mimicus acquired the CTXPhi in the aquatic environment. This study demonstrated that V. mimicus could act as a reservoir of CTXPhi in the aquatic environment.     

Structure-based design and synthesis of pyrazinones containing novel P1 'side pocket' moieties as inhibitors of TF/VIIa

We describe the structure-based design, synthesis, and enzymatic activity of a series of substituted pyrazinones as inhibitors of the TF/VIIa complex. These inhibitors contain substituents meta to the P(1) amidine designed to explore additional interactions with the VIIa residues in the so-called 'S(1) side pocket'. A crystal structure of the designed inhibitors demonstrates the ability of the P(1) side pocket moiety to engage Lys192 and main chain of Gly216 via hydrogen bond interactions, thus, providing additional possibility for chemical modification to improve selectivity and/or physical properties of inhibitors.     

Role of reactive oxygen species in the regulation of Arabidopsis seed dormancy

Freshly harvested seeds of Arabidopsis thaliana, Columbia (Col) accession were dormant when imbibed at 25°C in the dark. Their dormancy was alleviated by continuous light during imbibition or by 5 weeks of storage at 20°C (after-ripening). We investigated the possible role of reactive oxygen species (ROS) in the regulation of Col seed dormancy. After 24 h of imbibition at 25°C, non-dormant seeds produced more ROS than dormant seeds, and their catalase activity was lower. In situ ROS localization revealed that germination was associated with an accumulation of superoxide and hydrogen peroxide in the radicle. ROS production was temporally and spatially regulated: ROS were first localized within the cytoplasm upon imbibition of non-dormant seeds, then in the nucleus and finally in the cell wall, which suggests that ROS play different roles during germination. Imbibition of dormant and non-dormant seeds in the presence of ROS scavengers or donors, which inhibited or stimulated germination, respectively, confirmed the role of ROS in germination. Freshly harvested seeds of the mutants defective in catalase (cat2-1) and vitamin E (vte1-1) did not display dormancy; however, seeds of the NADPH oxidase mutants (rbohD) were deeply dormant. Expression of a set of genes related to dormancy upon imbibition in the cat2-1 and vet1-1 seeds revealed that their non-dormant phenotype was probably not related to ABA or gibberellin metabolism, but suggested that ROS could trigger germination through gibberellin signaling activation.     

Physiological changes induced by chromium stress in plants: an overview

This article presents an overview of the mechanism of chromium (Cr) stress in plants. Toxic effects of Cr on plant growth and development depend primarily on its valence state. Cr(VI) is highly toxic and mobile whereas Cr(III) is less toxic. Cr-induced oxidative stress involves induction of lipid peroxidation in plants that cause severe damage to cell membranes which includes degradation of photosynthetic pigments causing deterioration in growth. The potential of plants with the adequacy to accumulate or to stabilize Cr compounds for bioremediation of Cr contamination has gained engrossment in recent years.     

Salicylic acids: Local,systemic or inter-systemic regulators?

Salicylic acid is well known phytohormone, emerging recently as a new paradigm of an array of manifestations of growth regulators. The area unleashed yet encompassed the applied agriculture sector to find the roles to strengthen the crops against plethora of abiotic and biotic stresses. The skipped part of integrated picture, however, was the evolutionary insight of salicylic acid to either allow or discard the microbial invasion depending upon various internal factors of two interactants under the prevailing external conditions. The metabolic status that allows the host invasion either as pathogenesis or symbiosis with possible intermediary stages in close systems has been tried to underpin here.     

Sterically Stabilized Phospholipid Micelles Reduce Activity of a Candidate Antimicrobial Wound Healing Adjunct

KSLW is an antimicrobial decapeptide, presumed to associate with micelles. Linear polymeric chains of hydrophobic phospholipids tend to form micelles, spontaneously, and function as efficient drug-stabilizing delivery systems. Our goal was to examine whether association of a cationic decapeptide with sterically stabilized nanomicelles (SSMs), improves stability and antimicrobial effect in vivo, using an impaired healing model. KSLW solutions were prepared in either saline or 12?mM SSM. Bilateral circular excisional wounds were created on the backs of SKH-1 mice followed by intradermal delivery of peptide solutions. Bacterial assays were conducted to assess bioactivity of KSLW in different formulations. Fluorescence analyses demonstrated an optimum lipid:peptide ratio for loading KSLW in PEGylated phospholipid micelles to be 15:1. Stressed animals treated with KSLW?CSSM preparations demonstrated no differences in microbial load at post-operative time points. In vitro assays against Staphylococcus epidermidis confirmed diminished activity of KSLW in SSM solution. The loss of KSLW antimicrobial activity may be based on electrostatic interactions with the anionic surface of SSM, which interfere with the peptide??s interaction with bacterial membranes. This study emphasizes the importance of antimicrobial peptide charge, size, and bioactivity, when designing delivery systems for wound healing agents.     

A linear ablating system in the left and right atrium: feasibility, catheter performance and clinical results

IntroductionWe describe the use of a ablating system to compartmentalise and regionally isolate the atria in paroxysmal and persistent atrial fibrillation (AF).Methods40 patients were studied, 25 paroxysmal AF and 14 persistent AF. One patient enrolled was later found to be in left atrial flutter and was excluded. The Cardima Revelation® TX catheter system with Intellitemp® Radiofrequency (RF) energy control device and a Medtronic Atakar® RF generator were used to place wide area circumferential ablations to achieve conduction block into the left and right sided pulmonary veins. Roof lines and mitral isthmus lines were also performed. In patients with persistent AF and in repeat procedures, right atrial compartmentalisation was performed with an anterior superior vena cava (SVC) to inferior vena cava (IVC) line and a septal SVC to IVC line.ResultsAt 6 months, 18 of the 39 patients were asymptomatic, 10 had improved symptoms and 22 were in sinus rhythm. In the paroxysmal group, 11 were asymptomatic, 7 had improved symptoms and 16 (64%) were in sinus rhythm. In the persistent group, 7 were asymptomatic, 3 had improved symptoms and 6 (43%) were in sinus rhythm. The total group AF burden was 37.8 ± 5.4 hrs pre-procedure and 23.1 ± 5.1 hrs at 6 months post procedure. Mean temperature, impedance and power recorded at each pole demonstrated effective power delivery at all poles. No catheter charring was observed, complication rates were comparable to standard AF ablation technique.ConclusionLinear ablation in the left and right atria to mimic Cox’s Maze is feasible and safe using this ablating system.