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关键词： Organophosphorus pesticides   Methyl parathion hydrolase   Thermostability   Bioremediation   PICHIA-PASTORIS   CELL-SURFACE   PHOSPHOTRIESTERASE   THERMOSTABILITY   BIODEGRADATION   EXPRESSION   PROTEINS   HOMOLOG   DISPLAY   ENZYME  

摘要： Organophosphorus pesticides are highly toxic phosphate compounds with the general structure of O = P(OR)(3) and threaten human health seriously. Methyl parathion hydrolase from microbial is an important enzyme to degrade organophosphorus pesticides (OPs) into less toxic or nontoxic compounds like. p-nitrophenol and diethyl phosphate. Here, a gene encoding methyl parathion hydrolase from Azohydromonas australica was firstly cloned and expressed in Escherichia coli. The recombinant hydrolase showed its optimal pH and temperature at pH 9.5 and 50 degrees C. Leveraging 1 mM Mn2+, the enzyme activity was significantly enhanced by 29.3-fold, and the thermostability at 40 and 50 degrees C was also improved. The recombinant MPH showed the specific activity of 4.94 and 16.0 U/mg towards methyl parathion and paraoxon, respectively. Moreover, A. australica MPH could effectively degrade various of OPs pesticides including methyl parathion, paraoxon, dichlorvos and chlorpyrifos in a few minutes, suggesting a great potential in the bioremediation of OPs pesticides.

关键词： alpha 1 receptor blockers   biochemical relapse   concomitant medications   localised prostate cancer   metformin   radiotherapy   BEAM RADIATION-THERAPY   RADICAL PROSTATECTOMY   METFORMIN   MEN   MORTALITY   TRIAL   RISK   ANTAGONIST   SENESCENCE   REGRESSION  

摘要： Aims: Several classes of concomitant medications have been shown to affect oncological outcomes in patients with prostate cancer (PCa). We assessed the association between the use of commonly prescribed concomitant medications and biochemical relapse-free survival (bRFS) in patients with localised PCa treated with radiotherapy and androgen deprivation therapy (ADT). Materials and methods: A secondary pooled analysis of two phase III randomised trials was carried out. In the first trial, patients with localised PCa with clinical stage T1b-T3, prostate-specific antigen <30 ng/ml and Gleason score <= 7 were treated with radical radiotherapy and 6 months of ADT starting 4 months before or concomitantly with radiotherapy. In the second trial, patients with high-risk PCa were treated with radical radiotherapy and 36 months of ADT with randomisation to three-dimensional conformal or intensity-modulated radiotherapy. Information on concomitant medications was collected from the medical record. Univariable and multivariable Cox regression was used to identify factors associated with bRFS. Results: Overall, 486 patients were evaluable. The median follow-up was 125 months; 10-year bRFS was 83.7%. On univariable analysis, receipt of metformin was significantly associated with worse bRFS. Ten-year bRFS was 73% and 85% for patients with and without concomitant metformin (adjusted hazard ratio 2.11, 95% confidence interval 1.03-4.33). Similar evidence of an association was observed with sulfonamide-based al-receptor blockers (adjusted hazard ratio 2.72, 95% confidence interval 1.31-5.66). However, no such association was seen with receipt of quinazoline-based al-receptor blockers (adjusted hazard ratio 1.09, 95% confidence interval 0.42-2.82). There was no significant association between bRFS and receipt of all other medication classes considered. Conclusions: In this population of patients with localised PCa treated with radiotherapy and ADT, receipt of concomitant metformin and

关键词： Metal   Toxicity   Amelioration   Antioxidant   Common carp   FRESH-WATER FISH   OXIDATIVE STRESS   VITAMIN-C   SEBASTES-SCHLEGELII   ALPHA-TOCOPHEROL   INDUCED TOXICITY   NILE TILAPIA   BIOACCUMULATION   PARAMETERS   RESPONSES  

摘要： The current study investigated the antioxidant potential of ascorbic acid to counteract arsenic induced toxic response in Cyprinus carpio. The 96 h LC50 of 107.05 mg L-1 was recorded through acute toxicity test and 1/5th and 1/10th LC50 of arsenic were chosen as sublethal concentrations for assessing toxicity induced through arsenic exposure in fish for a period of 28 days. There were six experimental groups for sublethal toxicity testing viz. negative control (basal feed), positive control (basal feed + 1 g kg(-1) diet ascorbic acid), 1/5th LC50 Arsenic, 1/10th LC50 Arsenic, 1/5th LC50 Arsenic with ascorbic acid supplement, 1/10th LC50 Arsenic with ascorbic acid supplement. Following exposure, blood indices, antioxidant enzyme activity and histomorphology of gills, liver and kidney were examined. The results showed decreased total erythrocyte count, haemoglobin, haematocrit and an increased total leukocyte count upon arsenic exposure in fish with an improvement observed in the blood indices in arsenic with ascorbic acid supplementation. The study also analysed the antioxidant enzyme activity of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione-S-transferase which was found to decline in response to arsenic exposure with an increase in their activity recorded in arsenic with ascorbic acid supplemented fish. Furthermore, uptake of arsenic was also found to decrease on ascorbic acid supplementation with improvement in the histoarchitecture of gills, liver and kidney of fish. Collectively, the findings of the present study suggest the effectiveness of ascorbic acid as an ameliorating agent against the deleterious effects of arsenic in fish.

关键词： canopy conductance   grassland   isotope‐enabled soil–vegetation–atmosphere transfer model (MuSICA)   O-18‐enrichment of cellulose oxygen isotope composition of cellulose   perennial ryegrass (Lolium perenne)   relative humidity   temperature   OXYGEN-ISOTOPE RATIOS   TREE-RING CELLULOSE   STOMATAL CONDUCTANCE   STABLE-ISOTOPES   O-18 ENRICHMENT   CARBON-DIOXIDE   ELEVATED CO2   PHLOEM SAP   LIFE-SPAN   GROWTH  

摘要： We explore here our mechanistic understanding of the environmental and physiological processes that determine the oxygen isotope composition of leaf cellulose (delta O-18(cellulose)) in a drought-prone, temperate grassland ecosystem. A new allocation-and-growth model was designed and added to an O-18-enabled soil-vegetation-atmosphere transfer model (MuSICA) to predict seasonal (April-October) and multi-annual (2007-2012) variation of delta O-18(cellulose) and O-18-enrichment of leaf cellulose (Delta O-18(cellulose)) based on the Barbour-Farquhar model. Modelled delta O-18(cellulose) agreed best with observations when integrated over c. 400 growing-degree-days, similar to the average leaf lifespan observed at the site. Over the integration time, air temperature ranged from 7 to 22 degrees C and midday relative humidity from 47 to 73%. Model agreement with observations of delta O-18(cellulose) (R-2 = 0.57) and Delta O-18(cellulose) (R-2 = 0.74), and their negative relationship with canopy conductance, was improved significantly when both the biochemical O-18-fractionation between water and substrate for cellulose synthesis (epsilon(bio), range 26-30 parts per thousand) was temperature-sensitive, as previously reported for aquatic plants and heterotrophically grown wheat seedlings, and the proportion of oxygen in cellulose reflecting leaf water O-18-enrichment (1 - p(ex)p(x), range 0.23-0.63) was dependent on air relative humidity, as observed in independent controlled experiments with grasses. Understanding physiological information in delta O-18(cellulose) requires quantitative knowledge of climatic effects on p(ex)p(x) and epsilon(bio).

关键词： Mycobacterium tuberculosis   FtsY   SRP pathway   GTP   CD   SIGNAL-RECOGNITION PARTICLE   ELONGATION-FACTOR-TU   ESCHERICHIA-COLI   PROTEIN-STRUCTURE   ATPASE ACTIVITY   RECEPTOR   GTP   BINDING   FFH   EXPRESSION  

摘要： Mycobacterium tuberculosis (M. tuberculosis H(37)Rv) utilizes the signal recognition particle pathway (SRP pathway) system for secretion of various proteins from ribosomes to the extracellular surface which plays an important role in the machinery running inside the bacterium. This system comprises of three major components FtsY, FfH and 4.5S rRNA. This manuscript highlights essential factors responsible for the optimized enzymatic activity of FtsY. Kinetic parameters include V-max and K-m for the hydrolysis of GTP by ftsY which were 20.25 +/- 5.16 mu M/min/mg and 39.95 +/- 7.7 mu M respectively. k(cat) and catalytic efficiency of the reaction were 0.012 +/- 0.003 s(-1) and 0.00047 +/- 0.0001 mu M/s(-1) respectively. These values were affected upon changing the standard conditions. Cations (Mg2+ and Mn2+) play important role in FtsY enzymatic activity as increasing Mg2+ decrease the activity. Mn2+ on the other hand is required at higher concentration around 60 mM for carrying optimum GTPase activity. FtsY is hydrolyzing ATP and GDP as well and GDP acts as an inhibitor of the reaction. MD simulation shows effective binding and stabilization of the FtsY complexed structure with GTP, GDP and ATP. Mutational analysis was done at two important residues of GTP binding motif of FtsY, namely, GXXXXGK (K236) and DXXG (D367) and showed that these mutations significantly decrease FtsY GTPase activity. FtsY is comprised of alpha helices, but this structural pattern was shown to change with increasing concentrations of GTP and ATP which symbolize that these ligands cause significant conformational change by variating the secondary structure to transduce signals required by downstream effectors. This binding favors the functional stabilization of FtsY by destabilization of alpha-helix integrity. Revealing the hidden aspects of the functioning of FtsY might be an essential part for the understanding of the SRP pathway which is one of the important contributors of M. tuberculosis v

关键词： Anesthetic   Stress   Physiology   Metabolism   GRATISSIMUM ESSENTIAL OIL   JUVENILE TAMBAQUI   PHYSIOLOGICAL-RESPONSES   OREOCHROMIS-NILOTICUS   SPILANTHES-ACMELLA   RHAMDIA-QUELEN   NILE TILAPIA   CLOVE OIL   STRESS   L.  

摘要： The present study evaluated the efficacy of Ocimum basilicum (basil) essential oil in the anesthetic induction and recovery of juvenile tambaqui Colossoma macropomum and verified its physiometabolic effects after biometric handling. Juveniles (86.51 +/- 7.82 g) were exposed to different concentrations of basil essential oil: 400, 500, 600, 700, 800, 900, and 1000 mu L L-1. Subsequently, the fish were divided into five groups: control (non-handled fish), handling without anesthetic (water only), handling with ethanol (720 mu L L-1), and handling with Ocimum basilicum essential oil (400 and 800 mu L L-1). The shortest (p < 0.05) time to induce anesthesia was at a concentration of 1000 mu L L-1 (222 s). The recovery time from anesthesia did not differ significantly among different concentrations (400-1000 mu L L-1). The results of the present study confirm the essential oil of O. basilicum as a new and safe natural anesthetic for juvenile tambaqui. The use of this essential oil in biometrics handling procedures reduces or attenuates the secondary responses to handling stress without showing deleterious effects on the non-specific immune system or metabolism of energy, carbohydrates, and lipids. However, further studies are necessary to determine the exact mechanism of action of this essential oil.