Effect of plant nutrition on aphid size,prey consumption,and life history characteristics of green lacewing

Plant quality can directly and indirectly affect the third trophic level. The predation by all the instars of green lacewing, Chrysoperla carnea （S.） （Neuroptera： Chrysopidae） on the cereal aphids, Rhopalosiphum padi （L.）, and Sitobion avenae （F.） at varying nitrogen fertilizer levels was calculated under laboratory conditions. Wheat plants were grown on four nitrogen fertilizer levels and aphids were fed on these plants and subsequently offered as food to the C. carnea. Aphid densities of 10, 30, and 90 were offered to first, second, and third instar larvae of green lacewing. Increased nitrogen application improved nitrogen contents of the plants and also the body weight of cereal aphids feeding on them. Aphid consumption by green lacewings was reduced with the increase in nitrogen content in the host plants of aphids. Predation of both aphid species by first, second, and third instars larvae of C. carnea was highest on aphids reared on plants with the lowest rate of fertilization, suggesting a compensatory consumption to overcome reduced biomass （lower aphid size）. Total biomass devoured by C. carnea on all nitrogen fertilizer treatments was not statistically different. Additionally, the heavier host prey influenced by the plant nutrition had an effect on the life history characteristics of green lacewings. The larval duration, pupal weight, pupal duration, fecundity, and male and female longevity were significantly affected by the level of nitrogen fertilization to the aphid＇s host plants, except for pupal duration when fed on S. avenae. This study showed that quantity of prey supplied to the larvae affects the prey consumption and thereafter the life history characteristics of green lacewings.     

Chronic Intermittent Hypoxia Is Independently Associated with Reduced Postoperative Opioid Consumption in Bariatric Patients Suffering from Sleep-Disordered Breathing

BackgroundEvidence suggests that recurrent nocturnal hypoxemia may affect pain response and/or the sensitivity to opioid analgesia. We tested the hypothesis that nocturnal hypoxemia, quantified by sleep time spent at an arterial saturation (SaO₂) < 90% and minimum nocturnal SaO₂ on polysomnography, are associated with decreased pain and reduced opioid consumption during the initial 72 postoperative hours in patients having laparoscopic bariatric surgery.MethodsWith Institutional Review Board approval, we examined the records of all patients who underwent laparoscopic bariatric surgery between 2004 and 2010 and had an available nocturnal polysomnography study. We assessed the relationships between the time-weighted average of pain score and total opioid consumption during the initial 72 postoperative hours, and: (a) the percentage of total sleep time spent at SaO₂ < 90%, (b) the minimum nocturnal SaO₂, and (c) the number of apnea/hypopnea episodes per hour of sleep. We used multivariable regression models to adjust for both clinical and sleep-related confounders.ResultsTwo hundred eighteen patients were included in the analysis. Percentage of total sleep time spent at SaO₂ < 90% was inversely associated with total postoperative opioid consumption; a 5-%- absolute increase in the former would relatively decrease median opioid consumption by 16% (98.75% CI: 2% to 28%, P = 0.006). However, the percentage of total sleep time spent at SaO₂ < 90% was not associated with pain. The minimum nocturnal SaO₂ was associated neither with total postoperative opioid consumption nor with pain. In addition, neither pain nor total opioid consumption was significantly associated with the number of apnea/hypopnea episodes per hour of sleep.ConclusionsPreoperative nocturnal intermittent hypoxia may enhance sensitivity to opioids.     

Nano-TiO2 Is Not Phytotoxic As Revealed by the Oilseed Rape Growth and Photosynthetic Apparatus Ultra-Structural Response

Recently nano-materials are widely used but they have shown contrasting effects on human and plant life. Keeping in view the contrasting results, the present study has evaluated plant growth response, antioxidant system activity and photosynthetic apparatus physiological and ultrastructural changes in Brassica napus L. plants grown under a wide range (0, 500, 2500, 4000 mg/l) of nano-TiO₂ in a pot experiment. Nano-TiO₂ has significantly improved the morphological and physiological indices of oilseed rape plants under our experimental conditions. All the parameters i-e morphological (root length, plant height, fresh biomass), physiological (photosynthetic gas exchange, chlorophyll content, nitrate reductase activity) and antioxidant system (Superoxide dismutase, SOD; Guaiacol peroxidase, POD; Catalase, CAT) recorded have shown improvement in their performance by following nano-TiO₂ dose-dependent manner. No significant chloroplast ultra-structural changes were observed. Transmission electron microscopic images have shown that intact & typical grana and stroma thylakoid membranes were in the chloroplast, which suggest that nano-TiO₂ has not induced the stressful environment within chloroplast. Finally, it is suggested that, nano-TiO₂ have growth promoting effect on oilseed rape plants.     

Elucidating the molecular interaction of serum albumin with nizatidine and the role of β-cyclodextrin: multi-spectroscopic and computational approach

Abstract

Nizatidine is a histamine H2 receptor antagonist which act by inhibiting the production of stomach acid, thereby, finds its application in treating various diseases related to the gastrointestinal tract. Studying albumin–drug interaction is important for understanding the pharmacokinetics and pharmacodynamics of therapeutic candidates. In the present work, the interaction of nizatidine with BSA was investigated by employing multi-spectroscopic and computational studies. The formation of BSA–nizatidine complex was characterised by UV-visible and fluorescence based-spectroscopic studies. Steady-state fluorescence demonstrated the static mode of quenching of BSA by nizatidine. The interaction was spontaneous and nizatidine binds to BSA with a stoichiometry of 1:1. Forster resonance energy transfer calculations revealed that there was a high possibility of energy transfer between nizatidine and BSA. The resultant secondary structural change in BSA on the addition of nizatidine was studied by circular dichroism spectroscopy. Moreover, synchronous and three-dimensional fluorescence spectroscopy was used to determine the conformational changes occurred in the structure of albumin on the binding of nizatidine. Competitive-site marker experiments suggested that nizatidine binds in the Sudlow site II of BSA. Additionally, the effect of β-cyclodextrin as an inclusion compound on the interaction was studied. Furthermore, molecular modelling and simulation studies were performed to corroborate the results obtained above.

Communicated by Ramaswamy H. Sarma     

Not so robust: Robusta coffee production is highly sensitive to temperature

Coffea canephora (robusta coffee) is the most heat‐tolerant and ‘robust’ coffee species and therefore considered more resistant to climate change than other types of coffee production. However, the optimum production range of robusta has never been quantified, with current estimates of its optimal mean annual temperature range (22–30°C) based solely on the climatic conditions of its native range in the Congo basin, Central Africa. Using 10 years of yield observations from 798 farms across South East Asia coupled with high‐resolution precipitation and temperature data, we used hierarchical Bayesian modeling to quantify robusta's optimal temperature range for production. Our climate‐based models explained yield variation well across the study area with a cross‐validated mean R² = .51. We demonstrate that robusta has an optimal temperature below 20.5°C (or a mean minimum/maximum of ≤16.2/24.1°C), which is markedly lower, by 1.5–9°C than current estimates. In the middle of robusta's currently assumed optimal range (mean annual temperatures over 25.1°C), coffee yields are 50% lower compared to the optimal mean of ≤20.5°C found here. During the growing season, every 1°C increase in mean minimum/maximum temperatures above 16.2/24.1°C corresponded to yield declines of ~14% or 350–460 kg/ha (95% credible interval). Our results suggest that robusta coffee is far more sensitive to temperature than previously thought. Current assessments, based on robusta having an optimal temperature range over 22°C, are likely overestimating its suitable production range and its ability to contribute to coffee production as temperatures increase under climate change. Robusta supplies 40% of the world's coffee, but its production potential could decline considerably as temperatures increase under climate change, jeopardizing a multi‐billion dollar coffee industry and the livelihoods of millions of farmers.     

Expression, Purification and Characterization of the Proline Dehydrogenase Domain of PutA from Pseudomonas putida POS-F84

The objective of the present work was to express a truncated form of Pseudomonas putida PutA that shows proline dehydrogenase (ProDH) activity. The putA gene encoding ProDH enzyme was cloned into pET23a vector and expressed in Escherichia coli strain BL-21 (DE3) plysS. The recombinant P. putida enzyme was biochemically characterized and its three dimensional structure was also predicted. ProDH encoding sequence showed an open reading frame of 1,035-bp encoding a 345 amino acid residues polypeptide chain. Purified His-tagged enzyme gave a single band with a molecular mass of 40 kDa on SDS-PAGE. The molecular mass of the isolated enzyme was found to be about 40 kDa by gel filtration. This suggested that the enzyme of interest consists of one subunit. The K _m and V _max values of recombinant P. putida ProDH were estimated to be 31 mM and 132 μmol/min, respectively. The optimum pH and temperature for the catalytic activity of the enzyme was about pH 8.5 and 30 °C. The modeling analysis of the three dimensional structure elucidated that Ser-165, Lys-195 and Ala-252 were key residues for the ProDH activity. This study provides data on the cloning, sequencing and recombinant expression of PutA ProDH domain from P. putida POS-F84.     

5-Aminolevulinic acid enhances photosynthetic gas exchange, chlorophyll fluorescence and antioxidant system in oilseed rape under drought stress

This study evaluates the role of exogenous foliar application of 5-aminolevulinic acid (ALA) on water relations, gas exchange, chlorophyll fluorescence, and the activities and gene expression patterns of antioxidant enzymes in leaves of oilseed rape under drought stress and recovery conditions. Seedlings at four-leaf stage were imposed to well-watered condition (80 % of water-holding capacity) or drought stress (40 % of water-holding capacity) and subsequently foliar sprayed with water or ALA (30 mg l^?1). Drought suppressed the accumulation of plant biomass and decreased chlorophyll content and leaf water status (relative water content and water potential). The actual quantum yield of photosystem II and electron transport rates were hampered in parallel to net photosynthetic rate. However, drought stress induced the accumulation of malondialdehyde (MDA) and hydrogen peroxide, enhanced the activities of catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), glutathione reductase (GR) and superoxide dismutase and up-regulated the expression of APX and GR. After rehydration for 4 days, the growth of drought-treated seedlings was restored to normal level for most of the physiological parameters. Foliar application of ALA maintained relatively higher leaf water status and enhanced chlorophyll content, net photosynthetic rate, actual quantum yield of photosystem II, photochemical quenching, non-photochemical quenching and electron transport rates in stressed leaves. Exogenous ALA also alleviated the accumulation of MDA and hydrogen peroxide, increased the activities of antioxidant enzymes and enhanced the expression of CAT and POD in drought-treated plants. These results indicate that ALA may effectively protect rapeseed seedlings from damage induced by drought stress.     

Appraisal of plant extracts and streptomycin sulfate against citrus canker disease

Abstract

Plant extracts and streptomycin sulfate were evaluated against Xanthomonas axonopodis pv. citri. In first experiment, Azadirachta indica, Allium cepa, Catharanthus roseus, Allium sativum, Zingiber officinale (Roscoe) were investigated in vitro through inhibition zone technique against the growth of X. a. pv. citri. Results indicated that A. indica exhibited statistically significant inhibition (4?cm) zone over control. In second experiment, A. indica and streptomycin sulfate disjointedly and in amalgamation were evaluated in vitro. Streptomycin alone and in permutation with A. indica articulated significant inhibition of the bacterium. In third study, streptomycin sulfate and A. indica (S) and in combination were evaluated against citrus canker disease in green house. Results showed that streptomycin sulfate reduced disease significantly than control. In fourth experiment, streptomycin sulfate, A. indica, in combination and their interaction with days were evaluated under field condition. Streptomycin sulfate proved to be most effective and reduced the disease severity as compared to control.     

Cannabinoid receptor agonist-induced apoptosis of human prostate cancer cells LNCaP proceeds through sustained activation of ERK1/2 leading to G1 cell cycle arrest

We have recently shown that the expression levels of both cannabinoid receptors CB(1) and CB(2) are higher in human prostate cancer cells than in normal prostate epithelial cells, and treatment of LNCaP cells with WIN-55,212-2 (a mixed CB(1)/CB(2) agonist) resulted in inhibition of cell growth and induction of apoptosis (Sarfaraz, S., Afaq, F., Adhami, V. M., and Mukhtar, H. (2005) Cancer Res. 65, 1635-1641). This study was conducted to understand the mechanistic basis of these effects. Treatment of LNCaP cells with WIN-55,212-2 (1-10 microm; 24 h) resulted in: (i) an arrest of the cells in the G(0)/G(1) phase of the cell cycle; (ii) an induction of p53 and p27/KIP1; (iii) down-regulation of cyclins D1, D2, E; (iii) decrease in the expression of cdk-2, -4, and -6; (iv) decrease in protein expression of pRb; (v) down-regulation of E2F (1-4); and (vi) decrease in the protein expression of DP1 and DP2. Similar effects were also observed when androgen-independent PC3 cells were treated with WIN-55,212-2 (5-30 microm). We further observed sustained up-regulation of ERK1/2 and inhibition of PI3k/Akt pathways in WIN-55,212-2-treated cells. Inhibition of ERK1/2 abrogated WIN-55,212-2-indued cell death suggesting that sustained activation of ERK1/2 leads to cell cycle dysregulation and arrest of cells in G(0)/G(1) phase subsequently leading to an induction of apoptosis. Further, WIN-55,212-2 treatment of cells resulted in a dose-dependent increase in Bax/Bcl-2 ratio in such a way that favors apoptosis. The induction of apoptosis proceeded through down-regulation of caspases 3, 6, 7, and 9 and cleavage of poly (ADP-ribose) polymerases. Based on these data we suggest that cannabinoid receptor agonists should be considered as novel agents for the management of prostate cancer.