149 research outputs found

    Polynucleotide encoding a gene conferring resistance to Bacillus thuringiensis toxins

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    Nucleic acid (DNA) probes are provided which will specifically identify a gene for resistance of Bt in insect populations. Sequences are identified associated with the onset of resistance to Bacillus thuringiensis toxins. The sequences are used as probes to monitor the presence of acquired insect resistance associated with transgenic crops

    Gelatinous versus non-gelatinous zooplankton: their value as food for planktivorous coral reef fishes

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    Coral reefs are highly productive ecosystems, in part due to the productivity of planktivorous fishes. The planktivorous fish community contains two distinct groups which target either the gelatinous or the non-gelatinous fractions of the incoming zooplankton. However, the nutritional value of these prey fractions and, consequently, their potential contribution to planktivorous fish productivity are poorly understood. We explored the zooplankton fractions potential contribution to planktivorous fish productivity (our function of interest), by quantifying the nutritional content a key trait of the gelatinous and non-gelatinous prey fractions which are accessible to reef-associated diurnal planktivores. By combining vertical plankton tows with stoichiometric analyses, we found that the three zooplankton community fractions—gelatinous, > 2 mm non-gelatinous and 2 mm non-gelatinous (0.06 gN) and gelatinous (0.03 gN) communities, respectively. Overall, our results highlight the quality of both gelatinous and non-gelatinous zooplankton as prey for planktivorous fishes, emphasizing the potential importance of the often-overlooked gelatinous fraction

    Spectroscopic and mechanistic studies of dinuclear metallohydrolases and their biomimetic complexes

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    An enhanced understanding of the metal ion binding and active site structural features of phosphoesterases such as the glycerophosphodiesterase from Enterobacter aerogenes (GpdQ), and the organophosphate degrading agent from Agrobacterium radiobacter (OpdA) have important consequences for potential applications. Coupled with investigations of the metalloenzymes, programs of study to synthesise and characterise model complexes based on these metalloenzymes can add to our understanding of structure and function of the enzymes themselves. This review summarises some of our work and illustrates the significance and contributions of model studies to knowledge in the area

    The organophosphate-degrading enzyme from Agrobacterium radiobacter displays mechanistic flexibility for catalysis

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    The OP (organophosphate)-degrading enzyme from Agrobacterium radiobacter (OpdA) is a binuclear metallohydrolase able to degrade highly toxic OP pesticides and nerve agents into less or non-toxic compounds. In the present study, the effect of metal ion substitutions and site-directed mutations on the catalytic properties of OpdA are investigated. The study shows the importance of both the metal ion composition and a hydrogenbond network that connects the metal ion centre with the substrate-binding pocket using residues Arg254 and Tyr257 in the mechanism and substrate specificity of this enzyme. For theCo(II) derivative of OpdA two protonation equilibria (pKa1 ∼5; pKa2 ∼10) have been identified as relevant for catalysis, and a terminal hydroxide acts as the likely hydrolysis-initiating nucleophile. In contrast, the Zn(II) and Cd(II) derivatives only have one relevant protonation equilibrium (pKa ∼4–5), and theμOHis the proposed nucleophile. The observed mechanistic flexibility may reconcile contrasting reaction models that have been published previously and may be beneficial for the rapid adaptation of OP-degrading enzymes to changing environmental pressures

    A one-year prospective study of the safety, tolerability and pharmacokinetics of the highest available dose of paliperidone palmitate in patients with schizophrenia

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    <p>Abstract</p> <p>Background</p> <p>There are no previous reports of paliperidone palmitate's (PP) long term tolerability or pharmacokinetics of the highest dose in patients with schizophrenia. This study evaluates safety and tolerability, as well as pharmacokinetics, of the highest marketed dose of PP (150 mg eq. [234 mg]) in stable patients with schizophrenia over a 1-year period.</p> <p>Methods</p> <p>In this 1-year prospective study, eligible patients (aged 18-65 years; Positive and Negative Syndrome Scale's total score ≤ 70) received an initial deltoid injection of PP 150 mg eq. The second injection one week later and subsequent once-monthly injections were deltoid or gluteal. All injections were to be PP 150 mg eq. Patients willing to participate in intensive pharmacokinetic sampling were classified as Treatment A. Patients unwilling to undergo intensive pharmacokinetic sampling or unable to tolerate the 150 mg eq. dose (consequently receiving flexible doses of 50, 100 or 150 mg eq.) were classified as Treatment B.</p> <p>Results</p> <p>Of the 212 patients (safety analysis set), 73% were men; 45% white; 20% black; 34% Asians; mean (SD) age 41 (10.2) years, and mean (SD) baseline Positive and Negative Syndrome Scale total score 54.9 (9.03). A total of 53% (n = 113) patients completed the study and 104 received PP 150 mg eq. throughout. Mean (SD) mode dose of PP was 144.8 (19.58) mg eq. The dosing initiation regimen resulted in rapidly achieved and maintained therapeutic paliperidone levels over the study (average concentrations during the dosing interval were 34.7, 40.0, and 47.8 ng/mL after the 2nd, 8th, and 14th injection respectively). Most frequent (≥ 10%) treatment-emergent adverse events were nasopharyngitis (n = 37), insomnia (n = 32), injection-site pain (n = 32), headache (n = 28), and tachycardia (n = 27). Akathisia (n = 19) and tremor (n = 11) were the most common extrapyramidal adverse events. 33 patients had an SAE and 27 discontinued due to treatment-emergent adverse events. No deaths were reported. Mean (SD) weight change from baseline was 2.5 (5.41) kg at endpoint. Patients' psychoses remained stable.</p> <p>Conclusions</p> <p>Safety results after one-year therapy with the highest available dose of once-monthly paliperidone palmitate were consistent with results from previous studies, with no new concerns noted. Plasma concentrations were within the expected range.</p> <p>Trial registration no</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01150448">NCT01150448</a></p

    Inflammation-induced DNA damage and damage-induced inflammation: a vicious cycle

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    Inflammation is the ultimate response to the constant challenges of the immune system by microbes, irritants or injury. The inflammatory cascade initiates with the recognition of microorganism-derived pathogen associated molecular patterns (PAMPs) and host cell-derived damage associated molecular patterns (DAMPs) by the pattern recognition receptors (PRRs). DNA as a molecular PAMP or DAMP is sensed directly or via specific binding proteins to instigate pro-inflammatory response. Some of these DNA binding proteins also participate in canonical DNA repair pathways and recognise damaged DNA to initiate DNA damage response. In this review we aim to capture the essence of the complex interplay between DNA damage response and the pro-inflammatory signalling through representative examples

    Rationale and Methods for a Multicenter Clinical Trial Assessing Exercise and Intensive Vascular Risk Reduction in Preventing Dementia (rrAD Study)

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    Alzheimer\u27s Disease (AD) is an age-related disease with modifiable risk factors such as hypertension, hypercholesterolemia, obesity, and physical inactivity influencing the onset and progression. There is however, no direct evidence that reducing these risk factors prevents or slows AD. The Risk Reduction for Alzheimer\u27s Disease (rrAD) trial is designed to study the independent and combined effects of intensive pharmacological control of blood pressure and cholesterol and exercise training on neurocognitive function. Six hundred and forty cognitively normal older adults age 60 to 85 years with hypertension and increased risk for dementia will be enrolled. Participants are randomized into one of four intervention group for two years: usual care, Intensive Reduction of Vascular Risk factors (IRVR) with blood pressure and cholesterol reduction, exercise training (EX), and IRVR+EX. Neurocognitive function is measured at baseline, 6, 12, 18, and 24 months; brain MRIs are obtained at baseline and 24 months. We hypothesize that both IRVR and EX will improve global cognitive function, while IRVR+EX will provide a greater benefit than either IRVR or EX alone. We also hypothesize that IRVR and EX will slow brain atrophy, improve brain structural and functional connectivity, and improve brain perfusion. Finally, we will explore the mechanisms by which study interventions impact neurocognition and brain. If rrAD interventions are shown to be safe, practical, and successful, our study will have a significant impact on reducing the risks of AD in older adults. NCT Registration: NCT02913664
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