Inner-sphere oxidation of ternary iminodiacetatochromium(III) complexes involving DL-valine and L-arginine as secondary ligands. Isokinetic relationship for the oxidation of ternary iminodiacetato-chromium(III) complexes by periodate

<p>Abstract</p> <p>Background</p> <p>In this paper, the kinetics of oxidation of [Cr^III(HIDA)(Val)(H₂O)₂]⁺and [Cr^III(HIDA)(Arg)(H₂O)₂]⁺(HIDA = iminodiacetic acid, Val = DL-valine and Arg = L-arginine) were studied. The choice of ternary complexes was attributed to two considerations. Firstly, in order to study the effect of the secondary ligands DL-valine and L-arginine on the stability of binary complex [Cr^III(HIDA)(IDA)(H₂O)] towards oxidation. Secondly, transition metal ternary complexes have received particular focus and have been employed in mapping protein surfaces as probes for biological redox centers and in protein capture for both purification and study.</p> <p>Results</p> <p>The results have shown that the reaction is first order with respect to both [IO₄^-] and the complex concentration, and the rate increases over the pH range 2.62 – 3.68 in both cases. The experimental rate law is consistent with a mechanism in which both the deprotonated forms of the complexes [Cr^III(IDA)(Val)(H₂O)₂] and [Cr^III(IDA)(Arg)(H₂O)₂] are significantly more reactive than the conjugate acids. The value of the intramolecular electron transfer rate constant for the oxidation of [Cr^III(HIDA)(Arg)(H₂O)₂]⁺, <it>k</it>₃(1.82 × 10^-3s^-1), is greater than the value of <it>k</it>₁(1.22 × 10^-3s^-1) for the oxidation of [Cr^III(HIDA)(Val)(H₂O)₂]⁺at 45.0°C and <it>I </it>= 0.20 mol dm^-3. It is proposed that electron transfer proceeds through an inner-sphere mechanism <it>via </it>coordination of IO₄^-to chromium(III).</p> <p>Conclusion</p> <p>The oxidation of [Cr^III(HIDA)(Val)(H₂O)₂]⁺and [Cr^III(HIDA)(Arg)(H₂O)₂]⁺by periodate may proceed through an inner-sphere mechanism via two electron transfer giving chromium(VI). The value of the intramolecular electron transfer rate constant for the oxidation of [Cr^III(HIDA)(Arg)(H₂O)₂]⁺, <it>k</it>₃, is greater than the value of <it>k</it>₁for the oxidation of [Cr^III(HIDA)(Val)(H₂O)₂]⁺. A common mechanism for the oxidation of ternary iminodiacetatochromium(III) complexes by periodate is proposed, and this is supported by an excellent isokinetic relationship between ΔH* and ΔS* values for these reactions.</p

Leprosy post-exposure prophylaxis with single-dose rifampicin

_Objective:_ Leprosy post-exposure prophylaxis with single-dose rifampicin (SDRPEP) has proven effective and feasible, and is recommended by WHO since 2018. This SDR-PEP toolkit was developed through the experience of the leprosy postexposure prophylaxis (LPEP) programme. It has been designed to facilitate and standardise the implementation of contact tracing and SDR-PEP administration in regions and countries that start the intervention. _Results:_ Four tools were developed, incorporating the current evidence for SDRPEP and the methods and learnings from the LPEP project in eight countries. (1) th

Status Update and Interim Results from the Asymptomatic Carotid Surgery Trial-2 (ACST-2)

Objectives: ACST-2 is currently the largest trial ever conducted to compare carotid artery stenting (CAS) with carotid endarterectomy (CEA) in patients with severe asymptomatic carotid stenosis requiring revascularization. Methods: Patients are entered into ACST-2 when revascularization is felt to be clearly indicated, when CEA and CAS are both possible, but where there is substantial uncertainty as to which is most appropriate. Trial surgeons and interventionalists are expected to use their usual techniques and CE-approved devices. We report baseline characteristics and blinded combined interim results for 30-day mortality and major morbidity for 986 patients in the ongoing trial up to September 2012. Results: A total of 986 patients (687 men, 299 women), mean age 68.7 years (SD ± 8.1) were randomized equally to CEA or CAS. Most (96%) had ipsilateral stenosis of 70-99% (median 80%) with contralateral stenoses of 50-99% in 30% and contralateral occlusion in 8%. Patients were on appropriate medical treatment. For 691 patients undergoing intervention with at least 1-month follow-up and Rankin scoring at 6 months for any stroke, the overall serious cardiovascular event rate of periprocedural (within 30 days) disabling stroke, fatal myocardial infarction, and death at 30 days was 1.0%. Conclusions: Early ACST-2 results suggest contemporary carotid intervention for asymptomatic stenosis has a low risk of serious morbidity and mortality, on par with other recent trials. The trial continues to recruit, to monitor periprocedural events and all types of stroke, aiming to randomize up to 5,000 patients to determine any differential outcomes between interventions. Clinical trial: ISRCTN21144362. © 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved

Leprosy post-exposure prophylaxis with single-dose rifampicin: toolkit for implementation

lNLR, Amsterdam, NetherlandsmPrivate, UKnHealth Services, Dadra and Nagar Haveli, IndiaoNLR, Jakarta, IndonesiapAnti-Leprosy Campaign, Colombo, Sri LankaqUniversidade do Estado de Mato Grosso, Ca ́ceres, BrazilrNational Tuberculosis and Leprosy Programme, Dar es Salaam,TanzaniasGerman Leprosy and Tuberculosis Relief Association, Wu ̈rzburg,GermanytDirectorate General of Health Services, MoHFW, New Delhi, IndiauNational Leprosy Elimination Program, Phnom Penh, CambodiavGerman Leprosy and Tuberculosis Relief Association,Dar es Salaam, TanzaniawSub Directorate Directly Transmitted Tropical Diseases, MoH,Jakarta, IndonesiaxErasmus MC, University Medical Center Rotterdam, Rotterdam,NetherlandsyAmerican Leprosy Missions, Greenville, USAzUniversity of Aberdeen, Aberdeen, UKaaFAIRMED, Colombo, Sri LankaabInstituto Lauro de Souza Lima, Bauru, BrazilAccepted for publication 22 July 2019SummaryObjective:Leprosy post-exposure prophylaxis with single-dose rifampicin (SDR-PEP) has proven effective and feasible, and is recommended by WHO since 2018.This SDR-PEP toolkit was developed through the experience of the leprosy post-exposure prophylaxis (LPEP) programme. It has been designed to facilitate andstandardise the implementation of contact tracing and SDR-PEP administration inregions and countries that start the intervention.Results:Four tools were developed, incorporating the current evidence for SDR-PEP and the methods and learnings from the LPEP project in eight countries. (1) theSDR-PEP policy/advocacy PowerPoint slide deck which will help to inform policymakers about the evidence, practicalities and resources needed for SDR-PEP, (2) theSDR-PEP field implementation training PowerPoint slide deck to be used to trainfront line staff to implement contact tracing and PEP with SDR, (3) the SDR-PEPgeneric field guide which can be used as a basis to create a location specific fieldprotocol for contact tracing and SDR-PEP serving as a reference for frontline fieldstaff. Finally, (4) the SDR-PEP toolkit guide, summarising the different componentsof the toolkit and providing instructions on its optimal use.Conclusion:In response to interest expressed by countries to implement contacttracing and leprosy PEP with SDR in the light of the WHO recommendation of SDR-PEP, this evidence-based, concrete yet flexible toolkit has been designed to servenational leprosy programme managers and support them with the practical means toLeprosy post-exposure prophylaxis toolkit357 translate policy into practice. The toolkit is freely accessible on the Infolep homepagesand updated as required: https://www.leprosy-information.org/keytopic/leprosy-post-exposure-prophylaxis-lpep-programm

Global assessment of small RNAs reveals a non-coding transcript involved in biofilm formation and attachment in <i>Acinetobacter baumannii</i> ATCC 17978

<div><p>Many strains of <i>Acinetobacter baumannii</i> have been described as being able to form biofilm. Small non-coding RNAs (sRNAs) control gene expression in many regulatory circuits in bacteria. The aim of the present work was to provide a global description of the sRNAs produced both by planktonic and biofilm-associated (sessile) cells of <i>A</i>. <i>baumannii</i> ATCC 17978, and to compare the corresponding gene expression profiles to identify sRNAs molecules associated to biofilm formation and virulence. sRNA was extracted from both planktonic and sessile cells and reverse transcribed. cDNA was subjected to 454-pyrosequencing using the GS-FLX Titanium chemistry. The global analysis of the small RNA transcriptome revealed different sRNA expression patterns in planktonic and biofilm associated cells, with some of the transcripts only expressed or repressed in sessile bacteria. A total of 255 sRNAs were detected, with 185 of them differentially expressed in the different types of cells. A total of 9 sRNAs were expressed only in biofilm cells, while the expression of other 21 coding regions were repressed only in biofilm cells. Strikingly, the expression level of the sRNA 13573 was 120 times higher in biofilms than in planktonic cells, an observation that prompted us to further investigate the biological role of this non-coding transcript. Analyses of an isogenic mutant and over-expressing strains revealed that the sRNA 13573 gene is involved in biofilm formation and attachment to A549 human alveolar epithelial cells. The present work serves as a basis for future studies examining the complex regulatory network that regulate biofilm biogenesis and attachment to eukaryotic cells in <i>A</i>. <i>baumannii</i> ATCC 17978.</p></div