Browsing by Author "Theron, A."

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    Differential inhibition of adenylylated and deadenylylated forms of M. tuberculosis glutamine synthetase as a drug discovery platform
    (Public Library of Science, 2017-03-29) Theron, A.; Roth, R. L.; Hoppe, H.; Parkinson, C.; Van Der Westhuyzen, C. W.; Stoychev, S.; Wiid, I.; Pietersen, R. D.; Baker, B.; Kenyon, C. P.
    ENGLISH ABSTRACT: Glutamine synthetase is a ubiquitous central enzyme in nitrogen metabolism that is controlled by up to four regulatory mechanisms, including adenylylation of some or all of the twelve subunits by adenylyl transferase. It is considered a potential therapeutic target for the treatment of tuberculosis, being essential for the growth of Mycobacterium tuberculosis, and is found extracellularly only in the pathogenic Mycobacterium strains. Human glutamine synthetase is not regulated by the adenylylation mechanism, so the adenylylated form of bacterial glutamine synthetase is of particular interest. Previously published reports show that, when M. tuberculosis glutamine synthetase is expressed in Escherichia coli, the E. coli adenylyl transferase does not optimally adenylylate the M. tuberculosis glutamine synthetase. Here, we demonstrate the production of soluble adenylylated M. tuberulosis glutamine synthetase in E. coli by the co-expression of M. tuberculosis glutamine synthetase and M. tuberculosis adenylyl transferase. The differential inhibition of adenylylated M. tuberulosis glutamine synthetase and deadenylylated M. tuberulosis glutamine synthetase by ATP based scaffold inhibitors are reported. Compounds selected on the basis of their enzyme inhibition were also shown to inhibit M. tuberculosis in the BACTEC 460TB™ assay as well as the intracellular inhibition of M. tuberculosis in a mouse bone-marrow derived macrophage assay.
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    Optimising perioperative care for hip and knee arthroplasty in South Africa : a Delphi consensus study
    (BioMed Central, 2018-05-09) Plenge, U.; Nortje, M. B.; Marais, L. C.; Jordaan, J. D.; Parker, R.; Van der Westhuizen, N.; Van der Merwe, J. F.; Marais, J.; September, W. V.; Davies, G. L.; Pretorius, T.; Solomon, C.; Ryan, P.; Torborg, A. M.; Farina, Z.; Smit, R.; Cairns, C.; Shanahan, H.; Sombili, S.; Mazibuko, A.; Hobbs, H. R.; Porrill, O. S.; Timothy, N. E.; Siebritz, R. E.; Van der Westhuizen, C.; Troskie, A. J.; Blake, C. A.; Gray, L. A.; Munting, T. W.; Steinhaus, H. K. S.; Rowe, P.; Van der Walt, J. G.; Isaacs Noordien, R.; Theron, A.; Biccard, B. M.
    Background: A structured approach to perioperative patient management based on an enhanced recovery pathway protocol facilitates early recovery and reduces morbidity in high income countries. However, in low- and middle-income countries (LMICs), the feasibility of implementing enhanced recovery pathways and its influence on patient outcomes is scarcely investigated. To inform similar practice in LMICs for total hip and knee arthroplasty, it is necessary to identify potential factors for inclusion in such a programme, appropriate for LMICs. Methods: Applying a Delphi method, 33 stakeholders (13 arthroplasty surgeons, 12 anaesthetists and 8 physiotherapists) from 10 state hospitals representing 4 South African provinces identified and prioritised i) risk factors associated with poor outcomes, ii) perioperative interventions to improve outcomes and iii) patient and clinical outcomes necessary to benchmark practice for patients scheduled for primary elective unilateral total hip and knee arthroplasty. Results: Thirty of the thirty-three stakeholders completed the 3 months Delphi study. The first round yielded i) 36 suggestions to preoperative risk factors, ii) 14 (preoperative), 18 (intraoperative) and 23 (postoperative) suggestions to best practices for perioperative interventions to improve outcomes and iii) 25 suggestions to important postsurgical outcomes. These items were prioritised by the group in the consecutive rounds and consensus was reached for the top ten priorities for each category. Conclusion: The consensus derived risk factors, perioperative interventions and important outcomes will inform the development of a structured, perioperative multidisciplinary enhanced patient care protocol for total hip and knee arthroplasty. It is anticipated that this study will provide the construct necessary for developing pragmatic enhanced care pathways aimed at improving patient outcomes after arthroplasty in LMICs.