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Background. Optimal theatre utilisation is essential to reduce long waiting lists for elective surgeries and to increase cost-effective theatre operation. Utilisation rates well below the global benchmark of 80% have been reported for government hospitals in Johannesburg, South Africa (SA). Objective. To investigate utilisation of three paediatric theatres at the Chris Hani Baragwanath Academic Hospital (CHBAH) in Johannesburg. Methods. Surgery lists of the three theatres were reviewed for three one-week periods over a four-month study period. Preoperative, intraoperative and postoperative data were collected to create a timeline for each theatre and each surgical case, including reasons for cancellations, delays or expedited times. Results. A total of 152 surgeries were scheduled during the reviewed study period, of which 44 cases were cancelled. The utilisation rate was 59.8% across the three theatres combined, with individual rates calculated as 62.7%, 58.2% and 57.0% in the burns, general and neonatal theatres, respectively. The primary factor contributing to under-utilisation was early completion of the scheduled list. Surgery delays were mainly due to delays in transferring the patient to the theatre and between anaesthetic induction and the start of surgery. Conclusion. Utilisation of the paediatric theatres at CHBAH is below the ideal benchmark of 80%; however, utilisation was better than expected when compared with findings from other public-sector hospitals in SA. However, theatre efficiency was found to be very low and perhaps better explains the reasons for backlogs in paediatric surgeries at CHBAH. [ABSTRACT FROM AUTHOR]

The identification of the coproporphyrin-dependent heme biosynthetic pathway, which is used almost exclusively by monoderm bacteria in 2015 by Dailey et al. triggered studies aimed at investigating the enzymes involved in this pathway that were originally assigned to the protoporphyrin-dependent heme biosynthetic pathway. Here, we revisit the active site of coproporphyrin ferrochelatase by a biophysical and biochemical investigation using the physiological substrate coproporphyrin III, which in contrast to the previously used substrate protoporphyrin IX has four propionate substituents and no vinyl groups. In particular, we have compared the reactivity of wild-type coproporphyrin ferrochelatase from the firmicute Listeria monocytogenes with those of variants, namely, His182Ala (H182A) and Glu263Gln (E263Q), involving two key active site residues. Interestingly, both variants are active only toward the physiological substrate coproporphyrin III but inactive toward protoporphyrin IX. In addition, E263 exchange impairs the final oxidation step from ferrous coproheme to ferric coproheme. The characteristics of the active site in the context of the residues involved and the substrate binding properties are discussed here using structural and functional means, providing a further contribution to the deciphering of this enigmatic reaction mechanism., (© 2024 The Authors. The FEBS Journal published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)

Objective: The aim of this study was to assess the efficacy of physical therapist interventions on the intensity, frequency, and duration of headaches, as well as on the quality of life of patients with cervicogenic headache., Methods: The following databases were searched up to October 2022: Physiotherapy Evidence Database, Web of Science, Pubmed, and Cochrane Library. Randomized controlled trials assessing the effect of physical therapist interventions on adults with cervicogenic headache were included. Quality appraisal was conducted using the Cochrane risk of bias 2.0 tool and the Confidence in Network Meta-analysis web app. Synthesis methods were conducted in accordance with the Cochrane Handbook., Results: Of the 28 identified reports, 23 were included in the quantitative synthesis. Manipulation plus dry needling was the highest-ranked intervention to reduce the short-term headache intensity (mean difference [MD] = -4.87; 95% CI = -8.51 to -1.24) and frequency (MD = -3.09; 95% CI = -4.93 to -1.25) when compared to a control intervention. Other high-ranked and clinically effective interventions (when compared to a control intervention) were muscle-energy technique plus exercise (MD = 4.37; 95% CI = -8.01 to -0.74), as well as soft tissue techniques plus exercise (MD = -3.01; 95% CI = -5.1 to -0.92) to reduce short-term headache intensity, and dry needling plus exercise (MD = -2.92; 95% CI = -4.73 to -1.11) to reduce short-term headache frequency. These results were based on a low certainty of evidence., Conclusion: The 4 most highly ranked interventions can be considered in clinical practice. However, no conclusive recommendation can be made due to the low certainty of evidence., Impact: Combined interventions such as spinal joint manipulation plus dry needling and muscle-energy technique or soft tissue techniques or dry needling plus exercises seem to be the best interventions to reduce short-term cervicogenic headache intensity and/or frequency., (© The Author(s) 2023. Published by Oxford University Press on behalf of the American Physical Therapy Association. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Coproporphyrinogen oxidase (CgoX) and protoporphyrinogen oxidase (PgoX) catalyze the oxidation of the flexible cyclic tetrapyrrole of porphyrinogen compounds into fully conjugated, planar macrocyclic porphyrin compounds during heme biosynthesis. These enzymes are activated via different pathways. CgoX oxidizes coproporphyrinogen III to coproporphyrin III in the coproporphyrin-dependent pathway, whereas PgoX oxidizes protoporphyrinogen IX to protoporphyrin IX in the penultimate step of the protoporphyrin-dependent pathway. The phylogenetic analysis presented herein demonstrates a clear differentiation between the two enzyme classes, as evidenced by the clustering of sequences in distinct clades, and it shows that, at the origin of porphyrinogen-type oxidase evolution, PgoXs from cyanobacteria were found, which were noticeably separated from descendant PgoX representatives of Deltaproteobacteria and all later PgoX variants, leading to many eukaryotic clades. CgoX sequences originating from the monoderm Actinomycetota and Bacillota were well separated from the predecessor clades containing PgoX types and represent a peculiar type of gene speciation. The structural similarities and differences between these two oxidases are discussed based on their protein sequence alignment and a structural comparison.

Understanding the reaction mechanism of enzymes at the molecular level is generally a difficult task, since many parameters affect the turnover. Often, due to high reactivity and formation of transient species or intermediates, detailed information on enzymatic catalysis is obtained by means of model substrates. Whenever possible, it is essential to confirm a reaction mechanism based on substrate analogues or model systems by using the physiological substrates. Here we disclose the ferrous iron incorporation mechanism, in solution, and in crystallo, by the coproporphyrin III-coproporphyrin ferrochelatase complex from the firmicute, pathogen, and antibiotic resistant, Listeria monocytogenes. Coproporphyrin ferrochelatase plays an important physiological role as the metalation represents the penultimate reaction step in the prokaryotic coproporphyrin-dependent heme biosynthetic pathway, yielding coproheme (ferric coproporphyrin III). By following the metal titration with resonance Raman spectroscopy and x-ray crystallography, we prove that upon metalation the saddling distortion becomes predominant both in the crystal and in solution. This is a consequence of the readjustment of hydrogen bond interactions of the propionates with the protein scaffold during the enzymatic catalysis. Once the propionates have established the interactions typical of the coproheme complex, the distortion slowly decreases, to reach the almost planar final product., (© 2023 The Authors. Protein Science published by Wiley Periodicals LLC on behalf of The Protein Society.)

The coproporphyrin dependent heme biosynthesis pathway is almost exclusively utilized by Gram-positive bacteria. This fact makes it a worthwhile topic for basic research, since a fundamental understanding of a metabolic pathway is necessary to translate the focus towards medical biotechnology, which is very relevant in this specific case, considering the need for new antibiotic targets to counteract the pathogenicity of Gram-positive superbugs. Over the years a lot of structural data on the set of enzymes acting in Gram-positive heme biosynthesis has accumulated in the Protein Database (www.pdb.org). One major challenge is to filter and analyze all available structural information in sufficient detail in order to be helpful and to draw conclusions. Here we pursued to give a holistic overview of structural information on enzymes involved in the coproporphyrin dependent heme biosynthesis pathway. There are many aspects to be extracted from experimentally determined structures regarding the reaction mechanisms, where the smallest variation of the position of an amino acid residue might be important, but also on a larger level regarding protein-protein interactions, where the focus has to be on surface characteristics and subunit (secondary) structural elements and oligomerization. This review delivers a status quo, highlights still missing information, and formulates future research endeavors in order to better understand prokaryotic heme biosynthesis., Competing Interests: The authors of the submitted manuscript “Structural aspects of enzymes involved in prokaryotic Gram-positive heme biosynthesis” declare no conflict of interests., (© 2023 The Authors.)

Accurate and fast detection of viruses is crucial for controlling outbreaks of many diseases; therefore, to date, numerous sensing systems for their detection have been studied. On top of the performance of these sensing systems, the availability of biorecognition elements specific to especially the new etiological agents is an additional fundamental challenge. Therefore, besides high sensitivity and selectivity, such advantages as the size of the sensor and possibly low volume of analyzed samples are also important, especially at the stage of evaluating the receptor-target interactions in the case of new etiological agents when typically, only tiny amounts of the receptor are available for testing. This work introduces a real-time, highly miniaturized sensing solution based on microcavity in-line Mach-Zehnder interferometer (μIMZI) induced in optical fiber for SARS-CoV-2 virus-like particles detection. The assay is designed to detect conserved regions of the SARS-CoV-2 viral particles in a sample with a volume as small as hundreds of picoliters, reaching the detection limit at the single ng per mL level., (© 2023. The Author(s).)

Coproporphyrin ferrochelatases (CpfCs) are enzymes catalyzing the penultimate step in the coproporphyrin-dependent (CPD) heme biosynthesis pathway, which is mainly utilized by monoderm bacteria. Ferrochelatases insert ferrous iron into a porphyrin macrocycle and have been studied for many decades, nevertheless many mechanistic questions remain unanswered to date. Especially CpfCs, which are found in the CPD pathway, are currently in the spotlight of research. This pathway was identified in 2015 and revealed that the correct substrate for these ferrochelatases is coproporphyrin III (cpIII) instead of protoporphyrin IX, as believed prior the discovery of the CPD pathway. The chemistry of cpIII, which has four propionates, differs significantly from protoporphyrin IX, which features two propionate and two vinyl groups. These findings let us to thoroughly describe the physiological cpIII-ferrochelatase complex in solution and in the crystal phase. Here, we present the first crystallographic structure of the CpfC from the representative monoderm pathogen Listeria monocytogenes bound to its physiological substrate, cpIII, together with the in-solution data obtained by resonance Raman and UV-vis spectroscopy, for wild-type ferrochelatase and variants, analyzing propionate interactions. The results allow us to evaluate the porphyrin distortion and provide an in-depth characterization of the catalytically-relevant binding mode of cpIII prior to iron insertion. Our findings are discussed in the light of the observed structural restraints and necessities for this porphyrin-enzyme complex to catalyze the iron insertion process. Knowledge about this initial situation is essential for understanding the preconditions for iron insertion in CpfCs and builds the basis for future studies., (© 2022 The Authors. Protein Science published by Wiley Periodicals LLC on behalf of The Protein Society.)

Monitoring cell adhesion and growth are crucial for various applications involving drug screening, cytotoxicity, and cytocompatibility studies. However, acquiring accurate information about the growing state and responsiveness to a treatment of a cell system in a real-time and label-free manner is still a challenge. This work presents the first research on direct, real-time, and label-free adherent cell culture monitoring using a microcavity in-line Mach-Zehnder interferometer (μIMZI) fabricated in an optical fiber. The sensing solution based on μIMZI offers a great advantage over many other monitoring concepts tracking the changes taking place on the microcavity's bottom surface and within its volume, thus offering a greater penetration depth. In this study, we verified performance of the approach using a non-cancer bone marrow stromal cell line HS-5. The results demonstrate that the changes of the acquired signal are closely related to the different states of cells' adhesion, proliferation, morphology, and variation of mass. Thus, this label-free, real-time μIMZI-based monitoring technique gives a great promise to the analysis or monitoring of relevant new treatments in future scientific, as well as clinical applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier B.V.)

We report an optical parametric amplifier (OPA), providing a maximum pulse energy of ∼200 µJ at 700-950 nm and a pulse duration of ∼1 ps. The OPA is driven by a ∼1 ps pulse with ∼2.5 mJ energy at 1 kHz, provided by a commercial thin-disk based laser. Using the output pulse of the OPA as pump, the thin-disk laser pulses at 1030 nm as Stokes, and the second harmonic (515 nm) as probe, we investigate the coherent anti-Stokes Raman scattering (CARS) of N 2 and CO 2 at various temperatures.

Coproporpyhrin III is the substrate of coproporphyrin ferrochelatases (CpfCs). These enzymes catalyse the insertion of ferrous iron into the porphyrin ring. This is the penultimate step within the coproporphyrin-dependent haeme biosynthesis pathway. This pathway was discovered in 2015 and is mainly utilised by monoderm bacteria. Prior to this discovery, monoderm bacteria were believed to utilise the protoporphyrin-dependent pathway, analogously to diderm bacteria, where the substrate for the respective ferrochelatase is protoporphyrin IX, which has two propionate groups at positions 6 and 7 and two vinyl groups at positions 2 and 4. In this work, we describe for the first time the interactions of the four-propionate substrate, coproporphyrin III, and the four-propionate product, iron coproporphyrin III (coproheme), with the CpfC from Listeria monocytogenes and pin down differences with respect to the protoporphyrin IX and haeme b complexes in the wild-type (WT) enzyme. We further created seven LmCpfC variants aiming at altering substrate and product coordination. The WT enzyme and all the variants were comparatively studied by spectroscopic, thermodynamic and kinetic means to investigate in detail the H-bonding interactions, which govern complex stability and substrate specificity. We identified a tyrosine residue (Y124 in LmCpfC), coordinating the propionate at position 2, which is conserved in monoderm CpfCs, to be highly important for binding and stabilisation. Importantly, we also describe a tyrosine-serine-threonine triad, which coordinates the propionate at position 4. The study of the triad variants indicates structural differences between the coproporphyrin III and the coproheme complexes. ENZYME: EC 4.99.1.9., (© 2021 The Authors. The FEBS Journal published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)

Context: Revised Trauma Score (RTS) is a validated tool in assessing patients in a pre-hospital setting. There are limited data describing its potential use in guiding referral to intensive care., Aims: Trauma scoring systems require appropriate validation in a local setting before effective application. This work examines the applicability of RTS to a paediatric intensive care trauma population., Settings and Design: A retrospective record review of trauma patients admitted to the paediatric intensive care unit at Chris Hani Baragwanath Academic Hospital between 2011 and 2013 was performed., Subjects and Methods: The cohort was arbitrarily split into three subgroups based on RTS using the 33 rd and 66 th percentile values and groups compared. Outcome measures examined included mortality, age, gender, length of stay (LoS), duration of ventilation (DoV) and change in Glasgow Coma Scale (GCS) from admission to discharge., Statistical Analysis Used: Categorical values examined with Fisher's exact test. Non-categorical values examined with the Kruskal-Wallis and Dunn's multiple comparisons tests., Results: Of 919 children admitted, 165 admissions were secondary to trauma. Data necessary for calculation of RTS were available in 91 patients. The mean RTS was 5.3, 33 rd percentile was 4.7 and 66 th was 5.9. DoV (P = 0.0104) and LoS (P = 0.0395) were significantly different between intermediate- and low-risk groups as was change in GCS between low-risk and both other groups (P < 0.0001)., Conclusions: RTS is not predictive of mortality between high-risk (RTS < 4.09) and low-risk patients (RTS > 5.67) in this population. It may be useful in predicting other outcomes such as DoV and LoS., Competing Interests: None

Since the advent of protein crystallography, atomic-level macromolecular structures have provided a basis to understand biological function. Enzymologists use detailed structural insights on ligand coordination, interatomic distances, and positioning of catalytic amino acids to rationalize the underlying electronic reaction mechanisms. Often the proteins in question catalyze redox reactions using metal cofactors that are explicitly intertwined with their function. In these cases, the exact nature of the coordination sphere and the oxidation state of the metal is of utmost importance. Unfortunately, the redox-active nature of metal cofactors makes them especially susceptible to photoreduction, meaning that information obtained by photoreducing X-ray sources about the environment of the cofactor is the least trustworthy part of the structure. In this work we directly compare the kinetics of photoreduction of six different heme protein crystal species by X-ray radiation. We show that a dose of ∼40 kilograys already yields 50% ferrous iron in a heme protein crystal. We also demonstrate that the kinetics of photoreduction are completely independent from variables unique to the different samples tested. The photoreduction-induced structural rearrangements around the metal cofactors have to be considered when biochemical data of ferric proteins are rationalized by constraints derived from crystal structures of reduced enzymes., Competing Interests: Conflict of interest—The authors declare that they have no conflicts of interest with the contents of this article., (© 2020 Pfanzagl et al.)

Increasing numbers of HIV/AIDS-infected individuals have presented to medical casualty at Charlotte Maxeke Johannesburg Academic Hospital (CMJAH) after attempting suicide by overdosing on their antiretroviral therapy. Since 2009, medical gastro-enterology at CMJAH has been the primary specialty unit for cases of accidental or intentional overdose. Psychiatry and other medical sub-specialties are consulted as needed. Our unit sees approximately 1 case a month of accidental/intentional overdose with antiretrovirals. Between January and September 2010, 6% of all overdoses seen at CMJAH were of antiretroviral origin. Supportive care is provided and patients undergo psychiatric evaluation. The information available on overdoses with antiretrovirals is from studies in developed countries, where intravenous drug users and men who have sex with men make up the bulk of the HIV-positive population. This differs significantly from South Africa, which now has the largest antiretroviral programme in the world. With little evidence related to this type of overdose, are we approaching the management, monitoring and follow-up of these patients correctly?