A new find of Megalotragus priscus (Alcelaphini, Bovidae) from the central Karoo, South Africa

Main articleWe document the occurrence of the Florisian, or late Quaternary, form of the giant alcelaphine, Megalotragus priscus, from dongas on the Ongers River, near Britstown in the central Karoo. This is significant as it confirms the occurrence of the species in the Karoo and it suggests significantly wetter environments and productive grasslands in the central Karoo in pre-Holocene times. The present-day Karoo environment did not maintain populations of large ruminant grazers similar to M. priscus, and other specialized Florisian grazers, prior to the advent of agriculture and pasture management. Aridification in recent times is the likely cause of changes in grassland quality and the local dissappearance of these animals, if not their extinction.Non

In Vitro Pharmacological Characterization of RXFP3 Allosterism: An Example of Probe Dependency

Recent findings suggest that the relaxin-3 neural network may represent a new ascending arousal pathway able to modulate a range of neural circuits including those affecting circadian rhythm and sleep/wake states, spatial and emotional memory, motivation and reward, the response to stress, and feeding and metabolism. Therefore, the relaxin-3 receptor (RXFP3) is a potential therapeutic target for the treatment of various CNS diseases. Here we describe a novel selective RXFP3 receptor positive allosteric modulator (PAM), 3-[3,5-Bis(trifluoromethyl)phenyl]-1-(3,4-dichlorobenzyl)-1-[2-(5-methoxy-1H-indol-3-yl)ethyl]urea (135PAM1). Calcium mobilization and cAMP accumulation assays in cell lines expressing the cloned human RXFP3 receptor show the compound does not directly activate RXFP3 receptor but increases functional responses to amidated relaxin-3 or R3/I5, a chimera of the INSL5 A chain and the Relaxin-3 B chain. 135PAM1 increases calcium mobilization in the presence of relaxin-3NH2 and R3/I5NH2 with pEC50 values of 6.54 (6.46 to 6.64) and 6.07 (5.94 to 6.20), respectively. In the cAMP accumulation assay, 135PAM1 inhibits the CRE response to forskolin with a pIC50 of 6.12 (5.98 to 6.27) in the presence of a probe (10 nM) concentration of relaxin-3NH2. 135PAM1 does not compete for binding with the orthosteric radioligand, [125I] R3I5 (amide), in membranes prepared from cells expressing the cloned human RXFP3 receptor. 135PAM1 is selective for RXFP3 over RXFP4, which also responds to relaxin-3. However, when using the free acid (native) form of relaxin-3 or R3/I5, 135PAM1 doesn't activate RXFP3 indicating that the compound's effect is probe dependent. Thus one can exchange the entire A-chain of the probe peptide while retaining PAM activity, but the state of the probe's c-terminus is crucial to allosteric activity of the PAM. These data demonstrate the existence of an allosteric site for modulation of this GPCR as well as the subtlety of changes in probe molecules that can affect allosteric modulation of RXFP3

Optimising perioperative care for hip and knee arthroplasty in South Africa: a Delphi consensus study

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

A position statement and practical guide to the use of particulate filtering facepiece respirators (N95, FFP2, or equivalent) for South African health workers exposed to respiratory pathogens including Mycobacterium tuberculosis and SARS-CoV-2

Summary Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is transmitted mainly by aerosol in particles <10 µm that can remain suspended for hours before being inhaled. Because particulate filtering facepiece respirators (‘respirators’; e.g. N95 masks) are more effective than surgical masks against bio-aerosols, many international organisations now recommend that health workers (HWs) wear a respirator when caring for individuals who may have COVID-19. In South Africa (SA), however, surgical masks are still recommended for the routine care of individuals with possible or confirmed COVID-19, with respirators reserved for so-called aerosol-generating procedures. In contrast, SA guidelines do recommend respirators for routine care of individuals with possible or confirmed tuberculosis (TB), which is also transmitted via aerosol. In health facilities in SA, distinguishing between TB and COVID-19 is challenging without examination and investigation, both of which may expose HWs to potentially infectious individuals. Symptom-based triage has limited utility in defining risk. Indeed, significant proportions of individuals with COVID-19 and/or pulmonary TB may not have symptoms and/or test negative. The prevalence of undiagnosed respiratory disease is therefore likely significant in many general clinical areas (e.g. waiting areas). Moreover, a proportion of HWs are HIV-positive and are at increased risk of severe COVID-19 and death. Recommendations Sustained improvements in infection prevention and control (IPC) require reorganisation of systems to prioritise HW and patient safety. While this will take time, it is unacceptable to leave HWs exposed until such changes are made. We propose that the SA health system adopts a target of ‘zero harm’, aiming to eliminate transmission of respiratory pathogens to all individuals in every healthcare setting. Accordingly, we recommend: 1. the use of respirators by all staff (clinical and non-clinical) during activities that involve contact or sharing air in indoor spaces with individuals who: (i) have not yet been clinically evaluated; or (ii) are thought or known to have TB and/or COVID-19 or other potentially harmful respiratory infections; 2. the use of respirators that meet national and international manufacturing standards; 3. evaluation of all respirators, at the least, by qualitative fit testing; and 4. the use of respirators as part of a ‘package of care’ in line with international IPC recommendations. We recognise that this will be challenging, not least due to global and national shortages of personal protective equipment (PPE). SA national policy around respiratory protective equipment enables a robust framework for manufacture and quality control and has been supported by local manufacturers and the Department of Trade, Industry and Competition. Respirator manufacturers should explore adaptations to improve comfort and reduce barriers to communication. Structural changes are needed urgently to improve the safety of health facilities: persistent advocacy and research around potential systems change remain essential

Genetic properties of feed efficiency parameters in meat-type chickens

<p>Abstract</p> <p>Background</p> <p>Feed cost constitutes about 70% of the cost of raising broilers, but the efficiency of feed utilization has not kept up the growth potential of today's broilers. Improvement in feed efficiency would reduce the amount of feed required for growth, the production cost and the amount of nitrogenous waste. We studied residual feed intake (RFI) and feed conversion ratio (FCR) over two age periods to delineate their genetic inter-relationships.</p> <p>Methods</p> <p>We used an animal model combined with Gibb sampling to estimate genetic parameters in a pedigreed random mating broiler control population.</p> <p>Results</p> <p>Heritability of RFI and FCR was 0.42-0.45. Thus selection on RFI was expected to improve feed efficiency and subsequently reduce feed intake (FI). Whereas the genetic correlation between RFI and body weight gain (BWG) at days 28-35 was moderately positive, it was negligible at days 35-42. Therefore, the timing of selection for RFI will influence the expected response. Selection for improved RFI at days 28-35 will reduce FI, but also increase growth rate. However, selection for improved RFI at days 35-42 will reduce FI without any significant change in growth rate. The nature of the pleiotropic relationship between RFI and FCR may be dependent on age, and consequently the molecular factors that govern RFI and FCR may also depend on stage of development, or on the nature of resource allocation of FI above maintenance directed towards protein accretion and fat deposition. The insignificant genetic correlation between RFI and BWG at days 35-42 demonstrates the independence of RFI on the level of production, thereby making it possible to study the molecular, physiological and nutrient digestibility mechanisms underlying RFI without the confounding effects of growth. The heritability estimate of FCR was 0.49 and 0.41 for days 28-35 and days 35-42, respectively.</p> <p>Conclusion</p> <p>Selection for FCR will improve efficiency of feed utilization but because of the genetic dependence of FCR and its components, selection based on FCR will reduce FI and increase growth rate. However, the correlated responses in both FI and BWG cannot be predicted accurately because of the inherent problem of FCR being a ratio trait.</p

Genetic Diversity and Population Structure of Saccharomyces cerevisiae Strains Isolated from Different Grape Varieties and Winemaking Regions

We herein evaluate intraspecific genetic diversity of fermentative vineyard-associated S. cerevisiae strains and evaluate relationships between grape varieties and geographical location on populational structures. From the musts obtained from 288 grape samples, collected from two wine regions (16 vineyards, nine grape varieties), 94 spontaneous fermentations were concluded and 2820 yeast isolates were obtained that belonged mainly (92%) to the species S. cerevisiae. Isolates were classified in 321 strains by the use of ten microsatellite markers. A high strain diversity (8–43 strains per fermentation) was associated with high percentage (60–100%) of fermenting samples per vineyard, whereas a lower percentage of spontaneous fermentations (0–40%) corresponded to a rather low strain diversity (1–10 strains per fermentation)

Neuromuscular disease genetics in under-represented populations: increasing data diversity

\ua9 The Author(s) 2023. Published by Oxford University Press on behalf of the Guarantors of Brain. Neuromuscular diseases (NMDs) affect ∼15 million people globally. In high income settings DNA-based diagnosis has transformed care pathways and led to gene-specific therapies. However, most affected families are in low-to-middle income countries (LMICs) with limited access to DNA-based diagnosis. Most (86%) published genetic data is derived from European ancestry. This marked genetic data inequality hampers understanding of genetic diversity and hinders accurate genetic diagnosis in all income settings. We developed a cloud-based transcontinental partnership to build diverse, deeply-phenotyped and genetically characterized cohorts to improve genetic architecture knowledge, and potentially advance diagnosis and clinical management. We connected 18 centres in Brazil, India, South Africa, Turkey, Zambia, Netherlands and the UK. We co-developed a cloud-based data solution and trained 17 international neurology fellows in clinical genomic data interpretation. Single gene and whole exome data were analysed via a bespoke bioinformatics pipeline and reviewed alongside clinical and phenotypic data in global webinars to inform genetic outcome decisions. We recruited 6001 participants in the first 43 months. Initial genetic analyses \u27solved\u27 or \u27possibly solved\u27 ∼56% probands overall. In-depth genetic data review of the four commonest clinical categories (limb girdle muscular dystrophy, inherited peripheral neuropathies, congenital myopathy/muscular dystrophies and Duchenne/Becker muscular dystrophy) delivered a ∼59% \u27solved\u27 and ∼13% \u27possibly solved\u27 outcome. Almost 29% of disease causing variants were novel, increasing diverse pathogenic variant knowledge. Unsolved participants represent a new discovery cohort. The dataset provides a large resource from under-represented populations for genetic and translational research. In conclusion, we established a remote transcontinental partnership to assess genetic architecture of NMDs across diverse populations. It supported DNA-based diagnosis, potentially enabling genetic counselling, care pathways and eligibility for gene-specific trials. Similar virtual partnerships could be adopted by other areas of global genomic neurological practice to reduce genetic data inequality and benefit patients globally

Molecular basis of association of receptor activity-modifying protein 3 with the family B G protein-coupled secretin receptor

The three receptor activity-modifying proteins (RAMPs) have been recognized as being important for the trafficking and function of a subset of family B G protein-coupled receptors, although the structural basis for this has not been well established. In the current work, we use morphological fluorescence techniques, bioluminescence resonance energy transfer, and bimolecular fluorescence complementation to demonstrate that the secretin receptor associates specifically with RAMP3, but not with RAMP1 or RAMP2. We use truncation constructs, peptide competition experiments, and chimeric secretin-GLP1 receptor constructs to establish that this association is structurally specific, dependent on the intramembranous region of the RAMP and TM6 and TM7 of this receptor. There were no observed changes in secretin-stimulated cAMP, intracellular calcium, ERK1/2 phosphorylation, or receptor internalization in receptor-bearing COS or CHO-K1 cells in the presence or absence of exogenous RAMP transfection, although the secretin receptor trafficks normally to the cell surface in these cells in a RAMP-independent manner, resulting in both free and RAMP-associated receptor on the cell surface. RAMP3 association with this receptor was shown to be capable of rescuing a receptor mutant (G241C) that is normally trapped intracellularly in the biosynthetic machinery. Similarly, secretin receptor expression had functional effects on adrenomedullin activity, with increasing secretin receptor expression competing for RAMP3 association with the calcitonin receptor-like receptor to yield a functional adrenomedullin receptor. These data provide important new insights into the structural basis for RAMP3 interaction with a family B G protein-coupled receptor, potentially providing a highly selective target for drug action. This may be representative of similar interactions between other members of this receptor family and RAMP proteins

Impedance Responses Reveal β2-Adrenergic Receptor Signaling Pluridimensionality and Allow Classification of Ligands with Distinct Signaling Profiles

The discovery that drugs targeting a single G protein-coupled receptor (GPCR) can differentially modulate distinct subsets of the receptor signaling repertoire has created a challenge for drug discovery at these important therapeutic targets. Here, we demonstrate that a single label-free assay based on cellular impedance provides a real-time integration of multiple signaling events engaged upon GPCR activation. Stimulation of the β2-adrenergic receptor (β2AR) in living cells with the prototypical agonist isoproterenol generated a complex, multi-featured impedance response over time. Selective pharmacological inhibition of specific arms of the β2AR signaling network revealed the differential contribution of Gs-, Gi- and Gβγ-dependent signaling events, including activation of the canonical cAMP and ERK1/2 pathways, to specific components of the impedance response. Further dissection revealed the essential role of intracellular Ca2+ in the impedance response and led to the discovery of a novel β2AR-promoted Ca2+ mobilization event. Recognizing that impedance responses provide an integrative assessment of ligand activity, we screened a collection of β-adrenergic ligands to determine if differences in the signaling repertoire engaged by compounds would lead to distinct impedance signatures. An unsupervised clustering analysis of the impedance responses revealed the existence of 5 distinct compound classes, revealing a richer signaling texture than previously recognized for this receptor. Taken together, these data indicate that the pluridimensionality of GPCR signaling can be captured using integrative approaches to provide a comprehensive readout of drug activity