Neurite Development and Repair in Worms and Flies.

How the nervous system is wired has been a central question of neuroscience since the inception of the field, and many of the foundational discoveries and conceptual advances have been made through the study of invertebrate experimental organisms, including Caenorhabditis elegans and Drosophila melanogaster. Although many guidance molecules and receptors have been identified, recent experiments have shed light on the many modes of action for these pathways. Here, we summarize the recent progress in determining how the physical and temporal constraints of the surrounding environment provide instructive regulations in nervous system wiring. We use Netrin and its receptors as an example to analyze the complexity of how they guide neurite outgrowth. In neurite repair, conserved injury detection and response-signaling pathways regulate gene expression and cytoskeletal dynamics. We also describe recent developments in the research on molecular mechanisms of neurite regeneration in worms and flies.

Anti-Cholestatic Therapy with Obeticholic Acid Improves Short-Term Memory in Bile Duct-Ligated Mice.

Patients with cholestatic liver disease, including those with primary biliary cholangitis, can experience symptoms of impaired cognition or brain fog. This phenomenon remains unexplained and is currently untreatable. Bile duct ligation (BDL) is an established rodent model of cholestasis. In addition to liver changes, BDL animals develop cognitive symptoms early in the disease process (before development of cirrhosis and/or liver failure). The cellular mechanisms underpinning these cognitive symptoms are poorly understood. Herein, the study explored the neurocognitive symptom manifestations, and tested potential therapies, in BDL mice, and used human neuronal cell cultures to explore translatability to humans. BDL animals exhibited short-term memory loss and showed reduced astrocyte coverage of the blood-brain barrier, destabilized hippocampal network activity, and neuronal senescence. Ursodeoxycholic acid (first-line therapy for most human cholestatic diseases) did not reverse symptomatic or mechanistic aspects. In contrast, obeticholic acid (OCA), a farnesoid X receptor agonist and second-line anti-cholestatic agent, normalized memory function, suppressed blood-brain barrier changes, prevented hippocampal network deficits, and reversed neuronal senescence. Co-culture of human neuronal cells with either BDL or human cholestatic patient serum induced cellular senescence and increased mitochondrial respiration, changes that were limited again by OCA. These findings provide new insights into the mechanism of cognitive symptoms in BDL animals, suggesting that OCA therapy or farnesoid X receptor agonism could be used to limit cholestasis-induced neuronal senescence.

Internal Medicine Resident Addiction Training at the Veteran's Health Administration: A Qualitative Evaluation of Site Directors' Response to the 2022 ACGME Requirements.

BACKGROUND: Substance use disorders (SUDs) are prevalent in the USA yet remain dramatically undertreated. To address this care gap, the Accreditation Council for Graduate Medical Education (ACGME) approved revisions to the Program Requirements for Graduate Medical Education (GME) in Internal Medicine, effective July 1, 2022, requiring addiction medicine training for all internal medicine (IM) residents. The Veterans Health Administration (VHA) is a clinical training site for many academic institutions that sponsor IM residencies. This focus group project evaluated VHA IM residency site directors' perspectives about providing addiction medical education within VHA IM training sites. OBJECTIVE: To better understand the current state, barriers to, and facilitators of IM resident addiction medicine training at VHA sites. DESIGN: This was a qualitative evaluation based on semi-structured video-based focus groups. PARTICIPANTS: Participants were VHA IM site directors based at a VHA hospital or clinic throughout the USA. APPROACH: Focus groups were conducted using a semi-structured group interview guide. Two investigators coded each focus group independently, then met to create a final adjudicated coding scheme. Thematic analysis was used to identify key themes. KEY RESULTS: Forty-three participants from 38 VHA sites participated in four focus groups (average size: 11 participants). Six themes were identified within four pre-defined categories. Current state of training: most VHA sites offered no formal training in addiction medicine for IM residents. Barriers: addiction experts are often located outside of IM settings, and ACGME requirements were non-specific. Facilitators: clinical champions help support addiction training. Desired next steps: participants desired incentives to train or hire local champions and a pre-packaged didactic curriculum. CONCLUSIONS: Developing competent clinical champions and leveraging VHA addiction specialists from non-IM settings would create more addiction training opportunities for IM trainees at VHA sites. These insights can likely be applied to IM training at non-VHA sites.

Structural mechanisms of selectivity and gating in anion channelrhodopsins.

Both designed and natural anion-conducting channelrhodopsins (dACRs and nACRs, respectively) have been widely applied in optogenetics (enabling selective inhibition of target-cell activity during animal behaviour studies), but each class exhibits performance limitations, underscoring trade-offs in channel structure-function relationships. Therefore, molecular and structural insights into dACRs and nACRs will be critical not only for understanding the fundamental mechanisms of these light-gated anion channels, but also to create next-generation optogenetic tools. Here we report crystal structures of the dACR iC++, along with spectroscopic, electrophysiological and computational analyses that provide unexpected insights into pH dependence, substrate recognition, channel gating and ion selectivity of both dACRs and nACRs. These results enabled us to create an anion-conducting channelrhodopsin integrating the key features of large photocurrent and fast kinetics alongside exclusive anion selectivity.

Upcycling the anthracyclines: New mechanisms of action, toxicology, and pharmacology.

The anthracyclines are a family of natural products isolated from soil bacteria with over 2000 chemical representatives. Since their discovery seventy years ago by Waksman and co-workers, anthracyclines have become one of the best-characterized anticancer chemotherapies in clinical use. The anthracyclines exhibit broad-spectrum antineoplastic activity for the treatment of a variety of solid and liquid tumors, however, their clinical use is limited by their dose-limiting cardiotoxicity. In this review article, we discuss the toxicity of the anthracyclines on several organ systems, including new insights into doxorubicin-induced cardiotoxicity. In addition, we discuss new medicinal chemistry developments in the biosynthesis of new anthracycline analogs and the synthesis of new anthracycline analogs with diminished cardiotoxicity. Lastly, we review new studies that describe the repurposing of the anthracyclines, or "upcycling" of the anthracyclines, as anti-infective agents, or drugs for niche indications. Altogether, the anthracyclines remain a mainstay in the clinic with a potential new "lease on life" due to deeper insight into the mechanism underlying their cardiotoxicity and new developments into potential new clinical indications for their use. Keywords: Anthracycline, chemotherapy, toxicology, medicinal chemistry, biosynthesis.

A hormone receptor pathway cell-autonomously delays neuron morphological aging by suppressing endocytosis.

Neurons have a lifespan that parallels that of the organism and are largely irreplaceable. Their unusually long lifespan predisposes neurons to neurodegenerative disease. We sought to identify physiological mechanisms that delay neuron aging in Caenorhabditis elegans by asking how neuron morphological aging is arrested in the long-lived, alternate organismal state, the dauer diapause. We find that a hormone signaling pathway, the abnormal DAuer Formation (DAF) 12 nuclear hormone receptor (NHR) pathway, functions cell-intrinsically in the dauer diapause to arrest neuron morphological aging, and that same pathway can be cell-autonomously manipulated during normal organismal aging to delay neuron morphological aging. This delayed aging is mediated by suppressing constitutive endocytosis, which alters the subcellular localization of the actin regulator T cell lymphoma Invasion And Metastasis 1 (TIAM-1), thereby decreasing age-dependent neurite growth. Intriguingly, we show that suppressed endocytosis appears to be a general feature of cells in diapause, suggestive that this may be a mechanism to halt the growth and other age-related programs supported by most endosome recycling.

Longitudinal Serological Analysis and Neutralizing Antibody Levels in Coronavirus Disease 2019 Convalescent Patients.

BACKGROUND: Understanding the longitudinal trajectory of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies is crucial for diagnosis of prior infection and predicting future immunity. METHODS: We conducted a longitudinal analysis of coronavirus disease 2019 convalescent patients, with neutralizing antibody assays and SARS-CoV-2 serological assay platforms using SARS-CoV-2 spike (S) or nucleocapsid (N) antigens. RESULTS: Sensitivities of serological assays in diagnosing prior SARS-CoV-2 infection changed with time. One widely used commercial platform that had an initial sensitivity of >95% declined to 71% at 81-100 days after diagnosis. The trajectories of median binding antibody titers measured over approximately 3-4 months were not dependent on the use of SARS-CoV-2 N or S proteins as antigen. The median neutralization titer decreased by approximately 45% per month. Each serological assay gave quantitative antibody titers that were correlated with SARS-CoV-2 neutralization titers, but S-based serological assay measurements better predicted neutralization potency. Correlation between S-binding and neutralization titers deteriorated with time, and decreases in neutralization titers were not predicted by changes in S-binding antibody titers. CONCLUSIONS: Different SARS-CoV-2 serological assays are more or less well suited for surveillance versus prediction of serum neutralization potency. Extended follow-up should facilitate the establishment of appropriate serological correlates of protection against SARS-CoV-2 reinfection.

Mutations in Nonessential eIF3k and eIF3l Genes Confer Lifespan Extension and Enhanced Resistance to ER Stress in Caenorhabditis elegans.

The translation initiation factor eIF3 is a multi-subunit protein complex that coordinates the assembly of the 43S pre-initiation complex in eukaryotes. Prior studies have demonstrated that not all subunits of eIF3 are essential for the initiation of translation, suggesting that some subunits may serve regulatory roles. Here, we show that loss-of-function mutations in the genes encoding the conserved eIF3k and eIF3l subunits of the translation initiation complex eIF3 result in a 40% extension in lifespan and enhanced resistance to endoplasmic reticulum (ER) stress in Caenorhabditis elegans. In contrast to previously described mutations in genes encoding translation initiation components that confer lifespan extension in C. elegans, loss-of-function mutations in eif-3.K or eif-3.L are viable, and mutants show normal rates of growth and development, and have wild-type levels of bulk protein synthesis. Lifespan extension resulting from EIF-3.K or EIF-3.L deficiency is suppressed by a mutation in the Forkhead family transcription factor DAF-16. Mutations in eif-3.K or eif-3.L also confer enhanced resistance to ER stress, independent of IRE-1-XBP-1, ATF-6, and PEK-1, and independent of DAF-16. Our data suggest a pivotal functional role for conserved eIF3k and eIF3l accessory subunits of eIF3 in the regulation of cellular and organismal responses to ER stress and aging.

Particulate emission rates for open surfaces in Australian open cut black coal mines.

Accurate estimation of particulate emissions is fundamental to assessing the air quality risks posed by existing and proposed open cut black coal mines. The currently available emission estimation techniques are based on a limited range of empirical studies, and the need for additional research and development of activity and region specific particulate emission estimation methods has been recognised. This paper presents the results of empirical testing of particulate emission rates for open area surfaces in open cut black coal mines in three Australian regions. The emission rates are provided for specific wind speeds, thus allowing adjustment of emission rates for prevailing meteorology in these regions. The influence of surface watering as a control technique is also considered. Particulate emission rates are presented for a range of coal mining sources, and for specific wind speeds. Comparison of the emission rates with the existing published research confirms the emission rates are consistent with current approaches. This research significantly expands our current understanding by presenting emission rates for a range of open area sources, for specific wind speeds and surface watering controls. This more detailed emission estimation dataset provides for adjustments to default particulate emission rates to allow site specific data to be integrated into emissions estimation. This will result in more accurate emissions estimates for existing and future projects and reduce the potential for significant over- or under-estimation of particulate emissions from surface sources in open cut coal mines.

Variation within Lactuca spp. for Resistance to Impatiens necrotic spot virus.

Lettuce (Lactuca sativa L.) production in coastal California, one of the major lettuce-producing areas of the United States, is regularly affected by outbreaks of Impatiens necrotic spot virus (INSV), a member of the genus Orthotospovirus. Transmission of INSV among lettuce crops in this growing region has been attributed predominantly to the western flower thrips (Frankliniella occidentalis). INSV is acquired by first- or second-instar thrips nymphs feeding on infected host plants (not necessarily lettuce). The virus replicates within the insect vector, and is transmitted to new plants by adult thrips as they feed on epidermal and mesophyll cells of susceptible host plants. All currently grown cultivars of lettuce are susceptible to the disease. Screening lettuce for resistance to INSV under field conditions is problematic because natural infections appear sporadically and the virus is not evenly distributed across infected fields. We have developed a greenhouse-based assay that uses viruliferous thrips in combination with mechanical inoculation that allows dependable, year-round screening for resistance. In all, 89 cultivars, breeding lines, and plant introductions of cultivated lettuce, together with 53 accessions from 11 other Lactuca spp., 4 accessions from two dandelion (Taraxacum) species, and 4 tomato (Solanum lycopersicum L.) lines were evaluated for resistance to INSV. All tested material was susceptible to INSV to varying degrees, with the exception of two tomato lines that carry the Sw-5 gene that confers resistance to Tomato spotted wilt virus, a virus closely related to INSV. In cultivated lettuce, a partial resistance to INSV was observed in cultivars Amazona, Ancora, Antigua, Commodore, Eruption, Iceberg, La Brillante, Merlot, Telluride, and Tinto. Limited comparison of the greenhouse-based screening results with the data from opportunistic evaluations of resistance on 775 lettuce accessions from six field trials indicates consistency of results from both greenhouse and field environments. The most resistant lettuce accessions are being incorporated into our breeding program for introgression of resistance into lettuce breeding lines.

An essential role for XBP-1 in host protection against immune activation in C. elegans.

The detection and compensatory response to the accumulation of unfolded proteins in the endoplasmic reticulum (ER), termed the unfolded protein response (UPR), represents a conserved cellular homeostatic mechanism with important roles in normal development and in the pathogenesis of disease. The IRE1-XBP1/Hac1 pathway is a major branch of the UPR that has been conserved from yeast to human. X-box binding protein 1 (XBP1) is required for the differentiation of the highly secretory plasma cells of the mammalian adaptive immune system, but recent work also points to reciprocal interactions between the UPR and other aspects of immunity and inflammation. We have been studying innate immunity in the nematode Caenorhabditis elegans, having established a principal role for a conserved PMK-1 p38 mitogen-activated protein kinase (MAPK) pathway in mediating resistance to microbial pathogens. Here we show that during C. elegans development, XBP-1 has an essential role in protecting the host during activation of innate immunity. Activation of the PMK-1-mediated response to infection with Pseudomonas aeruginosa induces the XBP-1-dependent UPR. Whereas a loss-of-function xbp-1 mutant develops normally in the presence of relatively non-pathogenic bacteria, infection of the xbp-1 mutant with P. aeruginosa leads to disruption of ER morphology and larval lethality. Unexpectedly, the larval lethality phenotype on pathogenic P. aeruginosa is suppressed by loss of PMK-1-mediated immunity. Furthermore, hyperactivation of PMK-1 causes larval lethality in the xbp-1 mutant even in the absence of pathogenic bacteria. Our data establish innate immunity as a physiologically relevant inducer of ER stress during C. elegans development and indicate that an ancient, conserved role for XBP-1 may be to protect the host organism from the detrimental effects of mounting an innate immune response to microbes.

Physiological IRE-1-XBP-1 and PEK-1 signaling in Caenorhabditis elegans larval development and immunity.

Endoplasmic reticulum (ER) stress activates the Unfolded Protein Response, a compensatory signaling response that is mediated by the IRE-1, PERK/PEK-1, and ATF-6 pathways in metazoans. Genetic studies have implicated roles for UPR signaling in animal development and disease, but the function of the UPR under physiological conditions, in the absence of chemical agents administered to induce ER stress, is not well understood. Here, we show that in Caenorhabditis elegans XBP-1 deficiency results in constitutive ER stress, reflected by increased basal levels of IRE-1 and PEK-1 activity under physiological conditions. We define a dynamic, temperature-dependent requirement for XBP-1 and PEK-1 activities that increases with immune activation and at elevated physiological temperatures in C. elegans. Our data suggest that the negative feedback loops involving the activation of IRE-1-XBP-1 and PEK-1 pathways serve essential roles, not only at the extremes of ER stress, but also in the maintenance of ER homeostasis under physiological conditions.

Phosphorylation of the conserved transcription factor ATF-7 by PMK-1 p38 MAPK regulates innate immunity in Caenorhabditis elegans.

Innate immunity in Caenorhabditis elegans requires a conserved PMK-1 p38 mitogen-activated protein kinase (MAPK) pathway that regulates the basal and pathogen-induced expression of immune effectors. The mechanisms by which PMK-1 p38 MAPK regulates the transcriptional activation of the C. elegans immune response have not been identified. Furthermore, in mammalian systems the genetic analysis of physiological targets of p38 MAPK in immunity has been limited. Here, we show that C. elegans ATF-7, a member of the conserved cyclic AMP-responsive element binding (CREB)/activating transcription factor (ATF) family of basic-region leucine zipper (bZIP) transcription factors and an ortholog of mammalian ATF2/ATF7, has a pivotal role in the regulation of PMK-1-mediated innate immunity. Genetic analysis of loss-of-function alleles and a gain-of-function allele of atf-7, combined with expression analysis of PMK-1-regulated genes and biochemical characterization of the interaction between ATF-7 and PMK-1, suggest that ATF-7 functions as a repressor of PMK-1-regulated genes that undergoes a switch to an activator upon phosphorylation by PMK-1. Whereas loss-of-function mutations in atf-7 can restore basal expression of PMK-1-regulated genes observed in the pmk-1 null mutant, the induction of PMK-1-regulated genes by pathogenic Pseudomonas aeruginosa PA14 is abrogated. The switching modes of ATF-7 activity, from repressor to activator in response to activated PMK-1 p38 MAPK, are reminiscent of the mechanism of regulation mediated by the corresponding ancestral Sko1p and Hog1p proteins in the yeast response to osmotic stress. Our data point to the regulation of the ATF2/ATF7/CREB5 family of transcriptional regulators by p38 MAPK as an ancient conserved mechanism for the control of innate immunity in metazoans, and suggest that ATF2/ATF7 may function in a similar manner in the regulation of mammalian innate immunity.

"Low-value" glycemic outcomes among older adults with diabetes cared for by primary care nurse practitioners or physicians: A retrospective cohort study.

BACKGROUND: "Low-value" healthcare is care without benefit to patients. Overly intensive glycemic control (i.e., HgbA1C < 7 %) can cause harm to patients at high risk of hypoglycemia, particularly among older adults with co-morbidities. It is unknown whether overly intensive glycemic control differs among patients with diabetes and at high-risk of hypoglycemia cared for by primary care nurse practitioners versus physicians. OBJECTIVE: This study examined patients with diabetes at high risk of hypoglycemia receiving primary care between Jan 2010 and Jan 2012, comparing patients reassigned to nurse practitioners to those reassigned to physicians after their previous physician separated from practice in an integrated United States health system. DESIGN: This was a retrospective cohort study. Study outcomes were collected at two years after reassignment to a new primary care provider. Outcomes were predicted probabilities of HgbA1C < 7 % using two-stage residual inclusion instrumental variable models, controlling for baseline confounders. SETTING: Primary care clinics within the United States Veterans Health Administration. PARTICIPANTS: 38,543 patients with diabetes at increased risk for hypoglycemia (age ≥ 65 years with renal disease, dementia, or cognitive impairment), who had their primary care physician leave the Veterans Health Administration and who were reassigned to a new primary care provider in the following year. RESULTS: Cohort patients were on average 76 years and 99 % men. Of these, 33,700 were reassigned to physicians and 4843 to nurse practitioners. After two years with their new provider, in adjusted models, patients reassigned to nurse practitioners had a -20.4 percentage-point [95 % CI -37.9 to -2.8] lower probability of two-year HgbA1C < 7 %. CONCLUSIONS: Aligned with prior studies on care quality, rates of overly intensive glycemic control may be appropriately lower among older patients with diabetes at high-risk of hypoglycemia, cared for by nurse practitioners than physicians. TWEETABLE ABSTRACT: Primary care nurse practitioners deliver equivalent or better rates of low-value diabetes care for older patients, compared to physicians.

Molecular detection of SARS-CoV-2 and differentiation of Omicron and Delta variant strains.

The SARS-CoV-2 virus is the causative agent of COVID-19 and has undergone continuous mutations throughout the pandemic. The more transmissible Omicron variant has quickly spread and is replacing the Delta variant as the most prevalent strain globally, including in the United States. A new molecular assay that can detect and differentiate both the Delta and Omicron variants was developed. A collection of 660,035 SARS-CoV-2 full- or near-full genomes, including 169,454 Delta variant and 24,202 Omicron variant strains, were used for primer and probe designs. In silico data analysis predicted an assay coverage of >99% of all strains, including >99% of the Delta and >99% of Omicron strains. The Omicron variant differential test was designed based on the Δ31-33 aa deletion in the N-gene, which is present in the original B.1.1.529 main genotype, BA.1, as well as in BA.2 and BA.3 subtypes. Therefore, the assay should detect the majority of all Omicron variant strains. Standard curves generated with human clinical samples indicated that the PCR amplification efficiencies were 104%, 90.7% and 90.4% for the Omicron, Delta, and non-Delta/non-Omicron wild-type genotypes, respectively. Correlation coefficients of the standard curves were all >0.99. The detection limit of the assay was 14.3, 32.0, and 21.5 copies per PCR reaction for Omicron, Delta, and wild-type genotypes, respectively. The assay was designed to specifically detect SAR-CoV-2 strains. Selected samples with Omicron, Delta and wild-type genotypes identified by the RT-qPCR assay were also confirmed by sequencing. The assay did not detect any animal coronavirus-positive samples that were tested. Human nasal swab samples that previously tested positive (n = 182) or negative (n = 42) for SARS-CoV-2 by the ThermoFisher TaqPath COVID-19 Combo Kit, produced the same result with the new assay. Among positive samples, 55.5% (101/182), 23.1% (42/182), and 21.4% (39/182) were identified as Omicron, Delta, and non-Omicron/non-Delta wild-type genotypes, respectively.

Longitudinal variation in SARS-CoV-2 antibody levels and emergence of viral variants: a serological analysis.

BACKGROUND: Serological assays are being used to monitor antibody responses in individuals who had SARS-CoV-2 infection and those who received a COVID-19 vaccine. We aimed to determine whether such assays can predict neutralising antibody titres as antibody levels wane and viral variants emerge. METHODS: We measured antibody levels in serum samples from a cohort of 112 participants with SARS-CoV-2 infection using ten high-throughput serological tests and functional neutralisation assays. Serum samples were taken at baseline and at up to four subsequent visits. We assessed the effects of time and spike protein sequence variation on the performance and predictive value of the various assays. We did correlation analyses for individual timepoints using non-parametric Spearman correlation, and differences between timepoints were determined by use of a two-tailed Wilcoxon matched-pairs signed rank test. FINDINGS: Neutralising antibody titres decreased over the first few months post-infection but stabilised thereafter, at about 30% of the level observed shortly after infection. Serological assays commonly used to measure antibodies against SARS-CoV-2 displayed a range of sensitivities that declined to varying extents over time. Quantitative measurements generated by serological assays based on the spike protein were better at predicting neutralising antibody titres than those based on nucleocapsid, but performance was variable, and manufacturer positivity thresholds were not able to predict the presence or absence of detectable neutralising activity. Although we observed some deterioration in correlation between serological measurements and functional neutralisation activity, some assays maintained an ability to predict neutralising titres, even against variants of concern. INTERPRETATION: The ability of high-throughput serological assays to predict neutralising antibody titres is likely to be crucial for evaluation of immunity at the population scale. These data can facilitate the selection of the most suitable assays as surrogates of functional neutralising activity and suggest that such measurements might be useful in clinical practice. FUNDING: US National Institutes of Health and National Health Service Research Scotland BioResource.

Optimisation of whole blood and plasma manganese assay by ICP-MS without use of a collision cell.

BACKGROUND: Manganese (Mn) toxicity has been reported in patients receiving total parenteral nutrition. To avoid unnecessary exposure it is recommended by NICE (National Institute for Clinical Excellence) that blood Mn concentrations are monitored. The aim of the study was to develop a method using inductively coupled plasma mass spectrometry (ICP-MS) for the reliable determination of Mn in plasma and whole blood, as indices of acute and chronic exposure. METHODS: Whole blood and plasma samples were prepared by appropriate dilution (diluent containing 0.005% Triton X-100, 0.2% propan-2-ol, 0.2% butan-1-ol and 1% nitric acid) addition of an internal standard gallium, followed by centrifugation to remove cell debris. Thermo Fisher Scientific ExCell and X Series ICP-MS instruments were used to define and correct for polyatomic interference on Mn assay. RESULTS: Mn was quantified at mass 55 using aqueous calibration and the polyatomic interference from FeH was successfully eliminated by modified (Xt) skimmer cones but not with the collision cell (collision gas 7% H2 in He, flow rate 4-7 mL/min). The assay was validated showing good precision, limit of detection and percentage recovery. Good agreement was observed with the All Laboratory Trimmed Mean of External Quality Assurance samples y (in house)=1.1 (ALTM)-45.0 between values of 250 and 750 nmol/L. CONCLUSIONS: A method has been developed using ICP-MS for the analysis of whole blood and plasma Mn incorporating a novel method of eliminating interference by utilizing the different geometries of the Xt interface cones. The procedure is simple and robust with good precision and recovery over a wide dynamic range.

Reported analgesic administration to rabbits undergoing experimental surgical procedures.

BACKGROUND: It has become widely accepted that whenever animals are used in scientific procedures, the 3Rs principle of replacement, reduction and refinement described by William Russell and Rex Burch should be adhered to. Animals should be replaced with non-sentient alternatives if possible, the number of animals used should be reduced and experimental procedures should be refined to minimise pain, suffering and distress. Administration of analgesic agents to animals undergoing surgical procedures is a refinement used to alleviate pain. In this study, a structured literature review was carried out to examine current trends in analgesic administration to rabbits undergoing experimental surgical procedures. RESULTS: 128 papers from 51 peer-reviewed journals were selected for inclusion in this review. Reporting administration of systemic analgesia to rabbits in peer-reviewed scientific papers increased significantly from 16% to 50% between 1995-1997 and 2005-2007 (P < 0.001). Papers that reported ethical approval were more likely than papers that did not specify approval to report systemic analgesic administration (P < 0.001). When systemic analgesics were administered, buprenorphine was the most frequently used agent and non-steroidal anti-inflammatory drugs were used less frequently than opioids in both time periods. CONCLUSIONS: Although this review provides evidence that systemic analgesic administration to rabbits undergoing surgical procedures is increasing, rabbits do not always receive analgesia when they undergo experimental surgery. Other practices in rabbit perioperative care that could be improved, highlighted by this survey include: 1) changing the timing of analgesic administration by giving systemic analgesics pre- or perioperatively rather than only postoperatively, 2) using multimodal analgesia when pain is likely to be moderate to severe and 3) increasing the use of non-steroidal anti-inflammatory drugs and use of other techniques such as epidural analgesia particularly for orthopaedic procedures.

Comparison of SARS-CoV-2 serological assays for use in epidemiological surveillance in Scotland.

Background: Sero-surveillance of SARS-CoV-2 is crucial to monitoring levels of population exposure and informing public health responses, but may be influenced by variability in performance between available assays. Methods: Five commercial immunoassays and a neutralising activity assay were used to detect antibodies to SARS-CoV-2 in routine primary care and paediatric samples collected during the first wave of the pandemic in NHS Lothian, Scotland as part of ongoing surveillance efforts. For each assay, sensitivity and specificity was calculated relative to consensus results (majority of immunoassays positive = overall positive) and neutralising activity. Quantitative correlation was performed between serological and neutralising titres. Results: Seroprevalence ranged from 3.4-7.3 % in primary care patients and 3-5.9 % in paediatric patients according to different immunoassays. Neutralising activity was detectable in 2.8 % and 1.3 % respectively. Relative assay performance changed depending on comparison to immunoassay consensus versus neutralising activity and qualititative versus quantitative agreement. Cross-reactivity with endemic seasonal coronaviruses was confirmed by neutralising assay in false positives for one immunoassay. Presence of false positives for another assay was found specifically in paediatric but not adult samples. Conclusions: Five serological assays show variable accuracy when applied to the general population, impacting seroprevalence estimates. Assay performance may also vary in detection of protective neutralising antibody levels. These aspects should be considered in assay selection and interpretation in epidemiological studies.