Development and operation of the defence COVID-19 lab as a SARS-CoV-2 diagnostic screening capability for UK military personnel.

BACKGROUND: In the face of the COVID-19 pandemic, the Defence Science and Technology Laboratory (Dstl) and Defence Pathology combined to form the Defence Clinical Lab (DCL), an accredited (ISO/IEC 17025:2017) high-throughput SARS-CoV-2 PCR screening capability for military personnel. LABORATORY STRUCTURE AND RESOURCE: The DCL was modular in organisation, with laboratory modules and supporting functions combining to provide the accredited SARS-CoV-2 (envelope (E)-gene) PCR assay. The DCL was resourced by Dstl scientists and military clinicians and biomedical scientists. LABORATORY RESULTS: Over 12 months of operation, the DCL was open on 289 days and tested over 72 000 samples. Six hundred military SARS-CoV-2-positive results were reported with a median E-gene quantitation cycle (Cq) value of 30.44. The lowest Cq value for a positive result observed was 11.20. Only 64 samples (0.09%) were voided due to assay inhibition after processing started. CONCLUSIONS: Through a sustained effort and despite various operational issues, the collaboration between Dstl scientific expertise and Defence Pathology clinical expertise provided the UK military with an accredited high-throughput SARS-CoV-2 PCR test capability at the height of the COVID-19 pandemic. The DCL helped facilitate military training and operational deployments contributing to the maintenance of UK military capability. In offering a bespoke capability, including features such as testing samples in unit batches and oversight by military consultant microbiologists, the DCL provided additional benefits to the UK Ministry of Defence that were potentially not available from other SARS-CoV-2 PCR laboratories. The links between Dstl and Defence Pathology have also been strengthened, benefitting future research activities and operational responses.

A Diaphragmic Traction Suture Increases Pleural Cavity Volume and Surgical Field Overview During Video-Assisted Thoracoscopic Surgery.

OBJECTIVES: An elevated hemidiaphragm may impair surgical field overview during video assisted thoracoscopic surgery (VATS) and may consequently jeopardize a safe surgical procedure or prolong the duration of surgery. The aim of this study was to evaluate if tension applied to a diaphragmatic suture improves the surgical field overview. METHODS: Following informed consent and at the surgeon's discretion during elective VATS procedures, a single stitch was placed at the posterior tendinous border of the diaphragm and retracted through the camera port. The surgical field overview was evaluated using a numeric rating scale (1-10) by the surgeon before and after applying tension during the procedure, and later by 9 VATS surgeons (> 10 years' experience) using video recordings. RESULTS: During a 4-month period, 43 patients scheduled for elective VATS by two surgeons gave informed consent to participate. The hemidiaphragm was elevated to such an extent in 27 patients that the surgeon placed a diaphragmatic stitch suture. When tension was applied to the suture, surgical field overview improved significantly (p < 0.001). CONCLUSION: A diaphragmatic traction suture improves surgical field overview in selected patients with elevation of the hemidiaphragm. This simple procedure may facilitate VATS in patients with impaired surgical field overview and consequently improve safety during VATS. CLINICAL TRIAL NUMBER: http://ClinicalTrials.gov (No. NCT04837950).

The influence of a lost society, the Sadlermiut, on the environment in the Canadian Arctic.

High latitude freshwater ecosystems are sentinels of human activity and environmental change. The lakes and ponds that characterize Arctic landscapes have a low resilience to buffer variability in climate, especially with increasing global anthropogenic stressors in recent decades. Here, we show that a small freshwater pond in proximity of the archaeological site "Native Point" on Southampton Island (Nunavut, Arctic Canada) is a highly sensitive environmental recorder. The sediment analyses allowed for pinpointing the first arrival of Sadlermiut culture at Native Point to ~ 1250 CE, followed by a dietary shift likely in response to the onset of cooling in the region ~ 1400 CE. The influence of the Sadlermiut on the environment persisted long after the last of their population perished in 1903. Presently, the pond remains a distorted ecosystem that has experienced fundamental shifts in the benthic invertebrate assemblages and accumulated anthropogenic metals in the sediment. Our multi-proxy paleolimnological investigation using geochemical and biological indicators emphasizes that direct and indirect anthropogenic impacts have long-term environmental implications on high latitude ecosystems.

CT in planning transcatheter aortic valve implantation procedures and risk assessment.

For surgical aortic valve replacement, the Society of Thoracic Surgeons score (STSS) is the reference standard for the prediction of operative risk. In transcatheter aortic valve implantation (TAVI) though, where the procedure itself is minimally invasive, the traditional risk assessment is supplemented by CTA. Through a consistent approach to the acquisition of high-quality images and the standardised reporting of annular measurements and adverse root and vascular features, patients at risk of complications can be identified. In turn, this may allow for a personalised procedural approach and treatment strategies devised to potentially reduce or mitigate this risk. This article provides a systematic and standardised approach to pre-procedural work-up with computed tomography angiography (CTA) and explores the current state of evidence and future areas of development in this rapidly developing field.

Author Correction: Insights into Pasteurellaceae carriage dynamics in the nasal passages of healthy beef calves.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Insights into Pasteurellaceae carriage dynamics in the nasal passages of healthy beef calves.

We investigated three bovine respiratory pathobionts in healthy cattle using qPCR optimised and validated to quantify Histophilus somni, Mannheimia haemolytica and Pasteurella multocida over a wide dynamic range. A longitudinal study was conducted to investigate the carriage and density of these bacteria in the nasal passages of healthy beef calves (N = 60) housed over winter in an experimental farm setting. The three pathobiont species exhibited remarkably different carriage rates and density profiles. At housing, high carriage rates were observed for P. multocida (95%), and H. somni (75%), while fewer calves were positive for M. haemolytica (13%). Carriage rates for all three bacterial species declined over the 75-day study, but not all individuals became colonised despite sharing of environment and airspace. Colonisation patterns ranged from continuous to intermittent and were different among pathobiont species. Interval-censored exponential survival models estimated the median duration of H. somni and P. multocida carriage at 14.8 (CI95%: 10.6-20.9) and 55.5 (CI95%: 43.3-71.3) days respectively, and found higher density P. multocida carriage was associated with slower clearance (p = 0.036). This work offers insights into the dynamics of pathobiont carriage and provides a potential platform for further data collection and modelling studies.

Efficacy of pamidronate in children with chronic non-bacterial osteitis using whole body MRI as a marker of disease activity.

BACKGROUND: To study the response to pamidronate using whole body magnetic resonance imaging (WB-MRI) in children with chronic non-bacterial osteitis (CNO) in a tertiary health centre. METHODS: The medical records of children under the age of sixteen with a diagnosis of chronic non-bacterial osteitis between 2005 and 2018 were reviewed. All those who were treated with pamidronate were included and relevant data was collected. Response to therapy was determined based on the status of lesions on WB- MRI. RESULTS: Forty six patients were included in the study. Pre- and post-treatment WB-MRI was available in forty patients. Cumulative lesions pre-treatment were 150 and reduced to 45 (30%) post-treatment. Seventeen patients (42.5%) had a good response with complete resolution of all lesions and nine patients (22.5%) worsened during or following treatment with pamidronate. Vertebral disease had a good response and 82.3% of the lesions resolved completely. CONCLUSION: Our study describes the experience with pamidronate in a tertiary health centre using WB-MRI as a marker of disease activity. Pamidronate was well tolerated in our cohort and treatment response was fairly good. SIGNIFICANCE AND INNOVATION: 1. Bisphosphonates can be used in the treatment of CNO when response to NSAIDs is suboptimal. 2. In the presence of spinal or mandibular lesions bisphosphonates were used as first line. 3. Treatment was escalated to a TNF blocker when response to bisphosphonates was suboptimal.

For debate: health service support planning for large-scale defensive land operations (part 2).

This is the second of two articles that considers the medical planning implications of large-scale defensive military operations. This paper describes a unified approach to theatre level health services support planning based on four phases: collection, hospitalisation, evacuation and reception. It highlights the need for a modular and agile system of medical capability building blocks that can be grouped together for specific military medical challenges. It also reintroduces the concepts of mass casualty and the medical reserve. These two papers are designed to encourage debate around how we should be organised to face the new challenges of health services support in potential peer-on-peer military operations.

For debate: health service support planning for large-scale defensive land operations (part 1).

This is the first of two articles that considers the medical planning implications of large-scale defensive military operations. This paper considers the military context and planning factors that may require a medical plan that is different from that seen in recent counterinsurgency operations. The scale and complexity of the challenge is likely to require a greater level of decentralisation and a more sophisticated approach to medical planning at the strategic and operational levels.

Blockade of vascular endothelial growth factor receptor 2 inhibits intraplaque haemorrhage by normalization of plaque neovessels.

BACKGROUND: Plaque angiogenesis is associated with atherosclerotic lesion growth, plaque instability and negative clinical outcome. Plaque angiogenesis is a natural occurring process to fulfil the increasing demand of oxygen and nourishment of the vessel wall. However, inadequate formed, immature plaque neovessels are leaky and cause intraplaque haemorrhage. OBJECTIVE: Blockade of VEGFR2 normalizes the unbridled process of plaque neovessel formation and induces maturation of nascent vessels resulting in prevention of intraplaque haemorrhage and influx of inflammatory cells into the plaque and subsequently increases plaque stability. METHODS AND RESULTS: In human carotid and vein graft atherosclerotic lesions, leaky plaque neovessels and intraplaque haemorrhage co-localize with VEGF/VEGFR2 and angiopoietins. Using hypercholesterolaemic ApoE3*Leiden mice that received a donor caval vein interposition in the carotid artery, we demonstrate that atherosclerotic vein graft lesions at t28 are associated with hypoxia, Hif1α and Sdf1 up-regulation. Local VEGF administration results in increased plaque angiogenesis. VEGFR2 blockade in this model results in a significant 44% decrease in intraplaque haemorrhage and 80% less extravasated erythrocytes compared to controls. VEGFR2 blockade in vivo results in a 32% of reduction in vein graft size and more stable lesions with significantly reduced macrophage content (30%), and increased collagen (54%) and smooth muscle cell content (123%). Significant decreased VEGF, angiopoietin-2 and increased Connexin 40 expression levels demonstrate increased plaque neovessel maturation in the vein grafts. VEGFR2 blockade in an aortic ring assay showed increased pericyte coverage of the capillary sprouts. CONCLUSION: Inhibition of intraplaque haemorrhage by controlling neovessels maturation holds promise to improve plaque stability.

Th17 responses to pneumococcus in blood and adenoidal cells in children.

Pneumococcal infections cause a large global health burden, and the search for serotype-independent vaccines continues. Existing conjugate vaccines reduce nasopharyngeal colonization by target serotypes. Such mucosal effects of novel antigens may similarly be important. CD4+ Th17 cell-dependent, antibody-independent reductions in colonization and enhanced clearance have been described in mice. Here we describe the evaluation of T helper type 17 (Th17) cytokine responses to candidate pneumococcal protein vaccine antigens in human cell culture, using adenoidal and peripheral blood mononuclear cells. Optimal detection of interleukin (IL)-17A was at day 7, and of IL-22 at day 11, in these primary cell cultures. Removal of CD45RO+ memory T cells abolished these responses. Age-associated increases in magnitude of responses were evident for IL-17A, but not IL-22, in adenoidal cells. There was a strong correlation between individual IL-17A and IL-22 responses after pneumococcal antigen stimulation (P < 0·015). Intracellular cytokine staining following phorbol myristate acetate (PMA)/ionomycin stimulation demonstrated that  > 30% CD4+ T cells positive for IL-22 express the innate markers γδT cell receptor and/or CD56, with much lower proportions for IL-17A+ cells (P < 0·001). Responses to several vaccine candidate antigens were observed but were consistently absent, particularly in blood, to PhtD (P < 0·0001), an antigen recently shown not to impact colonization in a clinical trial of a PhtD-containing conjugate vaccine in infants. The data presented and approach discussed have the potential to assist in the identification of novel vaccine antigens aimed at reducing pneumococcal carriage and transmission, thus improving the design of empirical clinical trials.

Differences in neuroimmune signalling between male and female patients suffering from knee osteoarthritis.

The primary aim was to identify cytokines involved in blood borne, neuroimmune joint-to-CNS signalling in knee osteoarthritis (OA) patients. Monocyte chemoattractant protein 1 (MCP1) and Interleukin-8 (IL-8) were elevated in the cerebrospinal fluid (CSF) in patients indicating neuroinflammation. Significant positive correlations were found for MCP1 across CSF, serum and synovial fluid (SF), in female, but not male patients. The results revealed sex differences in neuroimmune signalling and implicated MCP1 in blood borne joint-to-CNS signalling in female patients. Symptom severity correlated with IL-6 and IL-8 levels in SF, but was inversely associated with IL-6 and IL-8 levels in CSF, indicating that neuroinflammation in OA may be an adaptive, possibly neuroprotective mechanism promoting symptom reduction.

Implementing a nursing systems framework in a developing country.

AIM: To test the effect on patient mortality of implementing a nursing systems framework across a national health system. BACKGROUND: There have been five previous observational studies that have tested the effect of a nursing systems framework on clinical outcomes for patients. Implementation of a nursing systems framework in the health system of a developing country has not been evaluated. DESIGN: Quasi-experimental (before and after) study. METHOD: A nursing systems framework consisting of six themes: (i) Professionalisation; (ii) Education; (iii) Structure; (iv) Quality of nursing care; (v) An academic health system; and (vi) Communication (Professional), was implemented across the national health system of Qatar in March 2015. Routine administrative data were extracted (March 2014-February 2016) for elective admissions. Our primary and secondary outcomes were, respectively, all cause mortality at discharge and readmission to hospital (within 28 days of discharge). We split the data into two time periods: before (March 2014-February 2015) and after (March 2015-February 2016) the implementation of the nursing systems framework. Multivariable regression modelling was used to examine the effect of the framework on patient mortality, after adjusting for key confounding variables (patient age, episode acuity, intensive care admission and length of stay). FINDINGS: Data were extracted for 318 548 patients (year 1 = 130 829; year 2 = 187 725). After adjusting for confounding, there was a significant association between the implementation of the nursing systems framework, mortality and readmission. CONCLUSION AND IMPLICATIONS FOR NURSING POLICY AND PRACTICE: Our observations suggest that the implementation of a nursing systems framework may be important in improving outcomes for patients in emerging health systems.

Chronic recurrent multifocal osteomyelitis (CRMO) - advancing the diagnosis.

BACKGROUND: Chronic recurrent multifocal osteomyelitis (CRMO) is a little known inflammatory bone disease occurring primarily in children and adolescents. Delays in referral and diagnosis may lead to prolonged courses of antibiotics with in-patient care, unnecessary radiation exposure from multiple plain radiographs or bone scans and repeated surgery including bone biopsies. Children (aged < 18 years) diagnosed with CRMO between January 2005 and December 2012, reviewed at Bristol Royal Hospital for Children were included and all available data collected. Information regarding CRMO was sent to all orthopaedic surgeons in the region in 2009. The aim of the study was to examine the features of the cohort, to examine the length of time to diagnosis and to explore the criteria used for diagnosis with and without biopsy. FINDINGS: Over an 8 year period, 41 patients were diagnosed with CRMO. Symptom onset occurred at a median of 9 years of age and time to diagnosis had a median of 15 months (range 0-92). Correlation coefficient analysis for time to diagnosis by year showed statistical significance with a decreasing trend. From the cohort data, diagnostic criteria were developed; applied retrospectively, 34 (83 %) children may have been diagnosed using the criteria, without a biopsy. CONCLUSIONS: The data suggest that increasing knowledge of this condition may shorten time to diagnosis. Use of the Bristol diagnostic criteria by an experienced clinician may obviate the need for biopsy in some patients.

Acquired phototrophy through retention of functional chloroplasts increases growth efficiency of the sea slug Elysia viridis.

Photosynthesis is a fundamental process sustaining heterotrophic organisms at all trophic levels. Some mixotrophs can retain functional chloroplasts from food (kleptoplasty), and it is hypothesized that carbon acquired through kleptoplasty may enhance trophic energy transfer through increased host growth efficiency. Sacoglossan sea slugs are the only known metazoans capable of kleptoplasty, but the relative fitness contributions of heterotrophy through grazing, and phototrophy via kleptoplasts, are not well understood. Fitness benefits (i.e. increased survival or growth) of kleptoplasty in sacoglossans are commonly studied in ecologically unrealistic conditions under extended periods of complete darkness and/or starvation. We compared the growth efficiency of the sacoglossan Elysia viridis with access to algal diets providing kleptoplasts of differing functionality under ecologically relevant light conditions. Individuals fed Codium fragile, which provide highly functional kleptoplasts, nearly doubled their growth efficiency under high compared to low light. In contrast, individuals fed Cladophora rupestris, which provided kleptoplasts of limited functionality, showed no difference in growth efficiency between light treatments. Slugs feeding on Codium, but not on Cladophora, showed higher relative electron transport rates (rETR) in high compared to low light. Furthermore, there were no differences in the consumption rates of the slugs between different light treatments, and only small differences in nutritional traits of algal diets, indicating that the increased growth efficiency of E. viridis feeding on Codium was due to retention of functional kleptoplasts. Our results show that functional kleptoplasts from Codium can provide sacoglossan sea slugs with fitness advantages through photosynthesis.

Individual specialization to non-optimal hosts in a polyphagous marine invertebrate herbivore.

Factors determining the degree of dietary generalism versus specialism are central in ecology. Species that are generalists at the population level may in fact be composed of specialized individuals. The optimal diet theory assumes that individuals choose diets that maximize fitness, and individual specialization may occur if individuals' ability to locate, recognize, and handle different food types differ. We investigate if individuals of the marine herbivorous slug Elysia viridis, which co-occur at different densities on several green macroalgal species in the field, are specialized to different algal hosts. Individual slugs were collected from three original algal host species (Cladophora sericea, Cladophora rupestris and Codium fragile) in the field, and short-term habitat choice and consumption, as well as long-term growth (proxy for fitness), on four algal diet species (the original algal host species and Chaetomorpha melagonium) were studied in laboratory experiments. Nutritional (protein, nitrogen, and carbon content) and morphological (dry weight, and cell/utricle volume) algal traits were also measured to investigate if they correlated with the growth value of the different algal diets. E. viridis individuals tended to choose and consume algal species that were similar to their original algal host. Long-term growth of E. viridis, however, was mostly independent of original algal host, as all individuals reached a larger size on the non-host C. melagonium. E. viridis growth was positively correlated to algal cell/utricle volume but not to any of the other measured algal traits. Because E. viridis feeds by piercing individual algal cells, the results indicate that slugs may receive more cytoplasm, and thus more energy per unit time, on algal species with large cells/utricles. We conclude that E. viridis individuals are specialized on different hosts, but host choice in natural E. viridis populations is not determined by the energetic value of seaweed diets as predicted by the ODT.

Abundance and size distribution of the sacoglossan Elysia viridis on co-occurring algal hosts on the Swedish west coast.

Sacoglossans are specialized marine herbivores that tend to have a close evolutionary relationship with their macroalgal hosts, but the widely distributed species Elysia viridis can associate with several algal species. However, most previous investigations on the field abundance and size distribution of E. viridis have focussed on Codium spp. in the British Isles, and algae from this genus are considered superior hosts for E. viridis. In the present study, we investigated the abundance and size distribution of E. viridis on 6 potential host algae with differing morphologies (the septate species Cladophora sericea, Cladophora rupestris, Chaetomorpha melagonium, and Ceramium virgatum, as well as the siphonaceous species Codium fragile and Bryopsis sp.) at 2 sites on the Swedish west coast over the course of a year. In spring, slugs were almost absent from all algal hosts. In summer and autumn, E. viridis consistently occurred on several of the algal species at both sites. The highest number of small E. viridis were found on C. sericea, intermediate numbers of significantly larger E. viridis were found on C. rupestris, while fewer, intermediate sized animals were found on C. fragile. Throughout the study period, only a few E. viridis individuals were found on C. melagonium, Bryopsis sp., and C. virgatum. Our results indicate that E. viridis is an annual species in Sweden, capable of exploiting co-occurring congeneric and intergeneric algal hosts with differing morphologies. These results corroborate previous findings that E. viridis can exploit several different algal species, but does not indicate that C. fragile is a superior host.

Reference intervals for red cell variables and platelet counts in infants at 2, 5 and 13 months of age: a cohort study.

AIMS: To derive reference values for red cell variables and platelet counts from a cohort of infants sampled at precise ages during the first 13 months of life. METHODS: Blood counts, reticulocyte counts and zinc protoporphyrin concentrations were obtained from healthy term infants of North European ancestry at 2, 5 and 13 months of age. RESULTS: Mean cell volume (MCV) and mean cell haemoglobin (MCH) values did not differ significantly between 5 and 13 months and MCH concentration was unaffected by age. Values of all other variables at any one age differed significantly from those at the other two. Haemoglobin, mean cell haemoglobin, zinc protoporphyrin and platelet values (95% ranges) at 2 (n=119), 5 (n=97) and 13 months (n=42) were, respectively, 91-125, 101-129 and 105-133 g/L; 28.6-33.1, 24.5-28.7 and 24.3-28.7 pg; 36-116, 25-91 and 27-57 micromol/mol haem; and 216-658, 241-591 and 209-455×10(9)/L. At 2 and 5 months, respectively, 26.9% and 10.8% of subjects had platelet counts >500×10(9)/L. Reticulocyte counts at 2 months and MCV and MCH values at 5 months were significantly higher in girls. In boys, red cell distribution width values were significantly higher at 5 months, and zinc protoporphyrin values at both 2 and 5 months. CONCLUSIONS: These findings indicate the value of obtaining reference data at precise ages during infancy and confirm and extend earlier reports indicating a gender difference in laboratory measures used to assess iron status in early infancy.

Polysaccharide-protein conjugate vaccination induces antibody production but not sustained B-cell memory in the human nasopharyngeal mucosa.

Colonization of the nasopharyngeal mucosa by meningococcus and other polysaccharide (PS)-encapsulated bacteria precedes invasion. PS-conjugate vaccines induce PS-specific B-cell memory (B(MEM)) and also prevent colonization, thus blocking person-to-person transmission, generating herd protection. However, in isolation the B(MEM) are unable to sustain immunity. Furthermore, the duration of herd protection the vaccines induce appears limited. We demonstrate that, despite the persistence of PS-specific B(MEM), the population is not maintained within the nasopharynx. Although booster immunization results in the transient appearance of PS-specific B(MEM) within the mucosa, this reflects the re-circulation of systemic B(MEM) through the site rather than the generation of resident mucosal B(MEM). The induction of sustained PS-specific B(MEM) in the nasopharynx would allow the population to be activated by colonization, thus inhibiting subsequent invasion. It would also be expected to boost local mucosal immunity, thus extending herd protection. Strategies to generate PS-specific B(MEM) in the mucosa warrant further investigation.

Pneumococcal neuraminidase A: an essential upper airway colonization factor for Streptococcus pneumoniae.

Streptococcus pneumoniae colonizes the upper respiratory tract from where the organisms may disseminate systemically to cause life threatening infections. The mechanisms by which pneumococci colonize epithelia are not understood, but neuraminidase A (NanA) has a major role in promoting growth and survival in the upper respiratory tract. In this article we show that mutants of S. pneumoniae D39 deficient in NanA or neuraminidase B (NanB) are abrogated in adherence to three epithelial cell lines, and to primary nasopharyngeal cells. Adherence levels were partly restored by nanA complementation in trans. Enzymic activity of NanA was shown to be necessary for pneumococcal adherence to epithelial cells, and adherence of the nanA mutant was restored to wild-type level by pre-incubation of epithelial cells with Lactococcus lactis cells expressing NanA. Pneumococcal nanA or nanB mutants were deficient in biofilm formation, while expression of NanA on L. lactis or Streptococcus gordonii promoted biofilm formation by these heterologous host organisms. The results suggest that NanA is an enzymic factor mediating adherence to epithelial cells by decrypting receptors for adhesion, and functions at least in part as an adhesin in biofilm formation. Neuraminidase A thus appears to play multiple temporal roles in pneumococcal infection, from adherence to host tissues, colonization, and community development, to systemic spread and crossing of the blood-brain barrier.