87 research outputs found
Observations of Heterospecific Courtship Behaviour in an Isolated Population of Rossâs Gulls (Rhodostethia rosea)
Heterospecific sexual behaviour is notable because it should be strongly deterred by natural and sexual selection. Here we report observations of both male and female Rossâs Gulls (Rhodostethia rosea) routinely engaging in sexual displays directed towards other species during the breeding season at a small, remote colony in the Canadian High Arctic. We suggest that in small, reproductively isolated populations, directing stereotyped courtship displays towards heterospecific partners may allow individuals to advertise fitness and experience to both male and female conspecifics and also accelerate hormonal development and readiness to mate during the brief and unpredictable High Arctic breeding season.Le comportement sexuel hĂ©tĂ©rospĂ©cifique est remarquable, car celui-ci devrait ĂȘtre fortement dissuadĂ© par la sĂ©lection naturelle et sexuelle. Ici, nous faisons mention dâobservations de mouettes rosĂ©es mĂąles et femelles (Rhodostethia rosea) exhibant rĂ©guliĂšrement des comportements sexuels envers dâautres espĂšces pendant la saison de reproduction dans une petite colonie Ă©loignĂ©e de lâExtrĂȘme-Arctique canadien. Nous suggĂ©rons quâau sein des petites populations reproductivement isolĂ©es, le fait dâaxer la pariade stĂ©rĂ©otypĂ©e sur des partenaires hĂ©tĂ©rospĂ©cifiques pourrait permettre aux individus de faire Ă©tat de leur forme physique et de leur expĂ©rience Ă leurs congĂ©nĂšres mĂąles et femelles, en plus dâaccĂ©lĂ©rer le dĂ©veloppement hormonal et lâĂ©tat de prĂ©paration Ă lâaccouplement pendant la brĂšve saison imprĂ©visible de reproduction dans lâExtrĂȘme-Arctique
Breeding Habitats and New Breeding Locations for Rossâs Gull (Rhodostethia rosea) in the Canadian High Arctic
Published accounts list only four breeding sites for Rossâs gull (Rhodostethia rosea) in North America, but the discovery of additional breeding sites in Queenâs Channel, Nunavut, adds to growing evidence that this species is established as a regular breeder in the Canadian High Arctic despite its current status as a Threatened Species in Canada. We present nine breeding records of Rossâs gull in Canada. Five are from Queenâs Channel alone, and these include two new breeding records from 2011. The geographic proximity and similarity in topography, microhabitat, and interspecific nesting associÂations that characterize Rossâs gull nesting sites in the Canadian High Arctic suggest that additional surveys of surrounding suitable habitat would confirm a stable and globally significant breeding population of this very poorly known species in North America.Selon des donnĂ©es dĂ©jĂ publiĂ©es, il nâexiste que quatre lieux de reproduction de la mouette rosĂ©e (Rhodostethia rosea) en AmĂ©rique du Nord. Cependant, la dĂ©couverte de nouveaux lieux de reproduction dans le chenal Queens, au Nunavut, vient renforcer les preuves selon lesquelles cette espĂšce est Ă©tablie en tant quâoiseau nicheur rĂ©gulier dans lâExtrĂȘme-Arctique canadien, mĂȘme si elle fait actuellement partie de la liste des espĂšces menacĂ©es au Canada. Nous prĂ©sentons neuf enregisÂtrements relatifs Ă la reproduction de la mouette rosĂ©e au Canada. Cinq de ces enregistrements sont relatifs au chenal Queens, dont deux nouveaux enregistrements de reproduction qui datent de 2011. La proximitĂ© gĂ©ographique et les similitudes sur le plan de la topographie, du microhabitat et des associations de nidification interspĂ©cifiques caractĂ©risant les lieux de reproduction de la mouette rosĂ©e dans lâExtrĂȘme-Arctique canadien laissent entendre que des levĂ©s supplĂ©mentaires dâhabitats environnants convenables permettraient de confirmer une population dâoiseaux nicheurs stable et gĂ©nĂ©ralement importante de cette espĂšce trĂšs peu connue en AmĂ©rique du Nord
Antagonism of the prokineticin system prevents and reverses allodynia and inflammation in a mouse model of diabetes
Neuropathic pain is a severe diabetes complication and its treatment is not satisfactory. It is associated with neuroinflammation-related events that participate in pain generation and chronicization. Prokineticins are a new family of chemokines that has emerged as critical players in immune system, inflammation and pain. We investigated the role of prokineticins and their receptors as modulators of neuropathic pain and inflammatory responses in experimental diabetes. In streptozotocin-induced-diabetes in mice, the time course expression of prokineticin and its receptors was evaluated in spinal cord and sciatic nerves, and correlated with mechanical allodynia. Spinal cord and sciatic nerve pro- and anti-inflammatory cytokines were measured as protein and mRNA, and spinal cord GluR subunits expression studied. The effect of preventive and therapeutic treatment with the prokineticin receptor antagonist PC1 on behavioural and biochemical parameters was evaluated. Peripheral immune activation was assessed measuring macrophage and T-helper cytokine production. An up-regulation of the Prokineticin system was present in spinal cord and nerves of diabetic mice, and correlated with allodynia. Therapeutic PC1 reversed allodynia while preventive treatment blocked its development. PC1 normalized prokineticin levels and prevented the up-regulation of GluN2B subunits in the spinal cord. The antagonist restored the pro-/anti-inflammatory cytokine balance altered in spinal cord and nerves and also reduced peripheral immune system activation in diabetic mice, decreasing macrophage proinflammatory cytokines and the T-helper 1 phenotype. The prokineticin system contributes to altered sensitivity in diabetic neuropathy and its inhibition blocked both allodynia and inflammatory events underlying disease
Prokineticin 2 upregulation in the peripheral nervous system has a major role in triggering and maintaining neuropathic pain in the chronic constriction injury model
The new chemokine Prokineticin 2 (PROK2) and its receptors (PKR1 and PKR2) have a role in inflammatory pain and
immunomodulation. Here we identified PROK2 as a critical mediator of neuropathic pain in the chronic constriction injury (CCI)
of the sciatic nerve in mice and demonstrated that blocking the prokineticin receptors with two PKR1-preferring antagonists (PC1
and PC7) reduces pain and nerve damage. PROK2 mRNA expression was upregulated in the injured nerve since day 3 post injury
(dpi) and in the ipsilateral DRG since 6 dpi. PROK2 protein overexpression was evident in Schwann Cells, infiltrating macrophages
and axons in the peripheral nerve and in the neuronal bodies and some satellite cells in the DRG. Therapeutic treatment of
neuropathic mice with the PKR-antagonist, PC1, impaired the PROK2 upregulation and signalling. This fact, besides alleviating
pain, brought down the burden of proinflammatory cytokines in the damaged nerve and prompted an anti-inflammatory repair
program. Such a treatment also reduced intraneural oedema and axon degeneration as demonstrated by the physiological skin
innervation and thickness conserved in CCI-PC1 mice. These findings suggest that PROK2 plays a crucial role in neuropathic pain
and might represent a novel target of treatment for this disease
Increasing incidence of HIVâ associated tuberculosis in Romanian injecting drug users
Background: A high prevalence of tuberculosis (TB) among HIVâpositive injecting drug users (IDUs) may fuel the TB epidemic in the general population of Romania. We determined the frequency and characteristics of TB in HIVâinfected IDUs referred to a national centre. / Methods: Prospective observational cohort study of all newlyâdiagnosed HIVâpositive IDUs admitted to Victor Babes Hospital, Bucharest, between January 2009 and December 2014. Socioâdemographics, clinical characteristics and outcomes of HIV/TB coâinfected IDUs were compared to HIVâpositive IDUs without TB. / Results: 170/598 (28.5%) HIVâinfected IDUs were diagnosed with TB. The prevalence increased from 12.5% in 2009 to 32.1% in 2014 (P < 0.001). HIV/TB coâinfected individuals had lower median CD4 cell counts 75 (vs. 450/mm3, P < 0.0001) and higher median HIV viral loads 5.6 log10 (vs. 4.9 log10, P < 0.0001) when presenting to healthcare services. 103/170 (60.6%) HIV/TB coâinfected IDUs were diagnosed with pulmonary TB. Resistant Mycobacterium tuberculosis strains were common, with 18/105 (17.1%) of patients having MultiâDrug Resistant (MDR) disease. Higher mortality rate was associated with TB coâinfection (P < 0.0001), extraâpulmonary TB (P = 0.0026) and extensively drug resistant TB (P = 0.024). / Conclusions: Tuberculosis (TB) is an increasing problem in HIVâinfected IDUs in Romania. Presentation is often with advanced HIV, significant TB drug resistance and consequent outcomes are poor
The impact of viral mutations on recognition by SARS-CoV-2 specific TÂ cells.
We identify amino acid variants within dominant SARS-CoV-2 TÂ cell epitopes by interrogating global sequence data. Several variants within nucleocapsid and ORF3a epitopes have arisen independently in multiple lineages and result in loss of recognition by epitope-specific TÂ cells assessed by IFN-Îł and cytotoxic killing assays. Complete loss of TÂ cell responsiveness was seen due to Q213K in the Aâ01:01-restricted CD8+ ORF3a epitope FTSDYYQLY207-215; due to P13L, P13S, and P13T in the Bâ27:05-restricted CD8+ nucleocapsid epitope QRNAPRITF9-17; and due to T362I and P365S in the Aâ03:01/Aâ11:01-restricted CD8+ nucleocapsid epitope KTFPPTEPK361-369. CD8+ TÂ cell lines unable to recognize variant epitopes have diverse TÂ cell receptor repertoires. These data demonstrate the potential for TÂ cell evasion and highlight the need for ongoing surveillance for variants capable of escaping TÂ cell as well as humoral immunity.This work is supported by the UK Medical Research Council (MRC); Chinese Academy of Medical Sciences(CAMS) Innovation Fund for Medical Sciences (CIFMS), China; National Institute for Health Research (NIHR)Oxford Biomedical Research Centre, and UK Researchand Innovation (UKRI)/NIHR through the UK Coro-navirus Immunology Consortium (UK-CIC). Sequencing of SARS-CoV-2 samples and collation of data wasundertaken by the COG-UK CONSORTIUM. COG-UK is supported by funding from the Medical ResearchCouncil (MRC) part of UK Research & Innovation (UKRI),the National Institute of Health Research (NIHR),and Genome Research Limited, operating as the Wellcome Sanger Institute. T.I.d.S. is supported by a Well-come Trust Intermediate Clinical Fellowship (110058/Z/15/Z). L.T. is supported by the Wellcome Trust(grant number 205228/Z/16/Z) and by theUniversity of Liverpool Centre for Excellence in Infectious DiseaseResearch (CEIDR). S.D. is funded by an NIHR GlobalResearch Professorship (NIHR300791). L.T. and S.C.M.are also supported by the U.S. Food and Drug Administration Medical Countermeasures Initiative contract75F40120C00085 and the National Institute for Health Research Health Protection Research Unit (HPRU) inEmerging and Zoonotic Infections (NIHR200907) at University of Liverpool inpartnership with Public HealthEngland (PHE), in collaboration with Liverpool School of Tropical Medicine and the University of Oxford.L.T. is based at the University of Liverpool. M.D.P. is funded by the NIHR Sheffield Biomedical ResearchCentre (BRC â IS-BRC-1215-20017). ISARIC4C is supported by the MRC (grant no MC_PC_19059). J.C.K.is a Wellcome Investigator (WT204969/Z/16/Z) and supported by NIHR Oxford Biomedical Research Centreand CIFMS. The views expressed are those of the authors and not necessarily those of the NIHR or MRC
Recurrent SARS-CoV-2 mutations in immunodeficient patients
Long-term severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in immunodeficient patients are an important source of variation for the virus but are understudied. Many case studies have been published which describe one or a small number of long-term infected individuals but no study has combined these sequences into a cohesive dataset. This work aims to rectify this and study the genomics of this patient group through a combination of literature searches as well as identifying new case series directly from the COVID-19 Genomics UK (COG-UK) dataset. The spike gene receptor-binding domain and N-terminal domain (NTD) were identified as mutation hotspots. Numerous mutations associated with variants of concern were observed to emerge recurrently. Additionally a mutation in the envelope gene, T30I was determined to be the second most frequent recurrently occurring mutation arising in persistent infections. A high proportion of recurrent mutations in immunodeficient individuals are associated with ACE2 affinity, immune escape, or viral packaging optimisation.There is an apparent selective pressure for mutations that aid cellâcell transmission within the host or persistence which are often different from mutations that aid inter-host transmission, although the fact that multiple recurrent de novo mutations are considered defining for variants of concern strongly indicates that this potential source of novel variants should not be discounted. © The Author(s) 2022. Published by Oxford University Press
Genomic reconstruction of the SARS-CoV-2 epidemic in England.
The evolution of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus leads to new variants that warrant timely epidemiological characterization. Here we use the dense genomic surveillance data generated by the COVID-19 Genomics UK Consortium to reconstruct the dynamics of 71 different lineages in each of 315 English local authorities between September 2020 and June 2021. This analysis reveals a series of subepidemics that peaked in early autumn 2020, followed by a jump in transmissibility of the B.1.1.7/Alpha lineage. The Alpha variant grew when other lineages declined during the second national lockdown and regionally tiered restrictions between November and December 2020. A third more stringent national lockdown suppressed the Alpha variant and eliminated nearly all other lineages in early 2021. Yet a series of variants (most of which contained the spike E484K mutation) defied these trends and persisted at moderately increasing proportions. However, by accounting for sustained introductions, we found that the transmissibility of these variants is unlikely to have exceeded the transmissibility of the Alpha variant. Finally, B.1.617.2/Delta was repeatedly introduced in England and grew rapidly in early summer 2021, constituting approximately 98% of sampled SARS-CoV-2 genomes on 26 June 2021
Spatial growth rate of emerging SARS-CoV-2 lineages in England, September 2020-December 2021
This paper uses a robust method of spatial epidemiological analysis to assess the spatial growth rate of multiple lineages of SARS-CoV-2 in the local authority areas of England, September 2020âDecember 2021. Using the genomic surveillance records of the COVID-19 Genomics UK (COG-UK) Consortium, the analysis identifies a substantial (7.6-fold) difference in the average rate of spatial growth of 37 sample lineages, from the slowest (Delta AY.4.3) to the fastest (Omicron BA.1). Spatial growth of the Omicron (B.1.1.529 and BA) variant was found to be 2.81Ă faster than the Delta (B.1.617.2 and AY) variant and 3.76Ă faster than the Alpha (B.1.1.7 and Q) variant. In addition to AY.4.2 (a designated variant under investigation, VUI-21OCT-01), three Delta sublineages (AY.43, AY.98 and AY.120) were found to display a statistically faster rate of spatial growth than the parent lineage and would seem to merit further investigation. We suggest that the monitoring of spatial growth rates is a potentially valuable adjunct to outbreak response procedures for emerging SARS-CoV-2 variants in a defined population
The SARS-CoV-2 Alpha variant was associated with increased clinical severity of COVID-19 in Scotland: A genomics-based retrospective cohort analysis
Objectives
The SARS-CoV-2 Alpha variant was associated with increased transmission relative to other variants present at the time of its emergence and several studies have shown an association between Alpha variant infection and increased hospitalisation and 28-day mortality. However, none have addressed the impact on maximum severity of illness in the general population classified by the level of respiratory support required, or death. We aimed to do this.
Methods
In this retrospective multi-centre clinical cohort sub-study of the COG-UK consortium, 1475 samples from Scottish hospitalised and community cases collected between 1st November 2020 and 30th January 2021 were sequenced. We matched sequence data to clinical outcomes as the Alpha variant became dominant in Scotland and modelled the association between Alpha variant infection and severe disease using a 4-point scale of maximum severity by 28 days: 1. no respiratory support, 2. supplemental oxygen, 3. ventilation and 4. death.
Results
Our cumulative generalised linear mixed model analyses found evidence (cumulative odds ratio: 1.40, 95% CI: 1.02, 1.93) of a positive association between increased clinical severity and lineage (Alpha variant versus pre-Alpha variants).
Conclusions
The Alpha variant was associated with more severe clinical disease in the Scottish population than co-circulating lineages
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