6 research outputs found
Orrouy – Champlieu
Identifiant de l'opération archéologique : 9246 Date de l'opération : 2007 (SD) Deux zones du site ont été sondées. Le premier sondage dans la supposée basilique (A-2007) s’est révélé négatif. Le second, implanté dans le couloir du porticus post scaenam(B et C-2007), a permis de réexhumer un bloc calcaire identifié comme le montant de l'entrée monumentale du probable portique mis en évidence en 2005. Il a également révélé en relation avec la summa cavea, le plancher intérieur du portique fo..
Orrouy – Champlieu
Identifiant de l'opération archéologique : 8934 Date de l'opération : 2006 (SD) En 2006, l'exploration du théâtre et de la zone urbaine comprise entre le théâtre et la zone sacrée s'est poursuivie. La tentative pour vérifier l'existence d'un propylée symétrique correspondant à l'entrée occidentale du couloir de la summa cavean’a pas abouti. Le sondage E - 2006, n’a livré que des restes de maçonnerie bouleversés (US 155) correspondant à des blocs quadrangulaires peut-être utilisés comme bases ..
Orrouy – Champlieu
Identifiant de l'opération archéologique : 8934 Date de l'opération : 2006 (SD) En 2006, l'exploration du théâtre et de la zone urbaine comprise entre le théâtre et la zone sacrée s'est poursuivie. La tentative pour vérifier l'existence d'un propylée symétrique correspondant à l'entrée occidentale du couloir de la summa cavean’a pas abouti. Le sondage E - 2006, n’a livré que des restes de maçonnerie bouleversés (US 155) correspondant à des blocs quadrangulaires peut-être utilisés comme bases ..
Complement lectin pathway activation is associated with COVID-19 disease severity, independent of MBL2 genotype subgroups
IntroductionWhile complement is a contributor to disease severity in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, all three complement pathways might be activated by the virus. Lectin pathway activation occurs through different pattern recognition molecules, including mannan binding lectin (MBL), a protein shown to interact with SARS-CoV-2 proteins. However, the exact role of lectin pathway activation and its key pattern recognition molecule MBL in COVID-19 is still not fully understood.MethodsWe therefore investigated activation of the lectin pathway in two independent cohorts of SARS-CoV-2 infected patients, while also analysing MBL protein levels and potential effects of the six major single nucleotide polymorphisms (SNPs) found in the MBL2 gene on COVID-19 severity and outcome.ResultsWe show that the lectin pathway is activated in acute COVID-19, indicated by the correlation between complement activation product levels of the MASP-1/C1-INH complex (p=0.0011) and C4d (p<0.0001) and COVID-19 severity. Despite this, genetic variations in MBL2 are not associated with susceptibility to SARS-CoV-2 infection or disease outcomes such as mortality and the development of Long COVID.ConclusionIn conclusion, activation of the MBL-LP only plays a minor role in COVID-19 pathogenesis, since no clinically meaningful, consistent associations with disease outcomes were noted
Distinction of early complement classical and lectin pathway activation via quantification of C1s/C1-INH and MASP-1/C1-INH complexes using novel ELISAs
The most commonly used markers to assess complement activation are split products that are produced through activation of all three pathways and are located downstream of C3. In contrast, C4d derives from the cleavage of C4 and indicates either classical (CP) or lectin pathway (LP) activation. Although C4d is perfectly able to distinguish between CP/LP and alternative pathway (AP) activation, no well-established markers are available to differentiate between early CP and LP activation. Active enzymes of both pathways (C1s/C1r for the CP, MASP-1/MASP-2 for the LP) are regulated by C1 esterase inhibitor (C1-INH) through the formation of covalent complexes. Aim of this study was to develop validated immunoassays detecting C1s/C1-INH and MASP-1/C1-INH complex levels. Measurement of the complexes reveals information about the involvement of the respective pathways in complement-mediated diseases. Two sandwich ELISAs detecting C1s/C1-INH and MASP-1/C1-INH complex were developed and tested thoroughly, and it was investigated whether C1s/C1-INH and MASP-1/C1-INH complexes could serve as markers for either early CP or LP activation. In addition, a reference range for these complexes in healthy adults was defined, and the assays were clinically validated utilizing samples of 414 COVID-19 patients and 96 healthy controls. The immunoassays can reliably measure C1s/C1-INH and MASP-1/C1-INH complex concentrations in EDTA plasma from healthy and diseased individuals. Both complex levels are increased in serum when activated with zymosan, making them suitable markers for early classical and early lectin pathway activation. Furthermore, measurements of C1-INH complexes in 96 healthy adults showed normally distributed C1s/C1-INH complex levels with a physiological concentration of 1846 ± 1060 ng/mL (mean ± 2SD) and right-skewed distribution of MASP-1/C1-INH complex levels with a median concentration of 36.9 (13.18 - 87.89) ng/mL (2.5-97.5 percentile range), while levels of both complexes were increased in COVID-19 patients (p<0.0001). The newly developed assays measure C1-INH complex levels in an accurate way. C1s/C1-INH and MASP-1/C1-INH complexes are suitable markers to assess early classical and lectin pathway activation. An initial reference range was set and first studies showed that these markers have added value for investigating and unraveling complement activation in human disease
Brainstem neurochemical profiles after hospitalisation for COVID-19: a 7T MR spectroscopy study
BackgroundSomatic, cognitive and mental health issues have been identified in three-quarters of people 5 months after hospitalisation for severe acute SARS-CoV-2 (COVID-19) infection. The underlying neuroanatomical basis of these symptoms remains unclear, but recent studies suggest a role for altered brainstem physiology. We aimed to test the hypothesis that brainstem neurochemical profiles differ in patients who had been hospitalised for COVID-19 compared to matched controls using 7T magnetic resonance spectroscopy (MRS).MethodsThis prospective case–control study recruited 34 individuals who were hospitalised for COVID-19 and 15 healthy controls with no history of COVID-19 infection from two major UK hospitals before vaccines became available. The participants underwent 7T semi-adiabatic localization by adiabatic selective refocusing (sLASER) 1H-MRS at the ponto-medullary junction. Water-referenced metabolite concentrations were compared between the patients and controls and correlated with infection severity, as measured by maximum C-reactive protein (CRPmax) assay during inpatient admission. Linear mixed modelling was used with a 0.05 significance level.ResultsSpectral quality was high/acceptable in 44/49 participants according to the MRS Consensus criteria. The magnitude of inflammation during patient admission (i.e., CRPmax) correlated positively with myo-inositol concentration (β = 0.005, p = 0.035), as did patient-reported symptoms (β = −0.564, p = 0.023). However, metabolite concentrations were not significantly different between the patients and controls.ConclusionWe show the feasibility of assessing brainstem neurochemical profiles using 7T 1H-MRS in a multi-centre study. Technical limitations at one site’s 7T MRI led to variable repetition times, which limited our statistical power and should be avoided in future studies. Our findings highlight the need for further investigation into the role of neuroinflammation in post-acute COVID-19
