The Loss of Functional Caspase-12 in Europe Is a Pre-Neolithic Event

Contains fulltext : 109878.pdf (publisher's version ) (Open Access)BACKGROUND: Caspase-12 (CASP12) modulates the susceptibility to sepsis. In humans, the "C" allele at CASP12 rs497116 has been associated with an increased risk of sepsis. Instead, the derived "T" allele encodes for an inactive caspase-12. Interestingly, Eurasians are practically fixed for the inactive variant, whereas in Sub-Saharan Africa the active variant is still common (~24%). This marked structure has been explained as a function of the selective advantage that the inactive caspase-12 confers by increasing resistance to infection. As regards to both when positive selection started acting and as to the speed with which fixation was achieved in Eurasia, estimates depend on the method and assumptions used, and can vary substantially. Using experimental evidence, we propose that, least in Eurasia, the increase in the frequency of the T allele might be related to the selective pressure exerted by the increase in zoonotic diseases transmission caused by the interplay between increased human population densities and a closer contact with animals during the Neolithic. METHODOLOG/PRINCIPAL FINDINGS: We genotyped CASP12 rs497116 in prehistoric individuals from 6 archaeological sites from the North of the Iberian Peninsula that date from Late Upper Paleolithic to Late Neolithic. DNA extraction was done from teeth lacking cavities or breakages using standard anti-contamination procedures, including processing of the samples in a positive pressure, ancient DNA-only chamber, quantitation of DNAs by qPCR, duplication, replication, genotyping of associated animals, or cloning of PCR products. Out of 50, 24 prehistoric individuals could finally be genotyped for rs497116. Only the inactive form of CASP12 was found. CONCLUSIONS/SIGNIFICANCE: We demonstrate that the loss of caspase-12 in Europe predates animal domestication and that consequently CASP12 loss is unlikely to be related to the impact of zoonotic infections transmitted by livestock

Distinct Roles for Dectin-1 and TLR4 in the Pathogenesis of Aspergillus fumigatus Keratitis

Aspergillus species are a major worldwide cause of corneal ulcers, resulting in visual impairment and blindness in immunocompetent individuals. To enhance our understanding of the pathogenesis of Aspergillus keratitis, we developed a murine model in which red fluorescent protein (RFP)-expressing A. fumigatus (Af293.1RFP) conidia are injected into the corneal stroma, and disease progression and fungal survival are tracked over time. Using Mafia mice in which c-fms expressing macrophages and dendritic cells can be induced to undergo apoptosis, we demonstrated that the presence of resident corneal macrophages is essential for production of IL-1β and CXCL1/KC, and for recruitment of neutrophils and mononuclear cells into the corneal stroma. We found that β-glucan was highly expressed on germinating conidia and hyphae in the cornea stroma, and that both Dectin-1 and phospho-Syk were up-regulated in infected corneas. Additionally, we show that infected Dectin-1−/− corneas have impaired IL-1β and CXCL1/KC production, resulting in diminished cellular infiltration and fungal clearance compared with control mice, especially during infection with clinical isolates expressing high β-glucan. In contrast to Dectin 1−/− mice, cellular infiltration into infected TLR2−/−, TLR4−/−, and MD-2−/− mice corneas was unimpaired, indicating no role for these receptors in cell recruitment; however, fungal killing was significantly reduced in TLR4−/− mice, but not TLR2−/− or MD-2−/− mice. We also found that TRIF−/− and TIRAP−/− mice exhibited no fungal-killing defects, but that MyD88−/− and IL-1R1−/− mice were unable to regulate fungal growth. In conclusion, these data are consistent with a model in which β-glucan on A.fumigatus germinating conidia activates Dectin-1 on corneal macrophages to produce IL-1β, and CXCL1, which together with IL-1R1/MyD88-dependent activation, results in recruitment of neutrophils to the corneal stroma and TLR4-dependent fungal killing

Distinct Roles for Dectin-1 and TLR4 in the Pathogenesis of Aspergillus fumigatus Keratitis

Aspergillus species are a major worldwide cause of corneal ulcers, resulting in visual impairment and blindness in immunocompetent individuals. To enhance our understanding of the pathogenesis of Aspergillus keratitis, we developed a murine model in which red fluorescent protein (RFP)-expressing A. fumigatus (Af293.1RFP) conidia are injected into the corneal stroma, and disease progression and fungal survival are tracked over time. Using Mafia mice in which c-fms expressing macrophages and dendritic cells can be induced to undergo apoptosis, we demonstrated that the presence of resident corneal macrophages is essential for production of IL-1β and CXCL1/KC, and for recruitment of neutrophils and mononuclear cells into the corneal stroma. We found that β-glucan was highly expressed on germinating conidia and hyphae in the cornea stroma, and that both Dectin-1 and phospho-Syk were up-regulated in infected corneas. Additionally, we show that infected Dectin-1−/− corneas have impaired IL-1β and CXCL1/KC production, resulting in diminished cellular infiltration and fungal clearance compared with control mice, especially during infection with clinical isolates expressing high β-glucan. In contrast to Dectin 1−/− mice, cellular infiltration into infected TLR2−/−, TLR4−/−, and MD-2−/− mice corneas was unimpaired, indicating no role for these receptors in cell recruitment; however, fungal killing was significantly reduced in TLR4−/− mice, but not TLR2−/− or MD-2−/− mice. We also found that TRIF−/− and TIRAP−/− mice exhibited no fungal-killing defects, but that MyD88−/− and IL-1R1−/− mice were unable to regulate fungal growth. In conclusion, these data are consistent with a model in which β-glucan on A.fumigatus germinating conidia activates Dectin-1 on corneal macrophages to produce IL-1β, and CXCL1, which together with IL-1R1/MyD88-dependent activation, results in recruitment of neutrophils to the corneal stroma and TLR4-dependent fungal killing

Safety of telephone triage in general practitioner cooperatives: do triage nurses correctly estimate urgency?

Contains fulltext : 53240.pdf (publisher's version ) (Closed access)BACKGROUND: In recent years, there has been a growth in the use of triage nurses to decrease general practitioner (GP) workloads and increase the efficiency of telephone triage. The actual safety of decisions made by triage nurses has not yet been assessed. OBJECTIVES: To investigate whether triage nurses accurately estimate the urgency level of health complaints when using the national telephone guidelines, and to examine the relationship between the performance of triage nurses and their education and training. Method: A cross-sectional, multicentre, observational study employing five mystery (simulated) patients who telephoned triage nurses in four GP cooperatives. The mystery patients played standardised roles. Each role had one of four urgency levels as determined by experts. The triage nurses called were asked to estimate the level of urgency after the contact. This level of urgency was compared with a gold standard. RESULTS: Triage nurses estimated the level of urgency of 69% of the 352 contacts correctly and underestimated the level of urgency of 19% of the contacts. The sensitivity and specificity of the urgency estimates provided by the triage nurses were found to be 0.76 and 0.95, respectively. The positive and negative predictive values of the urgency estimates were 0.83 and 0.93, respectively. A significant correlation was found between correct estimation of urgency and specific training on the use of the guidelines. The educational background (primary or secondary care) of the nurses had no significant relationship with the rate of underestimation. CONCLUSION: Telephone triage by triage nurses is efficient but possibly not safe, with potentially severe consequences for the patient. An educational programme for triage nurses is recommended. Also, a direct second safety check of all cases by a specially trained GP telephone doctor is advisable

Geographical localization of the ancient human remains analyzed in this work.

<p>Geographical localization of the ancient human remains analyzed in this work.</p

Temporal and geographical origin of the 24 prehistoric samples analyzed.

a<p>SJAPL: San Juan Ante Portam Latinam.</p>b<p>H2012: see Literature Ref. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037022#pone.0037022-Hervella1" target="_blank">[26]</a>. IR1999: See Literature Ref. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037022#pone.0037022-Izagirre1" target="_blank">[27]</a>.</p>c<p>based on the associated lithic industry.</p

Mapping the human genetic architecture of COVID-19

The genetic make-up of an individual contributes to the susceptibility and response to viral infection. Although environmental, clinical and social factors have a role in the chance of exposure to SARS-CoV-2 and the severity of COVID-191,2, host genetics may also be important. Identifying host-specific genetic factors may reveal biological mechanisms of therapeutic relevance and clarify causal relationships of modifiable environmental risk factors for SARS-CoV-2 infection and outcomes. We formed a global network of researchers to investigate the role of human genetics in SARS-CoV-2 infection and COVID-19 severity. Here we describe the results of three genome-wide association meta-analyses that consist of up to 49,562 patients with COVID-19 from 46 studies across 19 countries. We report 13 genome-wide significant loci that are associated with SARS-CoV-2 infection or severe manifestations of COVID-19. Several of these loci correspond to previously documented associations to lung or autoimmune and inflammatory diseases3–7. They also represent potentially actionable mechanisms in response to infection. Mendelian randomization analyses support a causal role for smoking and body-mass index for severe COVID-19 although not for type II diabetes. The identification of novel host genetic factors associated with COVID-19 was made possible by the community of human genetics researchers coming together to prioritize the sharing of data, results, resources and analytical frameworks. This working model of international collaboration underscores what is possible for future genetic discoveries in emerging pandemics, or indeed for any complex human disease