Human neutrophil elastase (HNE) is a uniquely destructive serine protease with the ability to unleash a wave of proteolytic activity by destroying the inhibitors of other proteases. Although this ...phenomenon forms an important part of the innate immune response to invading pathogens, it is responsible for the collateral host tissue damage observed in chronic conditions such as chronic obstructive pulmonary disease (COPD), and in more acute disorders such as the lung injuries associated with COVID-19 infection. Previously, a combinatorially selected activity-based probe revealed an unexpected substrate preference for oxidised methionine, which suggests a link to oxidative pathogen clearance by neutrophils. Here we use oxidised model substrates and inhibitors to confirm this observation and to show that neutrophil elastase is specifically selective for the di-oxygenated methionine sulfone rather than the mono-oxygenated methionine sulfoxide. We also posit a critical role for ordered solvent in the mechanism of HNE discrimination between the two oxidised forms methionine residue. Preference for the sulfone form of oxidised methionine is especially significant. While both host and pathogens have the ability to reduce methionine sulfoxide back to methionine, a biological pathway to reduce methionine sulfone is not known. Taken together, these data suggest that the oxidative activity of neutrophils may create rapidly cleaved elastase “super substrates” that directly damage tissue, while initiating a cycle of neutrophil oxidation that increases elastase tissue damage and further neutrophil recruitment.
Atmospheric ammonia inhibits broiler performance. Quantified effects are based on older genetic stock with a BW of 2,000 g at 7 wk. In contrast, modern genetic stock reaches 3,200 g at 7 wk of age. ...To assess the impact on present day broilers, 2 trials were conducted exposing male broilers to graded levels (0, 25, 50, and 75 ppm) of aerial ammonia from 0 to 4 wk of age. Sixty, 1-d-old chicks were placed in environmentally controlled chambers, weighed weekly as a group, and processed with yield determined at 7 wk of age. Final BW was significantly depressed by 6 and 9% for the 50 and 75 ppm concentrations of ammonia as compared with 0 ppm. Also, mortality was significantly greater at the 75 ppm ammonia concentration, 13.9% compared with 5.8% for the 0 ppm treatment. Percentage yield of deboned meat per bird decreased slightly with increasing exposure to ammonia but was not statistically significant. Although current genetic stock reaches growout weights that are approximately 60% greater than those 2 decades ago, the relative quantified effects of ammonia exposure were similar. Additionally, statistical analysis of the results provided a simple equation, presented herein, for predicting the decline in BW of male broilers after exposure to ammonia.
This study examined responses of male broilers during a 49-d production cycle to 4 placement densities in 2 trials. Trials were pooled because no treatment x trial interaction occurred. In each ...trial, 1,488 male chicks were randomly placed into 32 floor pens to simulate final densities of 30 (37 chicks/pen), 35 (43 chicks/pen), 40 (50 chicks/pen), and 45 (56 chicks/pen) kg of BW/m2 of floor space based on a projected final BW of 3.29 kg. Growth rate and nutrient utilization were similar (P greater than or equal to 0.05) among the treatments from 1 to 32 d of age. From 1 to 49 d, BW gain (P = 0.011) and feed consumption (P = 0.029) were adversely affected by increasing the placement density from 30 to 45 kg of BW/m2 of floor space. The reduction in cumulative BW gain due to placement density can be partially explained by less feed consumption as evidenced by 95.4% of the sums of squares of BW gain being attributable to feed consumption. Litter moisture content (P = 0.025) and foot pad lesion score (P = 0.001) increased linearly with increasing placement density. Upon processing, whole carcass and breast meat yields relative to BW were not affected (P greater than or equal to 0.05) as density increased from 30 to 45 kg/m2. The proportion of whole carcasses with scratches, but not tears, on the back and thighs increased (P = 0.021) as density increased. These results indicate that increasing the density beyond 30 kg/m2 elicited some negative effects on live performance of heavy broilers.
To determine the sensitivity of orbital magnetic resonance imaging (MRI) in acute demyelinating optic neuritis (ON) in routine clinical practice, and the added value of a dedicated neuroradiology ...interpretation.
Retrospective chart review.
Patients with clinically proven ON evaluated between 2004 and 2014 in the University of Michigan neuro-ophthalmology clinics. Inclusion criteria involved visual recovery and orbital MRI completed within 30days of symptom onset and before corticosteroid treatment.
Demographics, clinical examination, and MRI report data (high T2 signal, gadolinium contrast enhancement) were abstracted for each eligible eye. Every MRI was reinterpreted by a neuroradiologist masked to the affected side. Descriptive statistics summarized patient and eye characteristics. Interrater agreement between the neuroradiologist and the radiology report for the radiographic diagnosis of ON was assessed with Cohen's kappa statistic.
Of 92 patients who met all inclusion criteria, 70 (76.1%) were reported to have at least 1 MRI feature consistent with ON. After dedicated review by a neuroradiologist, 77 (83.7%) were determined to have a positive MRI for ON. Agreement between the neuroradiologist and MRI report was moderate (κ = 0.63). Gadolinium enhancement was the most common feature in MRI positive ON (72 78.3% of neuroradiology reviewed MRIs; 66 71.7% of clinical MRI reports).
The sensitivity of MRI in ON was lower than previously reported and confirms the importance of making a clinical diagnosis of ON without relying on neuroimaging for confirmation. MRI interpretation by a skilled neuroradiologist increased sensitivity, underscoring the complexity of orbital MRI interpretation.
Déterminer la sensibilité de l'imagerie par résonance magnétique (IRM) orbitaire en présence d'une névrite optique (NO) démyélinisante aiguë dans la pratique clinique habituelle, et vérifier l'intérêt d'une interprétation spécialisée en neuroradiologie.
Examen rétrospectif de dossiers médicaux.
Patients atteints de NO cliniquement établie, évalués entre 2004 et 2014 dans les cliniques de neuro-ophtalmologie de l'Université du Michigan. Parmi les critères d'inclusion, citons la récupération visuelle et l'IRM orbitaire réalisée dans les 30 jours suivant l'apparition des symptômes et avant l'administration d'un corticostéroïde.
On a recensé les données démographiques et noté les résultats de l'examen clinique et de l'IRM (signal T2 élevé, produit de contraste à base de gadolinium) pour chaque œil admissible. Tous les clichés IRM ont été interprétés à nouveau par un neuroradiologiste qui ignorait de quel côté se trouvait la lésion. Les statistiques descriptives résumaient les caractéristiques propres aux patients et à leurs yeux. La concordance interexaminateur entre le neuroradiologiste et le rapport du radiologiste quant au diagnostic radiologique de la NO a été évaluée au moyen du coefficient Kappa de Cohen.
Sur les 92 patients qui répondaient à tous les critères d'inclusion, 70 (76,1 %) présentaient au moins une caractéristique IRM conforme au diagnostic de NO. Après son examen spécifique, le neuroradiologiste a déterminé que l'IRM de 77 patients (83,7 %) permettait le diagnostic de NO. La concordance entre le neuroradiologiste et le rapport IRM était modérée (κ = 0,63). L'augmentation au gadolinium était la caractéristique la plus fréquente du diagnostic positif de NO à l'IRM (72 78,3 % des IRM examinées en neuroradiologie; 66 71,7 % des rapports cliniques d'IRM).
La sensibilité de l'IRM dans la NO était plus faible que ce qui avait déjà été signalé, ce qui étaye l'importance d’établir le diagnostic clinique de NO sans se fier à la neuroimagerie. L'interprétation des images IRM par un neuroradiologiste qualifié a augmenté la sensibilité diagnostique, ce qui souligne la complexité de l'interprétation des IRM orbitaires.
Dengue virus (DENV) populations are characteristically highly diverse. Regular lineage extinction and replacement is an important dynamic DENV feature, and most DENV lineage turnover events are ...associated with increased incidence of disease. The role of genetic diversity in DENV lineage extinctions is not understood. We investigated the nature and extent of genetic diversity in the envelope (E) gene of DENV serotype 1 representing different lineages histories. A region of the DENV genome spanning the E gene was amplified and sequenced by Roche/454 pyrosequencing. The pyrosequencing results identified distinct sub-populations (haplotypes) for each DENV-1 E gene. A phylogenetic tree was constructed with the consensus DENV-1 E gene nucleotide sequences, and the sequences of each constructed haplotype showed that the haplotypes segregated with the Sanger consensus sequence of the population from which they were drawn. Haplotypes determined through pyrosequencing identified a recombinant DENV genome that could not be identified through Sanger sequencing. Nucleotide level sequence diversities of DENV-1 populations determined from SNP analysis were very low, estimated from 0.009-0.01. There were also no stop codon, frameshift or non-frameshift mutations observed in the E genes of any lineage. No significant correlations between the accumulation of deleterious mutations or increasing genetic diversity and lineage extinction were observed (p>0.5). Although our hypothesis that accumulation of deleterious mutations over time led to the extinction and replacement of DENV lineages was ultimately not supported by the data, our data does highlight the significant technical issues that must be resolved in the way in which population diversity is measured for DENV and other viruses. The results provide an insight into the within-population genetic structure and diversity of DENV-1 populations.
In this paper, we report on the two-year-long Fermi-Large Area Telescope observation of the peculiar blazar 4C +21.35 (PKS 1222+216). This source was in a quiescent state from the start of the ...science operations of the Fermi Gamma-ray Space Telescope in 2008 August until 2009 September, and then became more active, with gradually increasing flux and some moderately bright flares. In 2010 April and June, 4C +21.35 underwent a very strong GeV outburst composed of several major flares characterized by rise and decay timescales of the order of a day. During the outburst, the GeV spectra of 4C +21.35 displayed a broken power-law form with spectral breaks observed near 1-3 GeV photon energies. We demonstrate that, at least during the major flares, the jet in 4C +21.35 carried a total kinetic luminosity comparable to the total accretion power available to feed the outflow. We also discuss the origin of the break observed in the flaring spectra of 4C +21.35. We show that, in principle, a model involving annihilation of the GeV photons on the He II Lyman recombination continuum and line emission of "broad-line region" clouds may account for such. However, we also discuss the additional constraint provided by the detection of 4C +21.35 at 0.07-0.4 TeV energies by the MAGIC telescope, which coincided with one of the GeV flares of the source. We argue that there are reasons to believe that the lsim TeV emission of 4C +21.35 (as well as the GeV emission of the source, if co-spatial) is not likely to be produced inside the broad-line region zone of highest ionization (~1017 cm from the nucleus), but instead originates further away from the active center, namely, around the characteristic scale of the hot dusty torus surrounding the 4C +21.35 nucleus (~1019 cm).
DegP, a member of the HtrA family of proteins, conducts critical bacterial protein quality control by both chaperone and proteolysis activities. The regulatory mechanisms controlling these two ...distinct activities, however, are unknown. DegP activation is known to involve a unique mechanism of allosteric binding, conformational changes and oligomer formation. We have uncovered a novel role for the residues at the PDZ1:protease interface in oligomer formation specifically for chaperone substrates of Chlamydia trachomatis HtrA (DegP homolog). We have demonstrated that CtHtrA proteolysis could be activated by allosteric binding and oligomer formation. The PDZ1 activator cleft was required for the activation and oligomer formation. However, unique to CtHtrA was the critical role for residues at the PDZ1:protease interface in oligomer formation when the activator was an in vitro chaperone substrate. Furthermore, a potential in vivo chaperone substrate, the major outer membrane protein (MOMP) from Chlamydia, was able to activate CtHtrA and induce oligomer formation. Therefore, we have revealed novel residues involved in the activation of CtHtrA which are likely to have important in vivo implications for outer membrane protein assembly.
Three trials were conducted to assess the effects of stocking density on physiological adaptive responses of broilers. Male broilers were reared in floor pens under conditions similar to those used ...commercially in the United States. Accepted indicators of adaptation to a stressor were measured on d 49 including plasma concentrations of corticosterone, glucose, cholesterol, and total nitrites as an indicator of nitric oxide, as well as heterophil:lymphocyte ratio. In trial 1, calculated stocking densities were 20, 25, 30, 35, 40, 45, 50, and 55 kg of BW/m2 and in trials 2 and 3, stocking densities were 30, 35, 40, and 45 kg of BW/m2. Stocking densities were calculated based on a final BW of 3.3 kg. Linear trend analyses were used to assess the role of stocking density on each of the physiological parameters. Results indicate that stocking density did not cause physiological adaptive changes indicative of stress.
A previous study identified kartogenin (KGN) as a potent modulator of bone marrow mesenchymal stem/stromal cell (BMSC) chondrogenesis. This initial report did not contrast KGN directly against ...transforming growth factor-beta 1 (TGF-β1), the most common growth factor used in chondrogenic induction medium. Herein, we directly compared the in vitro chondrogenic potency of TGF-β1 and KGN using a high resolution micropellet model system. Micropellets were cultured for 7-14 days in medium supplemented with TGF-β1, KGN, or both TGF-β1 + KGN. Following 14 days of induction, micropellets exposed to TGF-β1 alone or TGF-β1 + KGN in combination were larger and produced more glycosominoglycan (GAG) than KGN-only cultures. When TGF-β1 + KGN was used, GAG quantities were similar or slightly greater than the TGF-β1-only cultures, depending on the BMSC donor. BMSC micropellet cultures supplemented with KGN alone contracted in size over the culture period and produced minimal GAG. Indicators of hypertrophy were not mitigated in TGF-β1 + KGN cultures, suggesting that KGN does not obstruct BMSC hypertrophy. KGN appears to have weak chondrogenic potency in human BMSC cultures relative to TGF-β1, does not obstruct hypertrophy, and may not be a viable alternative to growth factors in cartilage tissue engineering.
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