The prevalence of middle ear pathogens in the outer ear canal and the nasopharyngeal cavity of healthy young adults

AbstractCulturing middle ear fluid samples from children with chronic otitis media with effusion (OME) using standard techniques results in the isolation of bacterial species in approximately 30–50% of the cases. Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis, the classic middle ear pathogens of acute otitis media, are involved but, recently, several studies suggested Alloiococcus otitidis as an additional pathogen. In the present study, we used species-specific PCRs to establish the prevalence, in both the nasopharyngeal cavity and the outer ear, of H. influenzae, M. catarrhalis, S. pneumoniae and A. otitidis. The study group consisted of 70 healthy volunteers (aged 19–22 years). The results indicate a high prevalence (>80%) of A. otitidis in the outer ear in contrast to its absence in the nasopharynx. H. influenzae was found in both the outer ear and the nasopharynx (6% and 14%, respectively), whereas S. pneumoniae and M. catarrhalis were found only in the nasopharynx (9% and 34%, respectively). A. otitidis, described as a fastidious organism, were able to be cultured using an optimized culture protocol, with prolonged incubation, which allowed the isolation of A. otitidis in five of the nine PCR-positive samples out of the total of ten samples tested. Given the absence of the outer ear inhabitant A. otitidis from the nasopharynx, its role in the aetiology of OME remains ambiguous because middle ear infecting organisms are considered to invade the middle ear from the nasopharynx through the Eustachian tube

QTLs for Morphogenetic Traits in Medicago Truncatula

Plant morphogenesis that includes growth, development and flowering date, drives a large number of agronomical important traits in both grain and forage crops. Quantitative trait locus (QTL) mapping is a way to locate zones of the genome that are involved in the variations observed in a segregating population. Co-location of QTLs and candidate genes is an indication of the involvement of the genes in the variation. The objective of this study was to analyse segregation of aerial morphogenetic traits in a mapping population of recombinant inbred lines of the model legume species M. truncatula , to locate QTLs and candidate genes

Depth-Dependent Compressive Equilibrium Properties of Articular Cartilage Explained by Its Composition,” Biomech.

Abstract For this study, we hypothesized that the depthdependent compressive equilibrium properties of articular cartilage are the inherent consequence of its depth-dependent composition, and not the result of depth-dependent material properties. To test this hypothesis, our recently developed fibril-reinforced poroviscoelastic swelling model was expanded to include the influence of intra-and extra-fibrillar water content, and the influence of the solid fraction on the compressive properties of the tissue. With this model, the depth-dependent compressive equilibrium properties of articular cartilage were determined, and compared with experimental data from the literature. The typical depth-dependent behavior of articular cartilage was predicted by this model. The effective aggregate modulus was highly strain-dependent. It decreased with increasing strain for low strains, and increases with increasing strain for high strains. This effect was more pronounced with increasing distance from the articular surface. The main insight from this study is that the depth-dependent material behavior of articular cartilage can be obtained from its depth-dependent composition only. This eliminates the need for the assumption that the material properties of the different constituents themselves vary with depth. Such insights are important for understanding cartilage mechanical behavior, cartilage damage mechanisms and tissue engineering studies

Miocene (23–13 Ma) continental paleotemperature record from the northern Mediterranean region (Digne-Valensole Basin, SE France) within a global climatic framework

During the Middle Miocene, the Earth’s climate transitioned from a warm phase, the Miocene Climatic Optimum (MCO, 16.9–14.7 Ma), to a colder phase associated by formation of major ice sheets on Antarctica. This climatic shift, the Middle Miocene Climatic Transition (MMCT, 14.7–13.8 Ma), considerably impacted not only the structure and formation of major ecosystems (e.g. Jimenez-Moreno & Suc, 2005) it also affected global ocean circulation (Holbourn et al., 2014), terrestrial temperatures as well as precipitation patterns (e.g. Methner et al., 2020). While the MCO and the subsequent MMCT are well described in marine records, knowledge about the magnitude and rate of terrestrial paleoclimate changes is often limited by lack of temporal resolution and reliable quantitative proxy records (Steinthorsdottir et al., 2021). Here, we present a long-term (23–13 Ma) biostratigraphically-controlled terrestrial stable (δ18O, δ13C) and clumped (Δ47) isotope paleosol carbonate record from the northern Mediterranean region (Digne-Valensole basin, SE France). When comparing the northern Mediterranean δ18O, δ13C and Δ47 record with age-equivalent counterparts from central Europe (Northern Alpine Foreland Basin, Switzerland), our Δ47 results from the Digne-Valensole basin reveal two important features: 1) Relatively warm and constant carbonate formation temperatures (ca. 30°C) for the Early Miocene (23–18.6 Ma) followed by 2) intensified temperature fluctuations with high values (ca. 37°C) at the onset of the MCO, most probably amplified by changes in seasonality of pedogenic carbonate formation. The combined Northern Alpine foreland and northern Mediterranean records display a coherent climate pattern for the Middle Miocene circum-Alpine foreland. In both records, high-amplitude, rapid changes in Δ47 temperatures (ca. 18°C within 400 ka) characterize the onset of the MCO and MMCT. We furthermore identify warm peaks during the MCO and a distinct fall in apparent Δ47-based temperatures at ca. 14 Ma that is in very good temporal agreement with oceanic isotope records and coincides with the documented global cooling following the MCT. Collectively, these data contribute to understanding of the dynamics and variability in atmospheric circulation controlling Middle to Late Miocene temperature dynamics in the Northern Mediterranean region

Phosphorylation of Glutamine Synthetase on Threonine 301 Contributes to Its Inactivation During Epilepsy

The astrocyte-specific enzyme glutamine synthetase (GS), which catalyzes the amidation of glutamate to glutamine, plays an essential role in supporting neurotransmission and in limiting NH4+ toxicity. Accordingly, deficits in GS activity contribute to epilepsy and neurodegeneration. Despite its central role in brain physiology, the mechanisms that regulate GS activity are poorly defined. Here, we demonstrate that GS is directly phosphorylated on threonine residue 301 (T301) within the enzyme’s active site by cAMP-dependent protein kinase (PKA). Phosphorylation of T301 leads to a dramatic decrease in glutamine synthesis. Enhanced T301 phosphorylation was evident in a mouse model of epilepsy, which may contribute to the decreased GS activity seen during this trauma. Thus, our results highlight a novel molecular mechanism that determines GS activity under both normal and pathological conditions.</p

Dependence of Intramyocardial Pressure and Coronary Flow on Ventricular Loading and Contractility: A Model Study

The phasic coronary arterial inflow during the normal cardiac cycle has been explained with simple (waterfall, intramyocardial pump) models, emphasizing the role of ventricular pressure. To explain changes in isovolumic and low afterload beats, these models were extended with the effect of three-dimensional wall stress, nonlinear characteristics of the coronary bed, and extravascular fluid exchange. With the associated increase in the number of model parameters, a detailed parameter sensitivity analysis has become difficult. Therefore we investigated the primary relations between ventricular pressure and volume, wall stress, intramyocardial pressure and coronary blood flow, with a mathematical model with a limited number of parameters. The model replicates several experimental observations: the phasic character of coronary inflow is virtually independent of maximum ventricular pressure, the amplitude of the coronary flow signal varies about proportionally with cardiac contractility, and intramyocardial pressure in the ventricular wall may exceed ventricular pressure. A parameter sensitivity analysis shows that the normalized amplitude of coronary inflow is mainly determined by contractility, reflected in ventricular pressure and, at low ventricular volumes, radial wall stress. Normalized flow amplitude is less sensitive to myocardial coronary compliance and resistance, and to the relation between active fiber stress, time, and sarcomere shortening velocity