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Bacterial infections are associated with acute exacerbations of chronic obstructive pulmonary disease (AECOPD), but the mechanism is incompletely understood. In a COPD observational study (NCT01360398), sputum samples were collected monthly at the stable state and exacerbation. Post-hoc analyses of 1307 non-typeable Haemophilus influenzae (NTHi) isolates from 20 patients and 756 Moraxella catarrhalis isolates from 38 patients in one year of follow-up were conducted by multilocus sequence typing (MLST). All isolates came from cultured sputum samples that were analyzed for bacterial species presence, apparition (infection not detected at the preceding visit), or acquisition (first-time infection), with the first study visit as a baseline. Strain apparition or new strain acquisition was analyzed by MLST. The odds ratio (OR) of experiencing an exacerbation vs. stable state was estimated by conditional logistic regression modelling, stratified by patient. The culture results confirmed a significant association with exacerbation only for NTHi species presence (OR 2.28; 95% confidence interval [CI]: 1.12–4.64) and strain apparition (OR 2.38; 95% CI: 1.08–5.27). For M. catarrhalis, although confidence intervals overlapped, the association with exacerbation for first-time species acquisition (OR 5.99; 2.75–13.02) appeared stronger than species presence (OR 3.67; 2.10–6.40), new strain acquisition (OR 2.94; 1.43–6.04), species apparition (OR 4.18; 2.29–7.63), and strain apparition (OR 2.78; 1.42–5.42). This may suggest that previous M. catarrhalis colonization may modify the risk of exacerbation associated with M. catarrhalis infection. The results confirm that NTHi and M. catarrhalis infections are associated with AECOPD but suggest different dynamic mechanisms in triggering exacerbations. [ABSTRACT FROM AUTHOR]

Bacground/Aim. In order to determine the moment of creation of postural disorders, regardless of the causes of this problem, it is necessary to examine the moment of entry of children into a new environment, ie. in kindergarten or school. There is a weak evidence about the age period when foot deformity occurs, and the type of these deformities. The aim of this study was to establish the relationship between the occurrence of foot deformities and age characteristics of girls. Methods. The research was conducted in preschools „Radosno detinjstvo" in the region of Novi Sad, using the method of random selection, on the sample of 272 girls, 4-7 years of age, classified into four strata according to the year of birth. To determine the foot deformities measurement technique using computerized digitized pedografy (CDP) was applied. Results. In preschool population girls pes transversoplanus and calcanei valga deformities occurred in a very high percentage (over 90%). Disturbed longitudinal instep ie flat feet also appeared in a high percentage, but we noted the improvement of this deformity according to increasing age. Namely, there was a statistically significant correlation between the age and this deformity. As a child grows older, the deformity is lower. Conclusion. This study confirmed that the formation of foot arches probably does not end at the age of 3-4 years but lasts until school age. [ABSTRACT FROM AUTHOR]

Background/Aim. The main role of physical education is health and educational practices of cadets and all-round personality development. Instruction executing is successful only when the set requirements are realized. The aim of this study was to evaluate the effectiveness of physical education in order to rise physical capabilities of the Military Academy cadets during a 4-year education. Methods. The study was conducted in the Military Academy, Belgrade. A total of 120 cadets who at the beginning of the study were 19 years ± 6 months and at the end 23 years ± 6 months were included in this study. The study used the following tests for verification and assessment of physical fitness: pull-ups, lifting the trunk from the ground, standing long jump seats, running at 1,600 m and overcoming the infantry obstacles. The data were analyzed using statistical programs to calculate the central and dispersion parameters. The difference in the achieved results in the individual variables were evaluated by the univariate analysis of variance (ANOVA), while the differences in the system variables by region were identified by the multivariate analysis of variance (MANOVA) and discriminant analysis. The group membership was determined using profile analysis. Results. There were statistically significant differences in all the tests to evaluate the effectiveness of physical education during a 4-year study, except in the standing long jump test. The best average results in motor capabilities tests, were achieved after two years of study, while in the endurance tests showed the best results achieved at the end of a 4-years studying. Conclusion. The results of overcoming specific tests for the physical abilities of the Military Academy cadets show that the physical education curriculum only slightly improves the development of physical skills of cadets during a 4-year study. The existing program shows the best results in the pull-ups test of the ground troops, and the worst in the multiple motor control tests (endurance, strength and speed). [ABSTRACT FROM AUTHOR]

Abstract: Skin ageing is a complex biological process related to a decline in physiological and biochemical performance. A decline in the mitochondrial energy production is a feature of ageing at the cellular level. This is partially attributed to excessive production of reactive oxygen species such as superoxide and hydrogen peroxide in aged individuals. We have investigated the effect of (glyc)oxidative stress on two biochemical targets relevant for the energy metabolism of the skin. First, we showed an age dependent decline in the activity of the hydrogen peroxide detoxifying antioxidant catalase in stratum corneum on a chronically sun-exposed site. Furthermore catalase was sensitive to peroxynitrite-induced in vitro inactivation. Catalase mimetics as well as peroxynitrite scavengers are proposed to maintain hydrogen peroxide detoxification pathways. The second target was creatine kinase, an enzyme that controls the creatine–creatine phosphate shuttle. Creatine kinase lost activity after in vitro glycation by methylglyoxal. This activity loss could be prevented by antiglycation actives. These data suggest that biomolecules involved in energy homeostasis become damaged by different sources of stress. Actives specifically selected for optimal protection against these stress situations will decrease skin vulnerability and prevent the premature loss of skin function. [Copyright &y& Elsevier]

Type A γ-aminobutyric acid receptors (GABA A Rs) are pentameric ligand-gated chloride channels that mediate fast inhibitory signalling in neural circuits 1,2 and can be modulated by essential medicines including general anaesthetics and benzodiazepines 3 . Human GABA A R subunits are encoded by 19 paralogous genes that can, in theory, give rise to 495,235 receptor types. However, the principles that govern the formation of pentamers, the permutational landscape of receptors that may emerge from a subunit set and the effect that this has on GABAergic signalling remain largely unknown. Here we use cryogenic electron microscopy to determine the structures of extrasynaptic GABA A Rs assembled from α4, β3 and δ subunits, and their counterparts incorporating γ2 instead of δ subunits. In each case, we identified two receptor subtypes with distinct stoichiometries and arrangements, all four differing from those previously observed for synaptic, α1-containing receptors 4-7 . This, in turn, affects receptor responses to physiological and synthetic modulators by creating or eliminating ligand-binding sites at subunit interfaces. We provide structural and functional evidence that selected GABA A R arrangements can act as coincidence detectors, simultaneously responding to two neurotransmitters: GABA and histamine. Using assembly simulations and single-cell RNA sequencing data 8,9 , we calculated the upper bounds for receptor diversity in recombinant systems and in vivo. We propose that differential assembly is a pervasive mechanism for regulating the physiology and pharmacology of GABA A Rs., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Nanobodies are popular and versatile tools for structural biology. They have a compact single immunoglobulin domain organization, bind target proteins with high affinities while reducing their conformational heterogeneity and stabilize multi-protein complexes. Here we demonstrate that engineered nanobodies can also help overcome two major obstacles that limit the resolution of single-particle cryo-electron microscopy reconstructions: particle size and preferential orientation at the water-air interfaces. We have developed and characterized constructs, termed megabodies, by grafting nanobodies onto selected protein scaffolds to increase their molecular weight while retaining the full antigen-binding specificity and affinity. We show that the megabody design principles are applicable to different scaffold proteins and recognition domains of compatible geometries and are amenable for efficient selection from yeast display libraries. Moreover, we demonstrate that megabodies can be used to obtain three-dimensional reconstructions for membrane proteins that suffer from severe preferential orientation or are otherwise too small to allow accurate particle alignment.

The three-dimensional positions of atoms in protein molecules define their structure and their roles in biological processes. The more precisely atomic coordinates are determined, the more chemical information can be derived and the more mechanistic insights into protein function may be inferred. Electron cryo-microscopy (cryo-EM) single-particle analysis has yielded protein structures with increasing levels of detail in recent years 1,2 . However, it has proved difficult to obtain cryo-EM reconstructions with sufficient resolution to visualize individual atoms in proteins. Here we use a new electron source, energy filter and camera to obtain a 1.7 Å resolution cryo-EM reconstruction for a human membrane protein, the β3 GABA A receptor homopentamer 3 . Such maps allow a detailed understanding of small-molecule coordination, visualization of solvent molecules and alternative conformations for multiple amino acids, and unambiguous building of ordered acidic side chains and glycans. Applied to mouse apoferritin, our strategy led to a 1.22 Å resolution reconstruction that offers a genuine atomic-resolution view of a protein molecule using single-particle cryo-EM. Moreover, the scattering potential from many hydrogen atoms can be visualized in difference maps, allowing a direct analysis of hydrogen-bonding networks. Our technological advances, combined with further approaches to accelerate data acquisition and improve sample quality, provide a route towards routine application of cryo-EM in high-throughput screening of small molecule modulators and structure-based drug discovery.

Guidelines for cardiovascular drug therapy recommend monitoring serum digoxin concentration (SDC) in patients receiving digoxin treatment, especially those with renal dysfunction and hypokalemia. However, only a few studies have reported the prevalence of SDC monitoring and laboratory testing in clinical practice. Therefore, the aim of this study was to describe the frequency of SDC monitoring and laboratory testing in digoxin users and to assess the association between SDC monitoring and patient characteristics. We used the Japanese insurance claims data covering approximately 1.7 million patients aged 20-74 years between January 1, 2005 and March 31, 2014. All patients who had at least one prescription for digoxin were included. The frequency of SDC and laboratory tests was calculated and the association between patient characteristics and SDC monitoring was assessed using logistic regression analysis. A total of 98867 prescriptions of digoxin were issued to 3458 patients between 2005 and 2014. The annual mean frequencies of monitoring SDC, serum potassium level and serum creatinine level and of recording electrocardiograms was 16.8, 34.8, 38.7, and 24.1%, respectively. Atrial fibrillation, chronic heart failure, renal diseases, and use of oral anticoagulants were associated with SDC monitoring. We found the frequency of SDC monitoring to be relatively low in Japanese clinical practice.

Arrestins regulate the signaling of ligand-activated, phosphorylated G-protein-coupled receptors (GPCRs). Different patterns of receptor phosphorylation (phosphorylation barcode) can modulate arrestin conformations, resulting in distinct functional outcomes (for example, desensitization, internalization, and downstream signaling). However, the mechanism of arrestin activation and how distinct receptor phosphorylation patterns could induce different conformational changes on arrestin are not fully understood. We analyzed how each arrestin amino acid contributes to its different conformational states. We identified a conserved structural motif that restricts the mobility of the arrestin finger loop in the inactive state and appears to be regulated by receptor phosphorylation. Distal and proximal receptor phosphorylation sites appear to selectively engage with distinct arrestin structural motifs (that is, micro-locks) to induce different arrestin conformations. These observations suggest a model in which different phosphorylation patterns of the GPCR C terminus can combinatorially modulate the conformation of the finger loop and other phosphorylation-sensitive structural elements to drive distinct arrestin conformation and functional outcomes.