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The action of antibodies and of the haemolytic complement system does not induce immune immobilization of Treponema pallidum, but only destroys superficial wall structures of these Gram-negative organisms. In sensitized and complement coated treponemes the immobilization is a result of the lysozyme interaction with the mucopeptide layer of the cell wall. In a lysozyme-free medium, immunologically damaged treponemes are able to repair the defects in the outer layers of their cell wall structures. Furthermore, it is shown that the long lag period in immune immobilization of T. pallidum can only partly be explained by the interaction of lysozyme with the treponemes. [ABSTRACT FROM AUTHOR]

Comments on an article on the theory of the Liapunov exponents of Hamiltonian systems and the transition from regular to irregular classic motion. Method for calculating the fraction of the phase space; Significance of choosing the correct Poincaré section.

Nucleoid-associated proteins (NAPs) crucially contribute to organizing bacterial chromatin and regulating gene expression. Among the most highly expressed NAPs are the HU and integration host factor (IHF) proteins, whose functional homologues, HupB and mycobacterial integration host factor (mIHF), are found in mycobacteria. Despite their importance for the pathogenicity and/or survival of tubercle bacilli, the role of these proteins in mycobacterial chromosome organization remains unknown. Here, we used various approaches, including super-resolution microscopy, to perform a comprehensive analysis of the roles of HupB and mIHF in chromosome organization. We report that HupB is a structural agent that maintains chromosome integrity on a local scale, and that the lack of this protein alters chromosome morphology. In contrast, mIHF is a highly dynamic protein that binds DNA only transiently, exhibits susceptibility to the chromosomal DNA topology changes and whose depletion leads to the growth arrest of tubercle bacilli. Additionally, we have shown that depletion of Mycobacterium smegmatis integration host factor (msIHF) leads to chromosome shrinkage and replication inhibition., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Hołówka, Łebkowski, Feddersen, Giacomelli, Drużka, Makowski, Trojanowski, Broda, Bramkamp and Zakrzewska-Czerwińska.)

Background: People with chronic diseases have contact with several different professionals across hospital wards, municipality services and general practice and often experience lack of coherence. The purpose was to explore perceived barriers and facilitators to coherent rehabilitation pathways for health care users with inflammatory arthritis and how coherence can be improved., Methods: Semi-structured individual interviews were conducted before a planned inpatient rehabilitation stay, 2-3 weeks and 4-6 months after discharge. Thematic reflexive analysis guided the analysis of data. Concepts of person-centred care, complex adaptive systems and integrated care were applied in the interpretations., Results: In all, 11 participants with IA were included. There was one overarching theme, The importance of a person-centred approach, illuminating the significance of professionals who respect healthcare user' preferences. To use a person-centred approach, demands professionals who are interested in exploring the persons own values, preferences and experiences and incorporate these when planning care and rehabilitation.Connected to the overarching theme, three sub-themes were derived; 1) Experiences of empowerment and dis-empowerment, covering that most want to be in control and act themselves, but felt overwhelmed and lost energy and they tended to give up; 2) Experiences of communication and coordination, encompass how people feel forced to take on coordination and communication tasks themselves although they do not always feel qualified for this. Some asked for a coordination person and 3) Facing everyday life after discharge, covering how initiatives taken by professionals were not always experienced as helpful after discharge. Some gave up and some tried to find alternative paths themselves., Conclusion: Professionals taking a person-centred approach facilitated coherent rehabilitation pathways. This encompassed care with respect for individual needs and professionals who empowered patients to self-management. Furthermore, to be aware that interprofessional communication and coordination need to take place both between professional within the same department, between departments and between professionals in different sectors. After discharge, some patients were challenged in their everyday life when trying to follow the advice from the professionals. Professionals, who do not use a person-centred approach, hinder coherence. Patients thus feel compelled to take on communication and coordination tasks., (© 2022. The Author(s).)

In order to survive, bacterial cells rely on precise spatiotemporal organization and coordination of essential processes such as cell growth, chromosome segregation, and cell division. Given the general lack of organelles, most bacteria are forced to depend on alternative localization mechanisms, such as, for example, geometrical cues. DivIVA proteins are widely distributed in mainly Gram-positive bacteria and were shown to bind the membrane, typically in regions of strong negative curvature, such as the cell poles and division septa. Here, they have been shown to be involved in a multitude of processes: from apical cell growth and chromosome segregation in actinobacteria to sporulation and inhibition of division re-initiation in firmicutes. Structural analyses revealed that DivIVA proteins can form oligomeric assemblies that constitute a scaffold for recruitment of other proteins. However, it remained unclear whether interaction with partner proteins influences DivIVA dynamics. Using structured illumination microscopy (SIM), single-particle tracking (SPT) microscopy, and fluorescent recovery after photobleaching (FRAP) experiments, we show that DivIVA from Corynebacterium glutamicum is mobilized by its binding partner ParB. In contrast, we show that the interaction between Bacillus subtilis DivIVA and its partner protein MinJ reduces DivIVA mobility. Furthermore, we show that the loss of the rod-shape leads to an increase in DivIVA dynamics in both organisms. Taken together, our study reveals the modulation of the polar scaffold protein by protein interactors and cell morphology. We reason that this leads to a very simple, yet robust way for actinobacteria to maintain polar growth and their rod-shape. In B. subtilis , however, the DivIVA protein is tailored towards a more dynamic function that allows quick relocalization from poles to septa upon division.

ParB-like CTPases mediate the segregation of bacterial chromosomes and low-copy number plasmids. They act as DNA-sliding clamps that are loaded at parS motifs in the centromere of target DNA molecules and spread laterally to form large nucleoprotein complexes serving as docking points for the DNA segregation machinery. Here, we solve crystal structures of ParB in the pre- and post-hydrolysis state and illuminate the catalytic mechanism of nucleotide hydrolysis. Moreover, we identify conformational changes that underlie the CTP- and parS-dependent closure of ParB clamps. The study of CTPase-deficient ParB variants reveals that CTP hydrolysis serves to limit the sliding time of ParB clamps and thus drives the establishment of a well-defined ParB diffusion gradient across the centromere whose dynamics are critical for DNA segregation. These findings clarify the role of the ParB CTPase cycle in partition complex assembly and function and thus advance our understanding of this prototypic CTP-dependent molecular switch., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)

Division site selection is a vital process to ensure generation of viable offspring. In many rod-shaped bacteria, a dynamic protein system, termed the Min system, acts as a central regulator of division site placement. The Min system is best studied in Escherichia coli, where it shows a remarkable oscillation from pole to pole with a time-averaged density minimum at midcell. Several components of the Min system are conserved in the Gram-positive model organism Bacillus subtilis However, in B. subtilis, it is commonly believed that the system forms a stationary bipolar gradient from the cell poles to midcell. Here, we show that the Min system of B. subtilis localizes dynamically to active sites of division, often organized in clusters. We provide physical modeling using measured diffusion constants that describe the observed enrichment of the Min system at the septum. Mathematical modeling suggests that the observed localization pattern of Min proteins corresponds to a dynamic equilibrium state. Our data provide evidence for the importance of ongoing septation for the Min dynamics, consistent with a major role of the Min system in controlling active division sites but not cell pole areas. IMPORTANCE The molecular mechanisms that help to place the division septum in bacteria is of fundamental importance to ensure cell proliferation and maintenance of cell shape and size. The Min protein system, found in many rod-shaped bacteria, is thought to play a major role in division site selection. It was assumed that there are strong differences in the functioning and in the dynamics of the Min system in E. coli and B. subtilis Most previous attempts to address Min protein dynamics in B. subtilis have been hampered by the use of overexpression constructs. Here, functional fusions to Min proteins have been constructed by allelic exchange and state-of-the-art imaging techniques allowed to unravel an unexpected fast dynamic behavior of the B. subtilis Min system. Our data show that the molecular mechanisms leading to Min protein dynamics are not fundamentally different in E. coli and B. subtilis ., (Copyright © 2021 Feddersen et al.)

Nucleoid-associated proteins (NAPs) are responsible for maintaining highly organized and yet dynamic chromosome structure in bacteria. The genus Mycobacterium possesses a unique set of NAPs, including Lsr2, which is a DNA-bridging protein. Importantly, Lsr2 is essential for the M. tuberculosis during infection exhibiting pleiotropic activities including regulation of gene expression (mainly as a repressor). Here, we report that deletion of lsr2 gene profoundly impacts the cell morphology of M. smegmatis, which is a model organism for studying the cell biology of M. tuberculosis and other mycobacterial pathogens. Cells lacking Lsr2 are shorter, wider, and more rigid than the wild-type cells. Using time-lapse fluorescent microscopy, we showed that fluorescently tagged Lsr2 forms large and dynamic nucleoprotein complexes, and that the N-terminal oligomerization domain of Lsr2 is indispensable for the formation of nucleoprotein complexes in vivo. Moreover, lsr2 deletion exerts a significant effect on the replication time and replisome dynamics. Thus, we propose that the Lsr2 nucleoprotein complexes may contribute to maintaining the proper organization of the newly synthesized DNA and therefore influencing mycobacterial cell cycle.

Predictions of the atmospheric dispersion of radionuclides accidentally released from a nuclear power plant are influenced by two large sources of uncertainty: one associated with the meteorological data employed, and one with the source term, i.e. the temporal evolution of the amount and physical and chemical properties of the release. A methodology is presented for quantitative estimation of the variability of the prediction of atmospheric dispersion resulting from both sources of uncertainty. The methodology, which allows for efficient calculation, and thus is well suited for real-time assessment, is applied to a hypothetical accidental release of radionuclides., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Introduction: Rheumatoid arthritis (RA) is a chronic inflammatory disease, and patients with RA receive services in various settings-for example, in nurse-led follow-up consultations. The present study aimed to investigate how the management of RA in everyday life is expressed in interactions between nurses and women with RA during nursing consultations., Methods: The study was conducted in accordance with constructivist grounded theory, with data based on participant observations and subsequent interviews with 10 women with RA., Results: A core category was developed, "Collaboration through mutual acknowledgement", which documented how the women and nurses confirmed their shared understanding of the content and the structure of the consultation. Three subcategories were identified: (i) "On safe ground", which illustrated that biomedical factors, such as blood test results and pharmacological treatment, structured the basis of the dialogue; (ii) "Venturing forward", which documented how both parties were aware of each other's reactions when the dialogue dealt with women's perspectives of illness in their everyday lives; and (iii) "Gentle steering", which showed that the nurses gently steered the dialogue if the women strayed from the planned content., Conclusions: Both parties agreed that a disease perspective consistent with biomedical factors formed the basis for further dialogue. Subsequently, the women's perspectives on illness were included, and the women felt acknowledged. Therefore, the recommendation is that the consultations start by all parties agreeing on a shared agenda to facilitate the inclusion of the women's perspectives on illness., (© 2019 John Wiley & Sons, Ltd.)

Purpose: To explore how women with rheumatoid arthritis manage their illness, motherhood, and work life., Methods: A constructivist, grounded theory approach based on individual interviews and participant observations with 20 women with rheumatoid arthritis who participated in work life and had children living at home or were pregnant. After initial and focused coding Goffman's concepts of social identity were applied., Results: A core category: "Juggling meaningful identities" and three conceptual categories were developed: (1) Work life as the strongest identity marker; (2) Motherhood: a two-sided act; (3) Living with rheumatoid arthritis as an identity? Paid work, motherhood, and illness are linked to the women's social identities. The women construct and change their identities in interactions with children, partners, other parents, colleagues, and employers., Conclusion: The women attribute the highest priority to their professional identity, spending the majority of their time and energy in an effort to appear as "good stable workers". The disease is seen as a hindrance in this regard, and the illness identity is almost completely rejected. In motherhood, the women prioritize close interaction with their children, and deprioritize external activities. Extended outbreaks of the disease and issues regarding the children force the women to deprioritize working life. Implications for rehabilitation Juggling meaningful identities of rheumatoid arthritis, motherhood, and paid work challenge women in managing their everyday lives. Therefore, rehabilitation professionals should support individuals to develop new strategies to manage the challenges they experience regarding juggling motherhood and work ability. Work is a dominant identity marker for women with rheumatoid arthritis therefore, rehabilitation professionals have an important role to play in investigating possible ways for the individual to maintain employment or return to work. Living with rheumatoid arthritis and being a paid worker challenge women's role performance and thereby their identification as mothers. Therefore, rehabilitation professionals have to support the women and their families.

mNeonGreen fluorescent protein is capable of photo-switching, hence in principle applicable for super-resolution imaging. However, difficult-to-control blinking kinetics that lead to simultaneous emission of multiple nearby mNeonGreen molecules impedes its use for PALM. Here, we determined the on- and off- switching rate and the influence of illumination power on the simultaneous emission. Increasing illumination power reduces the probability of simultaneous emission, but not enough to generate high quality PALM images. Therefore, we introduce a simple data post-processing step that uses temporal and spatial information of molecule localizations to further reduce artifacts arising from simultaneous emission of nearby emitters. We also systematically evaluated various sample preparation steps to establish an optimized protocol to preserve cellular morphology and fluorescence signal. In summary, we propose a workflow for super-resolution imaging with mNeonGreen based on optimization of sample preparation, data acquisition and simple post-acquisition data processing. Application of our protocol enabled us to resolve the expected double band of bacterial cell division protein DivIVA, and to visualize that the chromosome organization protein ParB organized into sub-clusters instead of the typically observed diffraction-limited foci. We expect that our workflow allows a broad use of mNeonGreen for super-resolution microscopy, which is so far difficult to achieve.

Aims and Objectives: To derive new conceptual understanding about how women with rheumatoid arthritis manage their illness, motherhood and paid work, based on a comprehensive overview of existing knowledge, gained from qualitative studies., Background: Rheumatoid arthritis affects several social aspects of life; however, little is known about how women with rheumatoid arthritis simultaneously manage their illness, motherhood and paid work., Design: Qualitative metasynthesis., Methods: A qualitative metasynthesis informed by Noblit and Hare's meta-ethnography was carried out, based on studies identified by a systematic search in nine databases., Results: Six studies were included. Social interactions in the performance of three interdependent subidentities emerged as an overarching category, with three subcategories: subidentities associated with (1) paid work, (2) motherhood and (3) rheumatoid arthritis. Pressure in managing one of the subidentities could restrict the fulfilment of the others. The subidentities were interpreted as being flexible, situational, contextual and competing. The women strove to construct meaningful subidentities by taking into account feedback obtained in social interactions., Conclusions: The subidentities associated with paid work and motherhood are competing subidentities. Paid work is given the highest priority, followed by motherhood and illness is the least attractive subidentity. Because of the fluctuating nature of the illness, the women constantly reconstruct the three interdependent subidentities., Relevance to Clinical Practice: When healthcare professionals meet a woman with rheumatoid arthritis, they should consider that she might not accept the subidentity as an ill person. Health professionals should not expect that women will prioritise their illness in their everyday life. This could be included in clinical conversation with the women., (© 2017 John Wiley & Sons Ltd.)