RTN3 and RTN4: Architects of SARS-CoV-2 replication organelles.

SARS-CoV-2 depends on host proteins for successful replication. In this issue, Williams et al. (2023. J. Cell Biol.https://doi.org/10.1083/jcb.202203060) report that the ER membrane-modulating proteins RTN3 and RTN4 are required for the formation of SARS-CoV-2 replication organelles via direct interaction with viral proteins NSP3 and NSP4

The Applicability of Photovoice in Pseudo-total Institutions – Methodological Insights From an Exploratory Study on Physical Activity in Nursing Homes

Photovoice helps participants express their perspectives through photography. As a setting for Photovoice, nursing homes represent challenging, yet promising, contexts partly characterized by elements of Goffman’s concept of “total institutions” and more fully characterized as Heinzelmann’s “pseudo-total institutions.” We analyzed Photovoice’s applicability in nursing homes within the context of physical activity promotion research. Our results indicate Photovoice (1) helps overcome fear and builds trust between researchers and participants, (2) requires certain ethical considerations, (3) addresses technical alienation, (4) determines what is relevant from participants’ point of view, and (5) points out the invisibility of significant others. Further, we provide insights for (6) making Photovoice research a priority in organizational routines, (7) contextualizing photographs, and (8) adjusting for COVID19-related methodological challenges. We also discuss our insights for potential adaptations to ensure participant privacy and safety when using Photovoice in pseudo-total institutions, such as nursing homes. Photovoice reveals activity-promoting and activity-impeding factors possibly unrecognized with other research methods, as well as differences in stakeholder perspectives about physical activity

In-situ investigations of structural changes during cyclic loading by high resolution reciprocal space mapping

A major failure reason for structural materials is fatigue-related damage due to repeatedly changing mechanical loads. During cyclic loading dislocations self-organize into characteristic ordered structures, which play a decisive role for the materials lifetime. These heterogeneous dislocation structures can be identified using advanced electron microscopy and synchrotron techniques. A detailed characterization of the microstructure during cyclic loading by in-situ monitoring the internal structure within individual grains with high energy x-rays can help to understand and predict the materials behavior during cyclic deformation and to improve the material design. While monitoring macroscopic stress and strain during cyclic loading, reciprocal space maps of diffraction peaks from single grains are obtained with high resolution. High Resolution Reciprocal Space Mapping was applied successfully in-situ during cyclic deformation of macroscopic aluminium samples at the Advanced Photon Source to reveal the structural reorganization within single grains embedded in the bulk material during fatigue

Monitoring microstructural evolution in-situ during cyclic deformation by high resolution reciprocal space mapping

The recently developed synchrotron technique High Resolution Reciprocal Space Mapping (HRRSM) is used to characterize the deformation structures evolving during cyclic deformation of commercially pure, polycrystalline aluminium AA1050. Insight into the structural reorganization within single grains is gained by in-situ monitoring of the microstructural evolution during cyclic deformation. By HRRSM, a large number of individual subgrains can be resolved within individual grains in the bulk of polycrystalline specimens and their fate, their individual orientation and elastic stresses, tracked during different loading regimes as tension and compression. With this technique, the evolution of dislocation structures in selected grains was followed during an individual load cycle

Human CD27+ Memory B Cells Colonize a Superficial Follicular Zone in the Palatine Tonsils With Similarities to the Spleen. A Multicolor Immunofluorescence Study of Lymphoid Tissue

Background: Memory B cell (mBC) induction and maintenance is one of the keys to long-term protective humoral immunity. MBCs are fundamental to successful medical interventions such as vaccinations and therapy in autoimmunity. However, their lifestyle and anatomic residence remain enigmatic in humans. Extrapolation from animal studies serves as a conceptual basis but might be misleading due to major anatomical distinctions between species. Methods and findings: Multicolor immunofluorescence stainings on fixed and unfixed frozen tissue sections were established using primary antibodies coupled to haptens and secondary signal amplification. The simultaneous detection of five different fluorescence signals enabled the localization and characterization of human CD27+CD20+Ki67- mBCs for the first time within one section using laser scanning microscopy. As a result, human tonsillar mBCs were initially identified within their complex microenvironment and their relative location to naïve B cells, plasma cells and T cells could be directly studied and compared to the human splenic mBC niche. In all investigated tonsils (n = 15), mBCs appeared to be not only located in a so far subepithelial defined area but were also follicle associated with a previous undescribed gradual decline towards the follicular mantle comparable to human spleen. However, mBC areas around secondary follicles with large germinal centers (GCs) in tonsils showed interruptions and a general widening towards the epithelium while in spleen the mBC-containing marginal zones (MZ) around smaller GCs were relatively broad and symmetrical. Considerably fewer IgM+IgD+/- pre-switch compared to IgA+ or IgG+ post-switch mBCs were detected in tonsils in contrast to spleen. Conclusions: This study extends existing insights into the anatomic residence of human mBCs showing structural similarities of the superficial follicular area in human spleen and tonsil. Our data support the debate of renaming the human splenic MZ to 'superficial zone' in order to be aware of the differences in rodents and, moreover, to consider this term equally for the human palatine tonsil

Saving lives through life-threatening measures? The COVID-19 paradox of infection prevention in long-term care facilities [commentary].

The current SARS Cov-2 infection control measures have paradoxical effects. On the one hand, the lockdown measures help to protect vulnerable populations in particular. On the other hand, these measures inevitably have the effect that those who are to be protected not only become socially isolated and are exposed to enormous psychological stress, but also break down physically due to inactivity. Thus, the activation that is omitted in the lockdown is not compensated by external reference groups, which also indicates that important conditions for healthy ageing are not given in long-term care facilities

Comparison of Habitual and Maximal Gait Speed and their Impact on Sarcopenia Quantification in German Nursing Home Residents.

OBJECTIVES Sarcopenia is characterized by loss of muscle strength and muscle mass. The EWGSOP2 specifications include physical functioning determination for quantification of the sarcopenia severity. However, there is a lack in the use of habitual and maximal gait speed and their influence on sarcopenia quantification. We hypothesize differences in sarcopenia quantification using habitual and maximal gait speed. METHODS Sixty-six residents from five nursing homes were examined. Habitual and maximal gait speed were measured by 4-meter-walking-Test. McNemar-Test and χ2-test were used to identify quantification differences. Effect sizes of both gait speeds were calculated with Spearman's rank-correlation-coefficient. RESULTS Significant difference was identified for twenty-two residents in physical functioning classification by McNemar-Test (p<.001). χ2-Test identified a significant frequency distribution for sarcopenia categories between both gait speeds (χ2 (df2)=11.215, p=.004; Cramer's V=.412). Significant correlations (p<.05) were only shown for maximal gait speed in variables falls in the last three months (|rs|=.326), Barthel-Index (|rs|=.415), and SARC-F (|rs|=.335). CONCLUSIONS The use of habitual and maximal gait speed has a significant impact on sarcopenia quantification in nursing home residents. An adapted standardization in the EWGSOP2 specifications should follow