Search

Introduction: Monitoring of bone mineral density (BMD) is used to assess pharmacological osteoporosis therapy. This study examined the real-life effects of antiresorptive and osteoanabolic treatments on volumetric BMD (vBMD) of the spine by quantitative computed tomography (QCT)., Materials and Methods: Patients aged ≥ 50 years with a vBMD < 120 mg/ml had ≥ 2 QCT. For analysis of therapy effects, the pharmacological treatment and the duration of each therapy were considered. Identical vertebrae were evaluated in all vBMD measurements for each patient. A linear mixed model with random intercepts was used to estimate the effects of pharmacological treatments on vBMD., Results: A total of 1145 vBMD measurements from 402 patients were analyzed. Considering potential confounders such as sex, age, and prior treatment, a reduction in trabecular vBMD was estimated for oral bisphosphonates (- 1.01 mg/ml per year; p < 0.001), intravenous bisphosphonates (- 0.93 mg/ml per year; p = 0.015) and drug holiday (- 1.58 mg/ml per year; p < 0.001). Teriparatide was estimated to increase trabecular vBMD by 4.27 mg/ml per year (p = 0.018). Patients receiving denosumab showed a statistically non-significant decrease in trabecular vBMD (- 0.44 mg/ml per year; p = 0.099). Compared to non-treated patients, pharmacological therapy had positive effects on trabecular vBMD (1.35 mg/ml; p = 0.001, 1.43 mg/ml; p = 0.004, 1.91 mg/ml; p < 0.001, and 6.63 mg/ml; p < 0.001 per year for oral bisphosphonates, intravenous bisphosphonates, denosumab, and teriparatide, respectively)., Conclusion: An increase in trabecular vBMD by QCT was not detected with antiresorptive agents. Patients treated with teriparatide showed increasing trabecular vBMD. Non-treatment led to a larger decrease in trabecular vBMD than pharmacological therapy., (© 2024. The Japanese Society Bone and Mineral Research.)

Phaeochromocytomas (PC) and paragangliomas (PG) are neural crest cancers with high heritability. Recent advances in molecular profiling, including multi-omics and single cell genomics has identified up to seven distinct molecular subtypes. These subtypes are defined by mutations involving hypoxia-inducible factors (HIFs), Krebs cycle, kinase and WNT signalling, but are also defined by chromaffin differentiation states. PCPG have a dominant proangiogenic microenvironment linked to HIF pathway activity and are generally considered "immune cold" tumours with a high number of macrophages. PCPG subtypes can indicate increased metastatic risk but secondary mutations in telomere maintenance genes TERT or ATRX are required to drive the metastatic phenotype. Molecular profiling can identify molecular therapeutic (e.g. RET and EPAS1) and radiopharmaceutical targets while also helping to support variant pathogenicity and familial risk. Molecular profiling and subtyping of PCPG therefore confers the possibility of nuanced prognostication and individual treatment stratification but this still requires large-scale prospective validation., (Copyright © 2024. Published by Elsevier Ltd.)

Background: To date, long-term results of the arthroscopic repair of glenoid rim fractures are missing. The aim of this study was, to evaluate clinical and radiographic results following arthroscopic repair of anteroinferior glenoid fractures using anchors or bioabsorbable compression screws after a mean follow-up period of ten years., Methods: Clinical outcome measures included evaluation of recurrent instability, the Constant Score (CS), Subjective Shoulder Value (SSV), Rowe Score (RS), Western Ontario Shoulder Instability Score (WOSI) and Melbourne Instability Shoulder Score (MISS). X-ray images were obtained for assessment of an instability arthropathy (IA)., Results: 23 patients (7 female and 16 male, mean (± SD) age 48 ± 15 years) who underwent arthroscopic repair of an acute substantial solitary or multifragmented anteroinferior glenoid rim fracture were enrolled. After a mean follow-up period of 10 ± 2 years, patients reached a mean CS of 92 ± 10 points, SSV of 93 ± 11%, RS of 84 ± 20 points, WOSI of 98 ±2% and MISS of 91 ± 11 points. No patient suffered recurrent dislocation. Radiographic results were obtained of 18 patients. Signs of IA were noted in nine patients (50%) with progression of IA in all cases in comparison to the preoperative status. Patients with IA were significantly older (52 versus 38 years, p = 0.04). Clinical score results did not show a significant difference in patients with versus without IA except for the RS (74 versus 94 points, p = 0.02). No intra- or postoperative complications were observed, and no patient required revision endoprosthetic surgery., Conclusion: Arthroscopic repair of acute anteroinferior glenoid rim fractures shows good clinical long-term results. High rates of IA were observed especially in older patients. However, the presence of IA did not seem to influence the subjective shoulder score outcomes., (Copyright © 2024. Published by Elsevier Inc.)

Background: Smallpox was a major cause of human mortality until its eradication, but the threat of orthopox viruses has not disappeared. Since the eradication of smallpox and the cessation of the related vaccination campaigns, the threat has been growing, as evidenced by the currently ongoing worldwide Mpox outbreak. In addition to threats of an evolving Mpox, we must also be aware of a myriad of other threats that remain. Many countries still lack biosecurity regulations reflecting the recent technological advances, and the threat of bioterrorism remains ever present. Reconstruction of smallpox is a distinct possibility, as are other scenarios whereby other orthopox viruses may be made more fit for transmission in humans., Objectives: To outline and discuss potential biosafety and biosecurity threats posed by orthopox viruses., Sources: Published scientific literature, news articles, and international agreements., Content and Implications: It would be wise to take steps to mitigate these threats now. Vaccination campaigns should be considered in areas with frequent orthopox outbreaks, and more efforts must be made to put a final end to the Mpox outbreak. In many countries, national biosafety and biosecurity regulations may need to be revised and strengthened to better reflect the threats posed by new technologies, including controls on synthesis of smallpox sequences. Furthermore, more international cooperation and aid is needed. The present global Mpox outbreak could likely have been prevented had areas where Mpox is endemic not been neglected. Future outbreaks could be much worse., (Copyright © 2024 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Hereditary SDHB -mutant pheochromocytomas (PC) and paragangliomas (PG) are rare tumours with a high propensity to metastasize although their clinical behaviour is unpredictable. To characterize the genomic landscape of these tumours and identify metastasis biomarkers, we performed multi-omic analysis on 94 tumours from 79 patients using seven molecular methods. Sympathetic (chromaffin cell) and parasympathetic (non-chromaffin cell) PCPG had distinct molecular profiles reflecting their cell-of-origin and biochemical profile. TERT and ATRX -alterations were associated with metastatic PCPG and these tumours had an increased mutation load, and distinct transcriptional and telomeric features. Most PCPG had quiet genomes with some rare co-operative driver events observed, including EPAS1 /HIF-2α mutations. Two mechanisms of acquired resistance to DNA alkylating chemotherapies were also detected - MGMT overexpression and mismatch repair-deficiency causing hypermutation. Our comprehensive multi-omic analysis of SDHB -mutant PCPG therefore identified features of metastatic disease and treatment response, expanding our understanding of these rare neuroendocrine tumours., Competing Interests: Competing interests The authors declare no competing interests.

Objectives: To determine all-cause in-hospital mortality associated with severe hypernatraemia and the causes, comorbidities, time to treatment, discharge destination and postdischarge mortality., Design: Retrospective observational cohort study., Patients: Severe hypernatraemia, (sodium concentration ≥ 155 mmol/L), at any time during a tertiary hospital admission in Melbourne, Australia, 1 January 2019 to 31 December 2019 (pre-COVID19)., Measurements: Deaths, Charlson Comorbidity Index (CCI), hypernatraemia causes, time to treatment, discharge destination., Results: One hundred and one inpatients: 64 community-acquired, 37 hospital-acquired. In-hospital mortality was 38%, but cumulative mortality was 65% by 1 month after discharge, with only a minor further increase at 6 and 12 months. After adjusting for peak sodium concentration, the community acquired group had significantly reduced odds of in-hospital mortality (odds ratio 0.15, 95% confidence interval [0.04-0.54], p = .003). Iatrogenic factors were present in 57% (21/37) of the hospital-acquired group. Only 55% of all cases received active sodium directed treatment. Time to start treatment did not affect outcomes. High levels of comorbidity were present, median CCI (IQR) was 6 (5-8) in the community and 5 (4-7) in the hospital group. Dementia prevalence was higher in the community group, 66% (42/64) versus 19% (7/37) (p = .001). Infection was the most common precipitant with 52% (33/64) in the community and 32% (12/37) in the hospital group. Of the survivors, 32% who had been living independently required residential care after discharge., Conclusions: Mortality was high and loss of independence in survivors common. To potentially improve outcomes, hypernatraemia-specific guidelines should be formulated and efforts made to reduce system and iatrogenic factors., (© 2023 The Authors. Clinical Endocrinology published by John Wiley & Sons Ltd.)

Introduction: Dual-energy X-ray absorptiometry (DXA) is considered the gold standard for the diagnosis of osteoporosis and assessment of fracture risk despite proven limitations. Quantitative computed tomography (QCT) is regarded as a sensitive method for diagnosis and follow-up. Pathologic fractures are classified as the main clinical manifestation of osteoporosis. The objective of the study was to compare DXA and QCT to determine their sensitivity and discriminatory power., Materials and Methods: Patients aged 50 years and older were included who had DXA of the lumbar spine and femur and additional QCT of the lumbar spine within 365 days. Fractures and bone mineral density (BMD) were retrospectively examined. BMD measurements were analyzed for the detection of osteoporotic fractures. Sensitivity and receiver operating characteristic curve were used for calculations. As an indication for a second radiological examination was given, the results were compared with control groups receiving exclusively DXA or QCT for diagnosis or follow-up., Results: Overall, BMD measurements of 404 subjects were analyzed. DXA detected 15 (13.2%) patients having pathologic fractures (n = 114) with normal bone density, 66 (57.9%) with osteopenia, and 33 (28.9%) with osteoporosis. QCT categorized no patients having pathologic fractures with healthy bone density, 14 (12.3%) with osteopenia, and 100 (87.7%) with osteoporosis. T-score DXA, trabecular BMD QCT, and cortical BMD QCT correlated weakly. Trabecular BMD QCT and cortical BMD QCT classified osteoporosis with decreased bone mineral density (AUC 0.680; 95% CI 0.618-0.743 and AUC 0.617; 95% CI 0.553-0.682, respectively). T-score DXA could not predict prevalent pathologic fractures. In control groups, each consisting of 50 patients, DXA and QCT were significant classifiers to predict prevalent pathologic fractures., Conclusion: Our results support that volumetric measurements by QCT in preselected subjects represent a more sensitive method for the diagnosis of osteoporosis and prediction of fractures compared to DXA., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Cannabis-based biomaterials have the potential to deliver anti-inflammatory therapeutics specifically to desired cells, tissues, and organs, enhancing drug delivery and the effectiveness of anti-inflammatory treatment while minimizing toxicity. As a major component of Cannabis, Cannabidiol (CBD) has gained major attention in recent years because of its potential therapeutic properties, e.g., for restoring a disturbed barrier resulting from inflammatory conditions. The aim of this study was to test the hypothesis that CBD has beneficial effects under normal and inflammatory conditions in the established non-transformed intestinal epithelial cell model IPEC-J2. CBD induced a significant increase in transepithelial electrical resistance (TER) values and a decrease in the paracellular permeability of [³H]-D-Mannitol, indicating a strengthening effect on the barrier. Under inflammatory conditions induced by tumor necrosis factor alpha (TNFα), CBD stabilized the TER and mitigated the increase in paracellular permeability. Additionally, CBD prevented the barrier-disrupting effects of TNFα on the distribution and localization of sealing TJ proteins. CBD also affected the expression of TNF receptors. These findings demonstrate the potential of CBD as a component of Cannabis-based biomaterials used in the development of novel therapeutic approaches against inflammatory pathogenesis., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Anterior glenohumeral instability is the most frequent type of shoulder instability. This is often associated with labral and osseous lesions leading to recurrent instability. A detailed medical history, a physical examination and targeted diagnostic imaging are necessary to assess possible pathological soft tissue alterations as well as bony lesions of the humeral head and the glenoid bone. Early surgical treatment has been shown to reduce the risk of recurrence, especially in young active athletes, and can avoid secondary damage. Shoulder dislocations in older patients also require a detailed assessment and selection of treatment as persisting pain and limitation of movement can occur due to rotator cuff lesions and nerve injuries. The purpose of this article is to provide an overview of the currently available evidence and results regarding diagnostic considerations and conservative vs. surgical treatment and time to return to sport after treatment of a primary anterior shoulder dislocation., (© 2023. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Purpose of Review: Gastroenteropancreatic NEN (GEP-NEN) are group of malignancies with significant clinical, anatomical and molecular heterogeneity. High-grade GEP-NEN in particular present unique management challenges., Recent Findings: In the current era, multidisciplinary management with access to a combination of functional imaging and targeted molecular profiling can provide important disease characterisation, guide individualised management and improve patient outcome. Multiple treatment options are now available, and combination and novel therapies are being explored in clinical trials. Precision medicine is highly relevant for a heterogenous disease like NEN. The integration of dual-tracer functional PET/CT imaging, molecular histopathology and genomic data has the potential to be used to gain a more comprehensive understanding of an individual patient's disease biology for precision diagnosis, prognostication and optimal treatment allocation., (© 2023. Crown.)

Objective: The purpose of this study was to assess the reliability and educational quality of content available on Google and YouTube regarding subacromial impingement syndrome (SAIS)., Methods: Google and YouTube were queried for English and German results on SAIS using the search terms "shoulder impingement" and the German equivalent "Schulter Impingement". The analysis was restricted to the first 30 results of each query performed. Number of views and likes as well as upload source and length of content were recorded. Each result was evaluated by two independent reviewers using the Journal of the American Medical Association (JAMA) benchmark criteria (score range, 0-5) to assess reliability and the DISCERN score (score range, 16-80) and a SAIS-specific score (SAISS, score range, 0-100) to evaluate educational content., Results: The 58 websites found on Google and 48 videos found on YouTube were included in the analysis. The average number of views per video was 220,180 ± 415,966. The average text length was 1375 ± 997 words and the average video duration 456 ± 318 s. The upload sources were mostly non-physician based (74.1% of Google results and 79.2% of YouTube videos). Overall, there were poor results in reliability and educational quality, with sources from doctors having a significantly higher mean reliability measured in the JAMA score (p < 0.001) and educational quality in DISCERN (p < 0.001) and SAISS (p = 0.021). There was no significant difference between German and English results but texts performed significantly better than videos in terms of reliability (p = 0.002) and educational quality (p < 0.001)., Conclusion: Information on SAIS found on Google and YouTube is of low reliability and quality. Therefore, orthopedic health practitioners and healthcare providers should inform patients that this source of information may be unreliable and make efforts to provide patients with higher quality alternatives., Level of Evidence: IV, case series., (© 2022. The Author(s).)

Satellite glia are the major glial cells in sympathetic ganglia, enveloping neuronal cell bodies. Despite this intimate association, the extent to which sympathetic functions are influenced by satellite glia in vivo remains unclear. Here, we show that satellite glia are critical for metabolism, survival, and activity of sympathetic neurons and modulate autonomic behaviors in mice. Adult ablation of satellite glia results in impaired mTOR signaling, soma atrophy, reduced noradrenergic enzymes, and loss of sympathetic neurons. However, persisting neurons have elevated activity, and satellite glia-ablated mice show increased pupil dilation and heart rate, indicative of enhanced sympathetic tone. Satellite glia-specific deletion of Kir4.1, an inward-rectifying potassium channel, largely recapitulates the cellular defects observed in glia-ablated mice, suggesting that satellite glia act in part via K + -dependent mechanisms. These findings highlight neuron-satellite glia as functional units in regulating sympathetic output, with implications for disorders linked to sympathetic hyper-activity such as cardiovascular disease and hypertension., Competing Interests: AM, EB, CB, WK, JL, ML, MT, SH, HZ, ET, RK No competing interests declared

Background: The modern era of radioiodine (I-131) theranostics for metastatic differentiated thyroid cancer requires us to rationalize the role of traditional empiric prescription in nonmalignant thyroid disease. We currently practice empiric I-131 prescription for treatment of hyperthyroidism. This study aims to assess outcomes after treatment of hyperthyroidism by empiric I-131 prescription at our centre, evaluate factors that impact on outcomes and prescribing practice, and gain insight into whether there is a place for theranostically-guided prescription in hyperthyroidism., Patients and Methods: A retrospective review was undertaken of all patients with Graves' disease, toxic multinodular goitre (MNG) and toxic adenoma treated with I-131 between 2016 and 2021. Associations between clinical or scintigraphic variables and remission (euthyroid or hypothyroid) or persistence of hyperthyroidism at follow-up were performed using standard t test as well as Pearson's product correlation., Results: Of 146 patients with a mean follow-up of 13.6 months, 80.8% achieved remission of hyperthyroidism. This was highest in toxic nodules (90.1%), compared with Graves' disease (73.8%) and toxic MNG (75.5%). In patients with Graves' disease, higher administered activity was associated with remission (p = .035). There was a weak inverse correlation between the Tc-99m pertechnetate uptake vs prescribed activity in Graves' disease (r = -0.33; p = .009). Only one patient (0.7%) had an I-131 induced flare of thyrotoxicosis., Conclusion: Traditional empiric I-131 prescription is a safe and effective treatment of hyperthyroidism and suitable for most patients. However, there may be a role for personalized I-131 prescription by theranostic guidance in selected patients with high thyroid hyperactivity., (© 2022 John Wiley & Sons Ltd.)

Transmission of influenza A viruses (IAV) between hosts is subject to numerous physical and biological barriers that impose genetic bottlenecks, constraining viral diversity and adaptation. The bottlenecks within hosts and their potential impacts on evolutionary pathways taken during infection are poorly understood. To address this, we created highly diverse IAV libraries bearing molecular barcodes on two gene segments, enabling high-resolution tracking and quantification of unique virus lineages within hosts. Here we show that IAV infection in lungs is characterized by multiple within-host bottlenecks that result in "islands" of infection in lung lobes, each with genetically distinct populations. We perform site-specific inoculation of barcoded IAV in the upper respiratory tract of ferrets and track viral diversity as infection spreads to the trachea and lungs. We detect extensive compartmentalization of discrete populations within lung lobes. Bottleneck events and localized replication stochastically sample individual viruses from the upper respiratory tract or the trachea that become the dominant genotype in a particular lobe. These populations are shaped strongly by founder effects, with limited evidence for positive selection. The segregated sites of replication highlight the jackpot-style events that contribute to within-host influenza virus evolution and may account for low rates of intrahost adaptation., (© 2022. The Author(s).)

The proinflammatory cytokine tumor necrosis factor (TNF) has been described as one of the main mediators of intestinal inflammatory diseases, affecting the composition of tight junction (TJ) proteins and leading to a disruption of the epithelial barrier. An intact intestinal barrier is mandatory, because the follicle-associated epithelium of Peyer's patches represents the first defense line of the intestinal immune system and ensures a controlled uptake of antigens from the gut lumen. In the current study, we have analyzed the detailed effects of TNF on the follicle-associated epithelium of porcine Peyer's patches by applying the Ussing chamber technique. Epithelial tissue specimens of Peyer's patches and the surrounding villus epithelium were mounted into conventional Ussing chambers and incubated with TNF for 10 h. The transepithelial resistance, representing epithelial barrier function of the tissue, was recorded. A reduction of transepithelial resistance was detected after 8 h in Peyer's patch tissue specimens, whereas the villus epithelium was not significantly affected by TNF. Subsequent molecular analysis of TJ protein expression revealed a marked decrease of claudin-1 and -4, and an increase of claudin-2. In neighboring villus epithelium, no significant changes in the expression of TJ proteins could be shown. A strong increase of TNF receptor-2 (TNFR-2) could also be detected in Peyer's patches, in agreement with the major role of this receptor in Peyer's patches. Our findings were in accordance with changes detected by confocal laser scanning immunofluorescence microscopy. The regulation of TNF effects via myosin light chain kinase (MLCK) was analyzed in blocking experiments. Our detailed analysis is the first to show that TNF affects the barrier function of the follicle-associated epithelium of porcine Peyer's patches but has no effects on the villus epithelium. These findings reveal not only the basic differences of epithelial barrier function between the two structures, but also the significance of Peyer's patches as a primary mucosal immune defense., 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 © 2022 Droessler, Cornelius, Boehm, Stein, Brunner and Amasheh.)

The plant alkaloid berberine has been shown to have many beneficial effects on human health. This has led to its use as a treatment for various cancer types, obesity, and diabetes. Moreover, a described barrier-strengthening effect in human cancer cell lines indicates that it might be useful for the treatment of inflammatory bowel disease. Detailed information regarding its effects on intestinal epithelium remains limited. In our current study, we describe the impact of berberine on a non-transformed porcine small intestinal epithelial cell model, IPEC-J2. Incubation of IPEC-J2 monolayers with berberine revealed dose- and time-dependent effects on barrier properties. A viability assay confirmed the specific effect of berberine on the apoptotic pathway, paralleled by the internalization of the sealing tight-junction (TJ) proteins claudin-1, claudin-3, and occludin within 6 h. Hence, the barrier function of the cells was reduced, as shown by the reduced transepithelial electrical resistance and the increased [ 3 H]-D-Mannitol flux. A decrease of claudin-1, claudin-3, and occludin expression was also observed after 24 h, whereas ZO-1 expression was not significantly changed. These data indicate an early effect on both cell viability and barrier integrity, followed by a general effect on TJ architecture. The intracellular co-localization of claudin-1 and occludin or claudin-3 and occludin points to an initial induction of apoptosis accompanied by the internalization of sealing TJ proteins. Although barrier strengthening has been reported in cancerogenic epithelial models, our results show a barrier-weakening action, which represents a new aspect of the effect of berberine on epithelia. These results agree with the known toxic potential of plant alkaloids in general and show that berberine is also capable of exerting adverse effects in the intestinal epithelium., (© 2022 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)

Satellite glia are the major glial type found in sympathetic and sensory ganglia in the peripheral nervous system, and specifically, contact neuronal cell bodies. Sympathetic and sensory neurons differ in morphological, molecular, and electrophysiological properties. However, the molecular diversity of the associated satellite glial cells remains unclear. Here, using single-cell RNA sequencing analysis, we identify five different populations of satellite glia from sympathetic and sensory ganglia. We define three shared populations of satellite glia enriched in immune-response genes, immediate-early genes, and ion channels/ECM-interactors, respectively. Sensory- and sympathetic-specific satellite glia are differentially enriched for modulators of lipid synthesis and metabolism. Sensory glia are also specifically enriched for genes involved in glutamate turnover. Furthermore, satellite glia and Schwann cells can be distinguished by unique transcriptional signatures. This study reveals the remarkable heterogeneity of satellite glia in the peripheral nervous system., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2022. Published by Elsevier Inc.)

Risk-benefit Assessment (RBA) is an emerging methodology in the area of Food and Nutrition that offers a simultaneous evaluation of both risks and benefits linked to dietary choices. Communication of such research to consumers may present a challenge due to the dual nature of RBA. We present a case study of a communication strategy developed for the NovRBA-project. The NovRBA-project (Novel foods as red meat replacers-an insight using Risk Benefit Assessment methods) performed a risk-benefit assessment to evaluate the overall health impact of substituting red meat (beef) by a novel food (house cricket), considering the microbial, toxicological and nutritional characteristics of the respective dietary choices. A literature review of risk perceptions and acceptance of beef and insects as food formed the basis of the communication strategy for the study's results, drawing on environmental and emotional as well as health-related motivations to consume or avoid either food and considering the sociodemographic characteristics of likely consumers. Challenges and future directions for consumer protection organizations communicating findings of risk-benefit analyses on food safety are discussed., 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. The reviewer CP declared a shared affiliation with one of the authors EV to the handling editor at the time of review., (Copyright © 2021 Boehm, Borzekowski, Ververis, Lohmann and Böl.)

The sympathetic nervous system prepares the body for 'fight or flight' responses and maintains homeostasis during daily activities such as exercise, eating a meal or regulation of body temperature. Sympathetic regulation of bodily functions requires the establishment and refinement of anatomically and functionally precise connections between postganglionic sympathetic neurons and peripheral organs distributed widely throughout the body. Mechanistic studies of key events in the formation of postganglionic sympathetic neurons during embryonic and early postnatal life, including axon growth, target innervation, neuron survival, and dendrite growth and synapse formation, have advanced the understanding of how neuronal development is shaped by interactions with peripheral tissues and organs. Recent progress has also been made in identifying how the cellular and molecular diversity of sympathetic neurons is established to meet the functional demands of peripheral organs. In this Review, we summarize current knowledge of signalling pathways underlying the development of the sympathetic nervous system. These findings have implications for unravelling the contribution of sympathetic dysfunction stemming, in part, from developmental perturbations to the pathophysiology of peripheral neuropathies and cardiovascular and metabolic disorders., (© 2021. Springer Nature Limited.)

Background: Many new variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been termed variants of concern/interest (VOC/I) because of the greater risk they pose due to possible enhanced transmissibility and/or severity, immune escape, diagnostic and/or treatment failure, and reduced vaccine efficacy., Aims: We sought to review the current knowledge of emerging SARS-CoV-2 variants, particularly those deemed VOC/Is: B.1.351, B.1.1.7, and P.1., Sources: MEDLINE and BioRxiv databases, as well as the grey literature, were searched for reports of SARS-CoV-2 variants since November 2020. Relevant articles and their references were screened., Content: Mutations on the spike protein in particular may affect both affinity for the SARS-CoV-2 cell receptor ACEII and antibody binding. These VOC/Is often share similar mutation sets. The N501Y mutation is shared by the three main VOCs: B.1.1.7, first identified in the United Kingdom, P.1, originating from Brazil, and B.1.351, first described in South Africa. This mutation likely increases transmissibility by increasing affinity for ACEII. The B.1.351 and P.1 variants also display the E484K mutation which decreases binding of neutralizing antibodies, leading to partial immune escape; this favours reinfections, and decreases the in vitro efficacy of some antibody therapies or vaccines. Those mutations may also have phenotypical repercussions of greater severity. Furthermore, the accumulation of mutations poses a diagnostic risk (lowered when using multiplex assays), as seen for some assays targeting the S gene. With ongoing surveillance, many new VOC/Is have been identified. The emergence of the E484K mutation independently in different parts of the globe may reflect the adaptation of SARS-CoV-2 to humans against a background of increasing immunity., Implications: These VOC/Is are increasing in frequency globally and pose challenges to any herd immunity approach to managing the pandemic. While vaccination is ongoing, vaccine updates may be prudent. The virus continues to adapt to transmission in humans, and further divergence from the initial Wuhan sequences is expected., (Copyright © 2021 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Background: Antigen-detecting rapid diagnostic tests (Ag-RDTs) for the detection of SARS-CoV-2 offer new opportunities for testing in the context of the COVID-19 pandemic. Nasopharyngeal swabs (NPS) are the reference sample type, but oropharyngeal swabs (OPS) may be a more acceptable sample type in some patients., Methods: We conducted a prospective study in a single screening center to assess the diagnostic performance of the Panbio™ COVID-19 Ag Rapid Test (Abbott) on OPS compared with reverse-transcription quantitative PCR (RT-qPCR) using NPS during the second pandemic wave in Switzerland., Results: 402 outpatients were enrolled in a COVID-19 screening center, of whom 168 (41.8%) had a positive RT-qPCR test. The oropharyngeal Ag-RDT clinical sensitivity compared to nasopharyngeal RT-qPCR was 81% (95%CI: 74.2-86.6). Two false positives were noted out of the 234 RT-qPCR negative individuals, which resulted in a clinical specificity of 99.1% (95%CI: 96.9-99.9) for the Ag-RDT. For cycle threshold values ≤ 26.7 (≥ 1E6 SARS-CoV-2 genomes copies/mL, a presumed cut-off for infectious virus), 96.3% sensitivity (95%CI: 90.7-99.0%) was obtained with the Ag-RDT using OPS., Interpretation: Based on our findings, the diagnostic performance of the Panbio™ Covid-19 RDT with OPS samples, if taken by a trained person and high requirements regarding quality of the specimen, meet the criteria required by the WHO for Ag-RDTs (sensitivity ≥80% and specificity ≥97%) in a high incidence setting in symptomatic individuals., Competing Interests: The authors have declared that no competing interests exist.

Extended community testing constitutes one of the main strategic pillars in controlling the COVID-19 pandemic. Reverse transcription PCR (RT-PCR) targeting the SARS-CoV-2 genome on nasopharyngeal swab samples is currently the reference test. While displaying excellent analytical sensitivity and specificity, this test is costly, often requires a substantial turnaround time, and, more importantly, is subject to reagent and other material shortages. To complement this technology, rapid antigen tests have been developed and made available worldwide, allowing cheap, quick, and decentralized SARS-CoV-2 testing. The main drawback of these tests is the reduced sensitivity when RT-PCR is the gold standard. In this study, we evaluate Visby an innovative, portable, easy-to-use RT-PCR point-of-care (POC) diagnostic device. Our retrospective analysis shows that overall, compared to the Cobas 6800 RT-qPCR assay (Roche), this RT-PCR POC technology detects SARS-CoV-2 RNA with 95% sensitivity (95%CI = 86.3-99%) and 100% specificity (95% CI = 80.5-100%). For samples with cycle-threshold values below 31, we observed 100% sensitivity (95% CI = 66.4-100%). While showing an analytical sensitivity slightly below that of a standard RT-qPCR system, the evaluated Visby RT-PCR POC device may prove to be an interesting diagnostic alternative in the COVID-19 pandemic, potentially combining the practical advantages of rapid antigen tests and the robust analytical performances of nucleic acid detection systems.

Objectives: Determine the diagnostic accuracy of two antigen-detecting rapid diagnostic tests (Ag-RDT) for SARS-CoV-2 at the point of care and define individuals' characteristics providing best performance., Methods: We performed a prospective, single-center, point of care validation of two Ag-RDT in comparison to RT-PCR on nasopharyngeal swabs., Results: Between October 9th and 23rd, 2020, 1064 participants were enrolled. The PanbioTM Covid-19 Ag Rapid Test device (Abbott) was validated in 535 participants, with 106 positive Ag-RDT results out of 124 positive RT-PCR individuals, yielding a sensitivity of 85.5% (95% CI: 78.0-91.2). Specificity was 100.0% (95% CI: 99.1-100) in 411 RT-PCR negative individuals. The Standard Q Ag-RDT (SD Biosensor, Roche) was validated in 529 participants, with 170 positive Ag-RDT results out of 191 positive RT-PCR individuals, yielding a sensitivity of 89.0% (95%CI: 83.7-93.1). One false positive result was obtained in 338 RT-PCR negative individuals, yielding a specificity of 99.7% (95%CI: 98.4-100). For individuals presenting with fever 1-5 days post symptom onset, combined Ag-RDT sensitivity was above 95%. Lower sensitivity of 88.2% was seen on the same day of symptom development (day 0)., Conclusions: We provide an independent validation of two widely available commercial Ag-RDTs, both meeting WHO criteria of ≥80% sensitivity and ≥97% specificity. Although less sensitive than RT-PCR, these assays could be beneficial due to their rapid results, ease of use, and independence from existing laboratory structures. Testing criteria focusing on patients with typical symptoms in their early symptomatic period onset could further increase diagnostic value., Competing Interests: The authors have declared that no competing interests exist.

Purpose: To investigate the clinical and radiologic mid- to long-term results of arthroscopic iliac crest bone-grafting for anatomic glenoid reconstruction in patients with recurrent anterior shoulder instability., Methods: Seventeen patients were evaluated after a minimum follow-up of 5 years. Clinical [range of motion, subscapularis tests, apprehension sign, Subjective Shoulder Value (SSV), Constant Score (CS), Rowe Score (RS), Walch Duplay Score (WD), Western Ontario Shoulder Instability Index (WOSI)], and radiologic [X-ray (true a.p., Bernageau and axillary views) and computed tomography (CT)] outcome parameters were assessed., Results: Fourteen patients [mean age 31.1 (range 18-50) years] were available after a follow-up period of 78.7 (range 60-110) months. The SSV averaged 87 (range 65-100) %, CS 94 (range 83-100) points, RS 89 (range 30-100) points, WD 87 (range 25-100) points, and WOSI 70 (range 47-87) %. The apprehension sign was positive in two patients (14%). One patient required an arthroscopic capsular plication due to a persisting feeling of instability, while the second patient experienced recurrent dislocations after a trauma, but refused revision surgery. CT imaging showed a significant increase of the glenoid index from preoperative 0.8 ± 0.04 (range 0.7-0.8) to 1.0 ± 0.11 (range 0.8-1.2) at the final follow-up (p < 0.01)., Conclusion: Arthroscopic reconstruction of anteroinferior glenoid defects using an autologous iliac crest bone-grafting technique yields satisfying clinical and radiologic results after a mid- to long-term follow-up period. Postoperative re-dislocation was experienced in one (7.1%) of the patients due to a trauma and an anatomic reconstruction of the pear-shaped glenoid configuration was observed., Level of Evidence: IV.

Background: Individual constitutional differences in glenoid shape and bone remodeling require a patient-specific and longitudinal approach to evaluate the biomechanical effects of glenoid bone grafting in patients with anterior shoulder instability., Purpose: To quantify the longitudinal, in vivo, biomechanical effects of bone grafting, bone graft remodeling, and glenoid shape in patients with anterior shoulder instability by means of patient-specific finite element models., Study Design: Descriptive laboratory study., Methods: In total, 25 shoulders of 24 patients with anterior shoulder instability and anterior glenoid bone loss underwent an arthroscopic iliac crest bone graft transfer (ICBGT) procedure with either autologous or allogenic bone. Patient-specific finite element simulations based on preoperative, postoperative, and follow-up computed tomography scans were used to quantify the bone-mediated stability ratio (SR) and the distance to dislocation. Additionally, the relationship between glenoid morphological parameters and the SR was assessed., Results: The ICBGT procedure significantly increased the SR and distance to dislocation in the 2-, 3-, and 4-o ' clock directions immediately after the surgical intervention ( P < .01) in both the autograft and the allograft groups. Although the SR and distance to dislocation decreased subsequently, autografts showed long-term effects on SR and dislocation distance in the 3-o'clock direction ( P < .01) and on SR in the 4-o'clock direction ( P < .01). Allografts showed no significant effect on SR and dislocation distance in long-term follow-up ( P > .05). Overall, glenoid retroversion as well as cavity depth predicted stability in all 4 dislocation directions, with glenoid cavity depth showing the highest correlation coefficients ( R = 0.71, 0.8, 0.73, and 0.7 for 2-, 3-, 4-, and 5-o'clock, respectively)., Conclusion: The autologous ICBGT procedure biomechanically improved anterior shoulder stability in long-term follow-up, whereas the use of allografts did not show any bone-mediated biomechanical effect at follow-up due to resorption. Furthermore, in addition to measurements of defect extent, the glenoid depth and version seem to be useful parameters to determine the biomechanical effect and need for glenoid bone grafting in patients with shoulder instability., Clinical Relevance: This study proposes the use of autologous bone grafts for a successful long-term stabilization effect. Additionally, this study proposes additional glenoid morphological measures to predict shoulder stability.

Introduction: Donor site morbidity constitutes the most prevalent source of complications during anatomic glenoid reconstruction. Therefore, the aim of this study was to evaluate the clinical and radiologic results of arthroscopic anatomic glenoid reconstruction using an allogenic, tricortical iliac crest bone graft for glenoid bone loss in recurrent anterior shoulder instability., Materials and Methods: Ten patients [one female/nine male, mean age 31.9 years (range, 26-40)] underwent allogenic iliac crest bone grafting and were evaluated clinically [range of motion, subscapularis tests, apprehension sign, Constant score (CS), Rowe score (RS), Walch-Duplay score (WD), Western Ontario Shoulder Instability Index (WOSI), Subjective Shoulder Value (SSV)] and radiographically [3-dimensional computed tomography (CT) scans]., Results: After 23.2 months, the CS averaged 90 points (range, 84-98), RS 83 points (range, 50-100), WD 81 points (range, 50-100), WOSI 72% (range, 41-86) and the SSV 83% (range, 70-95). All patients showed a free range of motion and intact subscapularis muscle function. The apprehension sign was positive in three patients (30%) with a recurrent subluxation in one patient (10%). The glenoid surface area increased significantly from 84.4% (range, 73.5-92.1) preoperatively to 118.4% (range, 105.6-131.2) after surgery, while the glenoid defect was significantly reduced from 16.2% (range, 9.2-26.5) to 0.6% (range, 0-1.6). One year postoperative, total resorption of the allografts was observed with a glenoid surface area of 86.6% (range, 76.4-98.0) and corresponding increase of the glenoid defect to 14.0% (range, 2.9-23.6)., Conclusion: Arthroscopic glenoid reconstruction using an iliac crest bone allograft achieves satisfactory clinical results and glenohumeral stability during a short-term follow-up. However, this procedure was not observed to accomplish an anatomic reconstruction of the glenoid concavity due to excessive graft resorption., Level of Evidence: Level IV, case series, therapeutic study.

The study of non-human primate thanatology has expanded dramatically in recent years as scientists seek to understand the evolutionary roots of human death concepts and practices. However, observations of how conspecifics respond to dead individuals are rare and highly variable. Mothers of several species of primate have been reported to carry and continue to interact with dead infants. Such interactions have been proposed to be related to maternal condition, attachment, environmental conditions or reflect a lack of awareness that the infant has died. Here, we tested these hypotheses using a dataset of cases of infant corpse carrying by chimpanzees in Gombe National Park, Tanzania ( n = 33), the largest dataset of such cases in chimpanzees. We found that mothers carried infant corpses at high rates, despite behavioural evidence that they recognize that death has occurred. Median duration of carriage was 1.83 days (interquartile range = 1.03-3.59). Using an information theoretic approach, we found no support for any of the leading hypotheses for duration of continued carriage. We interpret these data in the context of recent discussions regarding what non-human primates understand about death., Competing Interests: The authors declare no competing interests., (© 2020 The Authors.)

Background: Autologous chondrocyte implantation (ACI) constitutes an established treatment option for cartilage defects of the knee joint. Experience in the shoulder, however, is limited, and the management of cartilage defects remains a challenge. The purpose of this study was to evaluate the results after ACI with 3-dimensional spheroids of human autologous matrix-associated chondrocytes in the shoulder., Methods: Seven male patients (median age, 42.8 years [range, 18-55 years]) underwent ACI for symptomatic focal grade IV cartilage lesions of the humeral head by an open or arthroscopic approach. Clinical parameters (range of motion, visual analog scale score, Subjective Shoulder Value, Constant score, and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form score) and osteoarthritis grades were assessed. Arthroscopic re-evaluation was additionally performed in 5 patients., Results: After a median follow-up period of 32 months (range, 22-58 months), the median Subjective Shoulder Value was 95% (range, 70%-100%) compared with 60% (range, 30%-60%) preoperatively, the visual analog scale score was 0 at rest and was a median of 0 (range, 0-2) during exercise, the median Constant score was 95 points (range, 80-100 points), and the median American Shoulder and Elbow Surgeons score was 97 points (range, 90-100 points). The median preoperative size of the cartilage lesion was 3 cm 2 (range, 2.3-4.5 cm 2 ). Arthroscopically, complete coverage of the cartilage defect was observed in 4 cases whereas a circumferential residual defect of 0.25 cm 2 was found in 1 patient. Grade I osteoarthritis (Samilson and Prieto classification) was observed in 2 cases. One patient had postoperative adhesive capsulitis and required revision surgery., Conclusion: ACI using 3-dimensional spheroids of human autologous matrix-associated chondrocytes for treatment of grade IV articular cartilage lesions of the humeral head achieves satisfactory clinical results during a short- to mid-term follow-up period and leads to successful defect coverage with only minor radiologic degenerative changes. In this case series, ACI proved to constitute a viable treatment in the shoulder joint. However, in consideration of the 2-stage surgical design and the cost intensiveness of this procedure, the indication is restricted to young and active symptomatic patients in our practice., (Copyright © 2019 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Accurately identifying patients with high-grade serous ovarian carcinoma (HGSOC) who respond to poly(ADP-ribose) polymerase inhibitor (PARPi) therapy is of great clinical importance. Here we show that quantitative BRCA1 methylation analysis provides new insight into PARPi response in preclinical models and ovarian cancer patients. The response of 12 HGSOC patient-derived xenografts (PDX) to the PARPi rucaparib was assessed, with variable dose-dependent responses observed in chemo-naive BRCA1/2-mutated PDX, and no responses in PDX lacking DNA repair pathway defects. Among BRCA1-methylated PDX, silencing of all BRCA1 copies predicts rucaparib response, whilst heterozygous methylation is associated with resistance. Analysis of 21 BRCA1-methylated platinum-sensitive recurrent HGSOC (ARIEL2 Part 1 trial) confirmed that homozygous or hemizygous BRCA1 methylation predicts rucaparib clinical response, and that methylation loss can occur after exposure to chemotherapy. Accordingly, quantitative BRCA1 methylation analysis in a pre-treatment biopsy could allow identification of patients most likely to benefit, and facilitate tailoring of PARPi therapy.

Purpose: To analyze the effect of lack of standardization on the reliability of current measurement techniques for glenoid bone loss in clinical practice., Methods: Ten consecutive patients with anterior glenoid bone loss due to recurrent anterior shoulder instability and available computed tomographic (CT) scans of the affected shoulder were included in this study. One hundred seventy 3-dimensional en-face view images of the 10 glenoids with up to 20° degrees of tilt in the anterior, posterior, superior, and inferior direction were rendered. Three independent observers first identified the en-face view images and subsequently performed measurements of the defect surface and diameter as well as the glenoid surface and diameter on all 170 images. Measurements were completed based on the conventional best-fit circle technique using the edge of the visible glenoid bone as reference and additionally based on the so-called spoon technique, which places the best-fit circle on the edge of the visible glenoid concavity., Results: The overall agreement regarding en-face view image selection between the observers was 30% (K-alpha = 0.10, 95% confidence interval 0.02-0.22). Tilt of the en-face view in any direction resulted in significant alterations of all 4 measurement parameters as well as the relative defect area and diameter (P < .05). The conventional and the spoon techniques rendered significantly different results regarding all 4 measurement parameters as well as the relative defect area (P < .05)., Conclusion: Impreciseness of scapula positioning for creation of an en-face view of the glenoid as well as varying best-fit circle placement significantly alter glenoid defect size measurement results., Clinical Relevance: Because the glenoid defect size plays an important role in the choice of treatment for anterior shoulder instability, measurement techniques need to be as precise as possible., (Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

We describe three cases of severe hyponatraemia in the setting of primary polydipsia that were managed in our centre in 2016. Despite receiving different solute loads, large volume diuresis and rapid correction of serum sodium occurred in all cases. Given the potentially catastrophic consequence of osmotic demyelination, we highlight the judicious use of desmopressin and hypotonic fluid infusion to mitigate sodium overcorrection in this setting., (© 2017 Royal Australasian College of Physicians.)

FASTK family proteins have been identified as regulators of mitochondrial RNA homeostasis linked to mitochondrial diseases, but much remains unknown about these proteins. We show that CRISPR-mediated disruption of FASTKD1 increases ND3 mRNA level, while disruption of FASTKD4 reduces the level of ND3 and of other mature mRNAs including ND5 and CYB, and causes accumulation of ND5-CYB precursor RNA. Disrupting both FASTKD1 and FASTKD4 in the same cell results in decreased ND3 mRNA similar to the effect of depleting FASTKD4 alone, indicating that FASTKD4 loss is epistatic. Interestingly, very low levels of FASTKD4 are sufficient to prevent ND3 loss and ND5-CYB precursor accumulation, suggesting that FASTKD4 may act catalytically. Furthermore, structural modeling predicts that each RAP domain of FASTK proteins contains a nuclease fold with a conserved aspartate residue at the putative active site. Accordingly, mutation of this residue in FASTKD4 abolishes its function. Experiments with FASTK chimeras indicate that the RAP domain is essential for the function of the FASTK proteins, while the region upstream determines RNA targeting and protein localization. In conclusion, this paper identifies new aspects of FASTK protein biology and suggests that the RAP domain function depends on an intrinsic nucleolytic activity., (© The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.)

The Fas-activated serine/threonine kinase (FASTK) family of proteins has recently emerged as a central regulator of mitochondrial gene expression through the function of an unusual RNA-binding domain named RAP (for RNA-binding domain abundant in Apicomplexans), shared by all six members of the family. Here we describe the role of one of the less characterized members, FASTKD3, in mitochondrial RNA metabolism. First, we show that, in contrast to FASTK, FASTKD2, and FASTKD5, FASTKD3 does not localize in mitochondrial RNA granules, which are sites of processing and maturation of mtRNAs and ribosome biogenesis. Second, we generated FASTKD3 homozygous knock-out cell lines by homologous recombination and observed that the absence of FASTKD3 resulted in increased steady-state levels and half-lives of a subset of mature mitochondrial mRNAs: ND2, ND3, CYTB, COX2, and ATP8/6. No aberrant processing of RNA precursors was observed. Rescue experiments demonstrated that RAP domain is required for FASTKD3 function in mRNA stability. Besides, we describe that FASTKD3 is required for efficient COX1 mRNA translation without altering mRNA levels, which results in a decrease in the steady-state levels of COX1 protein. This finding is associated with reduced mitochondrial complex IV assembly and activity. Our observations suggest that the function of this family of proteins goes beyond RNA processing and ribosome assembly and includes RNA stability and translation regulation within mitochondria., (© 2016 by The American Society for Biochemistry and Molecular Biology, Inc.)

Introduction: Arthroscopic glenoid reconstruction using a tricortical iliac crest bone graft is performed to anatomically reconstruct the glenoid and reestablish glenohumeral stability in patients with chronic anteroinferior shoulder instability and substantial osseous defects 1-3 ., Step 1 Patient Positioning: Place the patient in the lateral decubitus position and prepare the arm and ipsilateral iliac crest., Step 2 Diagnostic Arthroscopy and Portal Placement: Perform a diagnostic arthroscopy via the posterior portal and establish an anteroinferior, an anterosuperior, and a deep anteroinferior portal., Step 3 Capsulolabral Complex Release and Scapular Neck Preparation: Depending on the pathology and morphology of the defect, release the capsulolabral complex from the scapular neck and prepare the glenoid rim and scapular neck with a motorized burr to ensure adequate osseous healing., Step 4 Harvesting and Preparation of the Iliac Crest Bone Block: Harvest an autologous tricortical iliac crest bone block from the ipsilateral side and contour it appropriately for an anatomic reconstruction of the glenoid., Step 5 Graft Insertion and Positioning: Enlarge the passage for the graft through the rotator interval, insert the bone block, and position it anatomically at the scapular neck., Step 6 Graft Fixation: With the aid of a drill sleeve, temporarily stabilize the graft using Kirschner wires and then definitively attach it to the scapular neck using 2 Bio-Compression screws., Step 7 Capsulolabral Repair: Reattach the capsulolabral complex to the original glenoid, inferior and superior to the bone block, using 2 knotless suture anchors to complete the anatomic reconstruction of the glenoid., Step 8 Rehabilitation and Postoperative Treatment: Immobilize the arm for 6 weeks postoperatively and limit flexion and external rotation during this time period., Results: Fifteen patients with a mean age of 31.4 years (range, 17 to 49 years) with anteroinferior glenohumeral instability and substantial glenoid defects underwent arthroscopic iliac crest bone-grafting and were prospectively evaluated for an average period of 20.6 months (range, 12 to 65 months) 12 .

In mitochondria, DNA replication, gene expression, and RNA degradation machineries coexist within a common nondelimited space, raising the question of how functional compartmentalization of gene expression is achieved. Here, we discuss the recently characterized "mitochondrial RNA granules," mitochondrial subdomains with an emerging role in the regulation of gene expression., (© 2016 Jourdain et al.)

Proliferating cell nuclear antigen (PCNA) plays critical roles in many aspects of DNA replication and replication-associated processes, including translesion synthesis, error-free damage bypass, break-induced replication, mismatch repair, and chromatin assembly. Since its discovery, our view of PCNA has evolved from a replication accessory factor to the hub protein in a large protein-protein interaction network that organizes and orchestrates many of the key events at the replication fork. We begin this review article with an overview of the structure and function of PCNA. We discuss the ways its many interacting partners bind and how these interactions are regulated by posttranslational modifications such as ubiquitylation and sumoylation. We then explore the many roles of PCNA in normal DNA replication and in replication-coupled DNA damage tolerance and repair processes. We conclude by considering how PCNA can interact physically with so many binding partners to carry out its numerous roles. We propose that there is a large, dynamic network of linked PCNA molecules at and around the replication fork. This network would serve to increase the local concentration of all the proteins necessary for DNA replication and replication-associated processes and to regulate their various activities., (© 2016 Elsevier Inc. All rights reserved.)