Determinants that enable disordered protein assembly into discrete condensed phases.

Cells harbour numerous mesoscale membraneless compartments that house specific biochemical processes and perform distinct cellular functions. These protein- and RNA-rich bodies are thought to form through multivalent interactions among proteins and nucleic acids, resulting in demixing via liquid-liquid phase separation. Proteins harbouring intrinsically disordered regions (IDRs) predominate in membraneless organelles. However, it is not known whether IDR sequence alone can dictate the formation of distinct condensed phases. We identified a pair of IDRs capable of forming spatially distinct condensates when expressed in cells. When reconstituted in vitro, these model proteins do not co-partition, suggesting condensation specificity is encoded directly in the polypeptide sequences. Through computational modelling and mutagenesis, we identified the amino acids and chain properties governing homotypic and heterotypic interactions that direct selective condensation. These results form the basis of physicochemical principles that may direct subcellular organization of IDRs into specific condensates and reveal an IDR code that can guide construction of orthogonal membraneless compartments.

SQSTM1/P62 promotes lysophagy via formation of liquid-like condensates maintained by HSP27.

ABBREVIATIONS: SQSTM1/p62: Sequestosome-1; HSP27: Heat shock protein 27; LLPS: liquid-liquid phase separation; iPSC: induced pluripotent stem cell; PB1: Phox and Bem1p; FRAP: fluorescence recovery after photo-bleaching; ATG: autophagy-related; ALS: amyotrophic lateral sclerosis.

Determinants of Disordered Protein Co-Assembly Into Discrete Condensed Phases.

Cells harbor numerous mesoscale membraneless compartments that house specific biochemical processes and perform distinct cellular functions. These protein and RNA-rich bodies are thought to form through multivalent interactions among proteins and nucleic acids resulting in demixing via liquid-liquid phase separation (LLPS). Proteins harboring intrinsically disordered regions (IDRs) predominate in membraneless organelles. However, it is not known whether IDR sequence alone can dictate the formation of distinct condensed phases. We identified a pair of IDRs capable of forming spatially distinct condensates when expressed in cells. When reconstituted in vitro, these model proteins do not co-partition, suggesting condensation specificity is encoded directly in the polypeptide sequences. Through computational modeling and mutagenesis, we identified the amino acids and chain properties governing homotypic and heterotypic interactions that direct selective condensation. These results form the basis of physicochemical principles that may direct subcellular organization of IDRs into specific condensates and reveal an IDR code that can guide construction of orthogonal membraneless compartments.

The selective autophagy adaptor p62/SQSTM1 forms phase condensates regulated by HSP27 that facilitate the clearance of damaged lysosomes via lysophagy.

In response to lysosomal damage, cells engage several quality-control mechanisms, including the selective isolation and degradation of damaged lysosomes by lysophagy. Here, we report that the selective autophagy adaptor SQSTM1/p62 is recruited to damaged lysosomes in both HeLa cells and neurons and is required for lysophagic flux. The Phox and Bem1p (PB1) domain of p62 mediates oligomerization and is specifically required for lysophagy. Consistent with this observation, we find that p62 forms condensates on damaged lysosomes. These condensates are precisely tuned by the small heat shock protein HSP27, which is phosphorylated in response to lysosomal injury and maintains the liquidity of p62 condensates, facilitating autophagosome formation. Mutations in p62 have been identified in patients with amyotrophic lateral sclerosis (ALS); ALS-associated mutations in p62 impair lysophagy, suggesting that deficits in this pathway may contribute to neurodegeneration. Thus, p62 condensates regulated by HSP27 promote lysophagy by forming platforms for autophagosome biogenesis at damaged lysosomes.

Establishment and initial implementation of the Australasian Pelvic Floor Procedure Registry.

INTRODUCTION AND HYPOTHESIS: Stress urinary incontinence (SUI) and pelvic organ prolapse (POP) are common pelvic floor disorders (PFDs). Owing to significant adverse events associated with mesh-related pelvic floor procedures (PFPs) in a proportion of the surgically treated population, and deficits in collection and reporting of these events, the Australian Government identified an urgent need for a tracking mechanism to improve safety and quality of care. The Australasian Pelvic Floor Procedure Registry (APFPR) was recently established following the 2018 Senate Committee Inquiry with the aim of tracking outcomes of PFP involving the use of devices and/or prostheses, with the objective of improving the health outcomes of women who undergo these procedures. This paper will describe the APFPR's aims, development, implementation and possible challenges on the way to its establishment. METHODS: The APFPR has been developed and implemented in accordance with the national operating principles of clinical quality registries (CQRs). The minimum datasets (MDS) for the registry's database have been developed using a modified Delphi process, and data are primarily being collected from participating surgeons. Patient recruitment is based on an opt-out approach or a waiver of consent. Patient-reported outcome measures (PROMs) providing additional health and outcome information will be obtained from participating women to support safety monitoring of mesh-related adverse events. RESULTS: Currently in the Australasian Pelvic Floor Procedure Registry (APFPR) there are 32 sites from various jurisdictions across Australia, that have obtained relevant ethics and governance approvals to start patient recruitment and data collection as of January 2023. Additionally, there are two sites that are awaiting governance review and five sites that are having documentation compiled for submission. Seventeen sites have commenced patient registration and have entered data into the database. Thus far, we have 308 patients registered in the APFPR database. The registry also published its first status report and a consumer-friendly public report in 2022. CONCLUSIONS: The registry will act as a systematic tracking mechanism by collecting outcomes on PFP, especially those involving devices and/or prostheses to improve safety and quality of care.

The first crystal structures of hybrid and parallel four-tetrad intramolecular G-quadruplexes.

G-quadruplexes (GQs) are non-canonical DNA structures composed of stacks of stabilized G-tetrads. GQs play an important role in a variety of biological processes and may form at telomeres and oncogene promoters among other genomic locations. Here, we investigate nine variants of telomeric DNA from Tetrahymena thermophila with the repeat (TTGGGG)n. Biophysical data indicate that the sequences fold into stable four-tetrad GQs which adopt multiple conformations according to native PAGE. Excitingly, we solved the crystal structure of two variants, TET25 and TET26. The two variants differ by the presence of a 3'-T yet adopt different GQ conformations. TET25 forms a hybrid [3 + 1] GQ and exhibits a rare 5'-top snapback feature. Consequently, TET25 contains four loops: three lateral (TT, TT, and GTT) and one propeller (TT). TET26 folds into a parallel GQ with three TT propeller loops. To the best of our knowledge, TET25 and TET26 are the first reported hybrid and parallel four-tetrad unimolecular GQ structures. The results presented here expand the repertoire of available GQ structures and provide insight into the intricacy and plasticity of the 3D architecture adopted by telomeric repeats from T. thermophila and GQs in general.

The utility of paired upper and lower respiratory tract sampling for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing in patients with artificial airways.

Early in the coronavirus disease 2019 (COVID-19) pandemic, the CDC recommended collection of a lower respiratory tract (LRT) specimen for severe acute respiratory coronavirus virus 2 (SARS-CoV-2) testing in addition to the routinely recommended upper respiratory tract (URT) testing in mechanically ventilated patients. Significant operational challenges were noted at our institution using this approach. In this report, we describe our experience with routine collection of paired URT and LRT sample testing. Our results revealed a high concordance between the 2 sources, and that all children tested for SARS-CoV-2 were appropriately diagnosed with URT testing alone. There was no added benefit to LRT testing. Based on these findings, our institutional approach was therefore adjusted to sample the URT alone for most patients, with LRT sampling reserved for patients with ongoing clinical suspicion for SARS-CoV-2 after a negative URT test.

"I'm Getting Older Too": Challenges and Benefits Experienced by Very Old Parents and Their Children.

Very old parents and their "old" children are a growing group in industrialized countries worldwide. However, virtually nothing is known about the nature and implications of this relationship constellation. To fill this gap, this study explored the challenges and rewards of the very old parent-child relationship. In-depth interviews were conducted with 114 parent-child dyads (parent age ≥90; child age ≥65). While both challenges and rewards were present, the balance of challenges and rewards was notably less favorable for children with more challenges experienced overall. Challenges reported by children were often characterized by references to children's own advanced age and health problems, and the prolonged caregiving involvement due to their parents' longevity. Health care professionals, policymakers, and families should be made aware of this increasingly common phenomenon, and specific services and policies will be needed to adequately support very old adults and their families.

Mortality of 196,826 Men and Women Working in U.S.-Based Petrochemical and Refinery Operations: Update 1979 to 2010.

OBJECTIVE: To describe mortality trends of men and women working in various petrochemical and refinery operations of a U.S.-based company. METHODS: The cohort consists of full-time employees with at least 1 day of service during 1979 through 2010. Standardized mortality ratios (SMRs) and 95% confidence intervals (CIs) were calculated for 111 possible causes of death studied. RESULTS: SMRs for malignant mesothelioma and asbestosis were highest for the 1940s decade of hire. Increased SMRs were observed for malignant melanoma and motor neuron disease with no obvious work patterns. Decreasing mortality patterns were observed for aplastic anemia and acute nonlymphocytic leukemia. CONCLUSIONS: Mortality surveillance of this large established cohort aids in assessing the chronic health status of the workforce. Identifying methods for incorporating job-exposure matrices and nonoccupational risk factors could further enhance interpretations for some findings such as motor neuron disease.

Cognitive Functioning, Gender, and Marital Quality Among Older Married Couples: A Dyadic Approach.

This study examines associations of older husbands' and wives' cognitive functioning with both partners' marital quality. Generalized structural equation modeling analyzed data from 1,432 opposite-sex couples drawn from the 2016 wave of the Health and Retirement Study. Findings revealed that wives' poorer cognitive functioning was associated with wives reporting greater closeness and enjoyment of time with a spouse, whereas husbands' poorer cognitive functioning was associated with wives reporting greater marital strain, lower marital support, lower closeness, and less enjoyment of time with a spouse. This suggests that cognitive functioning has dyadic consequences for marital quality, which are highly gendered.

Improvement in Uncontrolled Eating Behavior after Laparoscopic Sleeve Gastrectomy Is Associated with Alterations in the Brain-Gut-Microbiome Axis in Obese Women.

BACKGROUND: Bariatric surgery is proven to change eating behavior and cause sustained weight loss, yet the exact mechanisms underlying these changes are not clearly understood. We explore this in a novel way by examining how bariatric surgery affects the brain-gut-microbiome (BGM) axis. METHODS: Patient demographics, serum, stool, eating behavior questionnaires, and brain magnetic resonance imaging (MRI) were collected before and 6 months after laparoscopic sleeve gastrectomy (LSG). Differences in eating behavior and brain morphology and resting-state functional connectivity in core reward regions were correlated with serum metabolite and 16S microbiome data. RESULTS: LSG resulted in significant weight loss and improvement in maladaptive eating behaviors as measured by the Yale Food Addiction Scale (YFAS). Brain imaging showed a significant increase in brain volume of the putamen (p.adj < 0.05) and amygdala (p.adj < 0.05) after surgery. Resting-state connectivity between the precuneus and the putamen was significantly reduced after LSG (p.adj = 0.046). This change was associated with YFAS symptom count. Bacteroides, Ruminococcus, and Holdemanella were associated with reduced connectivity between these areas. Metabolomic profiles showed a positive correlation between this brain connection and a phosphatidylcholine metabolite. CONCLUSION: Bariatric surgery modulates brain networks that affect eating behavior, potentially through effects on the gut microbiota and its metabolites.

Buffer or Blade: Perceived relationship closeness in couples navigating Alzheimer's.

Given the paucity of support from the welfare state, the lion's share of care for American seniors with memory loss is shouldered by their spouses who tend to be older and sometimes are frail themselves. Previous research has bifurcated attention to either accounts from diagnosed individuals or carers rather than understanding the experience within a socio-relational context of sometimes half-century long relationships. The present study was a qualitative investigation of 11 community-dwelling dyads (N = 22) living in the Greater Boston Area to understand how married heterosexual couples experience Alzheimer's. They were predominately white, highly educated individuals with mild to moderate AD and their spouses. Grounded theory methodologies were used to collect, code, and analyze all narrative study data. The data from these spousal dyads reveal that most couples approached AD as a joint challenge and were committed to maintaining their prior roles and lives for as long as possible, including shared outlooks, approaches, and activities. By showing how some couples navigate AD together rather than separately, these data provide an important counter narrative to the burden-based framing of AD in our social imagination. Regardless of perceptions of relationship closeness, all dyads employed strategies to live life positively with Alzheimer's. Despite being a highly privileged sample, or an "ideal type," these data reveal the importance of studying AD as a coupled or family event; that is, a social and relational matter, rather than simply an individual medical problem. They also highlight the importance of relationship-centered care in meeting families "where they are" in terms of existing social roles. Universalizing all AD experiences leads to an over-reliance on reductionist tropes such as "stress" and "burden" and exacerbates the very real threat to social disenfranchisement.

Perceptions of couplehood among community-dwelling spousal caregivers.

Objective: Spousal caregiving is increasingly common, and it is a role that can alter the nature of marriage in later life. Some may find spousal caregiving to be distressing, while others may have more positive experiences. Spousal caregiving, in particular, may be difficult due to caregiver burden as well as a loss of couplehood within the relationship. The current study used grounded theory methods to better understand the experience of and changes in couplehood among spousal caregivers.Method: Thirteen spousal caregivers completed semi-structured interviews. Spousal caregivers ranged in age from 53 to 85 (mean age = 66.00, SD = 9.04).Results: Qualitative analysis revealed four major themes upon evaluation of the interviews (couplehood, positive mindset, later life roles and transitions, and looking towards the future).Conclusion: These themes exemplified the complex interplay of couplehood and caregiving as well as the range of perceptions of couplehood. Results showed that while some caregivers struggle to find meaning and happiness within their caregiver role, and others said the illness/impairment bonded them together. Caregivers who reported a low sense couplehood discussed feeling trapped in their relationship, sad, and isolated. For some caregivers, a strong sense of couplehood may have helped them reframe the experience as an opportunity to be a role model for others and a reminder that their situation could be worse. Future research should focus on pre-illness couplehood and whether the nature of the impairment (e.g., cognitive, physical) is related to caregiver's couplehood.

ToolBox: Live Imaging of intracellular organelle transport in induced pluripotent stem cell-derived neurons.

Induced pluripotent stem cells (iPSCs) hold promise to revolutionize studies of intracellular transport in live human neurons and to shed new light on the role of dysfunctional transport in neurodegenerative disorders. Here, we describe an approach for live imaging of axonal and dendritic transport in iPSC-derived cortical neurons. We use transfection and transient expression of genetically-encoded fluorescent markers to characterize the motility of Rab-positive vesicles, including early, late and recycling endosomes, as well as autophagosomes and mitochondria in iPSC-derived neurons. Comparing transport parameters of these organelles with data from primary rat hippocampal neurons, we uncover remarkable similarities. In addition, we generated lysosomal-associated membrane protein 1 (LAMP1)-enhanced green fluorescent protein (EGFP) knock-in iPSCs and show that knock-in neurons can be used to study the transport of endogenously labeled vesicles, as a parallel approach to the transient overexpression of fluorescently labeled organelle markers.

Food Income and the Evolution of Forager Mobility.

Forager mobility tends to be high, although ethnographic studies indicate ecological factors such as resource abundance and reliability, population density and effective temperature influence the cost-to-benefit assessment of movement decisions. We investigate the evolution of mobility using an agent-based and spatially explicit cultural evolutionary model that considers the feedback between foragers and their environment. We introduce Outcomes Clustering, an approach to categorizing simulated system states arising from complex stochastic processes shaped by multiple interacting parameters. We find that decreased mobility evolves under conditions of high resource replenishment and low resource depletion, with a concomitant trend of increased population density and, counter-intuitively, decreased food incomes. Conversely, increased mobility co-occurs with lower population densities and higher food incomes. We replicate the well-known relationships between mobility, population density, and resource quality, while predicting reduced food income, and consequently the reduction in health status observed in early sedentary populations without the need to invoke factors such as reduced diet quality or increased pathogen loads.

Finite element investigation into the use of carbon fibre reinforced PEEK laminated composites for distal radius fracture fixation implants.

Carbon fibre reinforced PEEK (CF/PEEK) laminates provide mechanical advantages over homogenous metal osteo-synthesis implants, e.g. radiolucency, fatigue strength and strength to weight ratio. Implants can be designed with custom anisotropic material properties, thus enabling the engineer to tailor the overall stiffness of the implant to the specific loading conditions it will experience in vivo. In the current study a multi-scale computational investigation of idealised distal radius fracture fixation plate (DRP) is conducted. Physiological loading conditions are applied to macro-scale finite element models of DRPs. The mechanical response is compared for several CF/PEEK laminate layups to examine the effect of ply layup design. The importance of ply orientation in laminated DRPs is highlighted. A high number of 0° plies near the outer surfaces results in a greater bending strength while the addition of 45° plies increases the torsional strength of the laminates. Intra-laminar transverse tensile failure is predicted as the primary mode of failure. A micro-mechanical analysis of the CF/PEEK microstructure uncovers the precise mechanism under-lying intra-laminar transverse tensile crack to be debonding of the PEEK matrix from carbon fibres. Plastic strains in the matrix material are not sufficiently high to result in ductile failure of the matrix. The findings of this study demonstrate the significant challenge in the design and optimisation of fibre reinforced laminated composites for orthopaedic applications, highlighting the importance of multi-scale modelling for identification of failure mechanisms.

Simulation for Clinical Preparedness in Pediatric Emergencies: A Pilot Study.

Positive outcomes for pediatric in-hospital cardiopulmonary arrest remain low with little change in mortality rates. Infrequently used clinical knowledge and skills decline quickly, contributing to poor quality of resuscitation. The aim of this pilot study exploring the outcomes of repeated pediatric mock code simulations with structured debriefing demonstrated statistically significant differences in participants' knowledge of pediatric emergencies, with no significant decline in resuscitation skills. This provides an evidence-based approach for professional development educators working with nurses on pediatric emergencies.

Crop Growers' Adaptive Capacity to Climate Change: A Situated Study of Agriculture in Arizona's Verde Valley.

Climate change will pose unprecedented challenges for agricultural producers globally, requiring the ability to adapt to new and unpredictable conditions. This study explores the adaptive capacity of crop growers in the Verde Valley, Arizona (US). Rather than examining pre-determined indicators of adaptive capacity, this study adopts a situated framework that examines material conditions, perceptions, and the larger social context. Interviewers used past experiences and future scenarios to allow factors that enhance or constrain adaptive capacity to emerge from the interviews. Findings reveal adaptation is site specific but general measures can be taken to enhance adaptive capacity. Encouraging diversity in crops and water sources, the use of drought and heat tolerant crops, and the use of water conservation practices will likely increase growers' adaptive capacity. In contrast, lack of support from organizations and government programs, lack of diverse crops and sources of water, lack of awareness about climate change, and growers' confidence in their ability to always adapt impairs adaptive capacity. Verde Valley growers will need increased support from local and national organizations to adapt to projected changes. The situated framework applied in this study reveals important insights and could be used to explore adaptive capacity in other agricultural regions.

Systematic Review and Meta-Analysis of Selected Cancers in Petroleum Refinery Workers.

OBJECTIVE: We studied the risk of 11 cancers of a priori interest in petroleum refinery workers. METHODS: Iterative searches identified 36 studies for the 11 cancer sites. Statistical heterogeneity and publication bias were assessed to enhance interpretation of meta-relative risks. RESULTS: Statistical heterogeneity was marked for mesothelioma, but was largely due to study quality. Higher quality studies showed a meta-relative risk (RR) of 3.22, (95% prediction interval 1.45 to 7.23). Melanoma (meta-RR = 1.23) and acute lymphoid leukemia (meta-RR = 1.51), showed results consistent with higher risk, but both were driven by one or two studies. Eight other cancer outcomes showed summary meta-RR's consistent with unity. CONCLUSIONS: Most cancer outcomes are consistent with background risk in refinery workers. This work has clarified an excess mesothelioma risk, conditional on study quality stratification. Continued surveillance is warranted for melanoma and ALL.

Multi-axial damage and failure of medical grade carbon fibre reinforced PEEK laminates: Experimental testing and computational modelling.

Orthopaedic devices using unidirectional carbon fibre reinforced poly-ether-ether-ketone (PEEK) laminates potentially offer several benefits over metallic implants including: anisotropic material properties; radiolucency and strength to weight ratio. However, despite FDA clearance of PEEK-OPTIMA™ Ultra-Reinforced, no investigation of the mechanical properties or failure mechanisms of a medical grade unidirectional laminate material has been published to date, thus hindering the development of first-generation laminated orthopaedic devices. This study presents the first investigation of the mechanical behaviour and failure mechanisms of PEEK-OPTIMA™ Ultra-Reinforced. The following multi-axial suite of experimental tests are presented: 0° and 90° tension and compression, in-plane shear, mode I and mode II fracture toughness, compression of ±45° laminates and flexure of 0°, 90° and ±45° laminates. Three damage mechanisms are uncovered: (1) inter-laminar delamination, (2) intra-laminar cracking and (3) anisotropic plasticity. A computational damage and failure model that incorporates all three damage mechanisms is developed. The model accurately predicts the complex multi-mode failure mechanisms observed experimentally. The ability of a model to predict diverse damage mechanisms under multiple loading directions conditions is critical for the safe design of fibre reinforced laminated orthopaedic devices subjected to complex physiological loading conditions.