Probing binding and occlusion of substrate in the human creatine transporter-1 by computation and mutagenesis.

In chordates, energy buffering is achieved in part through phosphocreatine, which requires cellular uptake of creatine by the membrane-embedded creatine transporter (CRT1/SLC6A8). Mutations in human slc6a8 lead to creatine transporter deficiency syndrome, for which there is only limited treatment. Here, we used a combined homology modeling, molecular dynamics, and experimental approach to generate a structural model of CRT1. Our observations support the following conclusions: contrary to previous proposals, C144, a key residue in the substrate binding site, is not present in a charged state. Similarly, the side chain D458 must be present in a protonated form to maintain the structural integrity of CRT1. Finally, we identified that the interaction chain Y148-creatine-Na+ is essential to the process of occlusion, which occurs via a "hold-and-pull" mechanism. The model should be useful to study the impact of disease-associated point mutations on the folding of CRT1 and identify approaches which correct folding-deficient mutants.

A zebrafish reporter line reveals immune and neuronal expression of endogenous retrovirus.

Endogenous retroviruses (ERVs) are fossils left in our genome from retrovirus infections of the past. Their sequences are part of every vertebrate genome and their random integrations are thought to have contributed to evolution. Although ERVs are mainly silenced by the host genome, they have been found to be activated in multiple disease states, such as auto-inflammatory disorders and neurological diseases. However, the numerous copies in mammalian genomes and the lack of tools to study them make defining their role in health and diseases challenging. In this study, we identified eight copies of the zebrafish endogenous retrovirus zferv. We created and characterised the first in vivo ERV reporter line in any species. Using a combination of live imaging, flow cytometry and single-cell RNA sequencing, we mapped zferv expression to early T cells and neurons. Thus, this new tool identified tissues expressing ERV in zebrafish, highlighting a potential role of ERV during brain development and strengthening the hypothesis that ERV play a role in immunity and neurological diseases. This transgenic line is therefore a suitable tool to study the function of ERV in health and diseases.

Microstructure and Thickness Effects on Impact Behavior and Separation Formation in X70 Pipeline Steel.

In an effort to optimize the transportation of oil and gas, the pipeline industry is developing large-diameter, thick-walled pipelines that can withstand low temperatures and high pressures. In this study, three X70 steel plates of similar chemistry, ranging in thickness from 13.5 mm to 22 mm, were subjected to drop-weight tear and Charpy V-notch tests to determine the effects of plate thickness and microstructure on the formation of separations and impact behavior. Constraint induced by specimen thickness appears to dictate the location of separations, the three microstructures exhibited different separation behaviors, and microstructural banding was not found to promote separation formation. Separations were most frequent when the primary fracture plane was parallel to the rolling direction. This study also found that standardized empirical relationships between Charpy V-notch and drop-weight tear tests do not estimate to the advanced high-strength and -toughness steels investigated.

Prevalence and correlates of physical activity across kidney disease stages: an observational multicentre study.

BACKGROUND: People with chronic kidney disease (CKD) report high levels of physical inactivity, a major modifiable risk factor for morbidity and mortality. Understanding the biological, psychosocial and demographic causes of physical activity behaviour is essential for the development and improvement of potential health interventions and promotional initiatives. This study investigated the prevalence of physical inactivity and determined individual correlates of this behaviour in a large sample of patients across the spectrum of kidney disease. METHODS: A total of 5656 people across all stages of CKD (1-2, 3, 4-5, haemodialysis, peritoneal dialysis and renal transplant recipients) were recruited from 17 sites in England from July 2012 to October 2018. Physical activity was evaluated using the General Practice Physical Activity Questionnaire. Self-reported cardiorespiratory fitness, self-efficacy and stage of change were also assessed. Binominal generalized linear mutually adjusted models were conducted to explore the associations between physical activity and correlate variables. This cross-sectional observational multi-centre study was registered retrospectively as ISRCTN87066351 (October 2015). RESULTS: The prevalence of physical activity (6-34%) was low and worsened with disease progression. Being older, female and having a greater number of comorbidities were associated with greater odds of being physically inactive. Higher haemoglobin, cardiorespiratory fitness and self-efficacy levels were associated with increased odds of being active. Neither ethnicity nor smoking history had any effect on physical activity. CONCLUSIONS: Levels of physical inactivity are high across all stages of CKD. The identification of stage-specific correlates of physical activity may help to prioritize factors in target groups of kidney patients and improve the development and improvement of public health interventions.

Promoting integrated care in prostate cancer through online prostate cancer-specific holistic needs assessment: a feasibility study in primary care.

PURPOSE: This study assessed the feasibility of implementing a novel model of integrated prostate cancer care involving an online prostate cancer-specific holistic needs assessment (sHNA) and shared digital communication between patients and their healthcare professionals (HCPs). The sHNA produces a semi-automated care plan that is finalised in consultation between the patient and their practice nurse. METHODS: Men living with and beyond prostate cancer were invited to participate in a 9-month non-randomised cluster controlled feasibility study. The intervention group was asked to complete the sHNA on three occasions. Data were collected using Patient Reported Outcome Measures (PROMs) at baseline, 10 and 24 weeks, and 9 months. Outcomes included recruitment, retention, acceptability, and engagement with the sHNA and PROMs. RESULTS: Fourteen general practices (8 intervention and 6 control), and 41 men (29 intervention and 12 control) participated. Initial patient engagement with the sHNA was high, with all but one receiving practice nurse-led follow-up and an individualised care plan. The sHNA proved useful in identifying 'red flag' symptoms, and helping practice nurses decide when to seek further medical care for the patients. There was a high level of acceptability for patients and HCPs. However, integration of care did not occur as intended because of problems linking hospital and general practice IT systems. CONCLUSION: While the study demonstrated the feasibility of implementing the sHNA, it did not meet the a priori progression criteria; as such, undertaking a definitive randomised controlled trial is not appropriate until the identified methodological and technical issues have been addressed.

"My gut feeling is we could do more..." a qualitative study exploring staff and patient perspectives before and after the implementation of an online prostate cancer-specific holistic needs assessment.

BACKGROUND: Men surviving prostate cancer report a wide range of unmet needs. Holistic needs assessments (HNA) are designed to capture these, but are traditionally paper-based, generic, and only carried out in secondary care despite national initiatives advocating a "shared care" approach. We developed an online prostate cancer-specific HNA (sHNA) built into existing IT healthcare infrastructure to provide a platform for service integration. Barriers and facilitators to implementation and use of the sHNA were explored from both the patients and healthcare professionals (HCPs) perspectives. METHODS: This qualitative study consisted of two phases. Phase 1 used semi-structured interviews to explore HCPs (n = 8) and patients (n = 10) perceptions of the sHNA, prior to implementation. Findings were used to develop an implementation strategy. Phase 2 used semi-structured interviews to explore HCPs (n = 4) and patients (n = 7) experienced barriers and motivators to using the sHNA, 9 to 12 months after implementation. Interviews were audio-recorded, transcribed verbatim and thematically analysed. Themes were mapped to the Theoretical Domains Framework. RESULTS: HCPs and patients anticipated many benefits from using the sHNA. Barriers to implementation included: confidence to work in depth with prostate cancer patients, organisational and cultural change, and patient factors. Our implementation strategy addressed these barriers by the provision of disease specific training delivered in part by a clinical nurse specialist; and a peer-led IT supporter. Following implementation HCPs and patients perceived the sHNA as beneficial to their practice and care, respectively. However, some patients experienced barriers in using the sHNA related predominately to symptom perception and time since treatment. HCPs suggested minor software refinements. CONCLUSIONS: This work supports the importance of identifying barriers and motivators to implementation, and using targeted action via the development of an implementation strategy to address these. Whilst this process should be on-going, undertaking this work at an early stage will help to optimise the implementation of the sHNA for future trials.