Copper(II) Affects the Biochemical Behavior of Proinsulin C-peptide by Forming Ternary Complexes with Serum Albumin.

Peptide hormones are essential signaling molecules with therapeutic importance. Identifying regulatory factors that drive their activity gives important insight into their mode of action and clinical development. In this work, we demonstrate the combined impact of Cu(II) and the serum protein albumin on the activity of C-peptide, a 31-mer peptide derived from the same prohormone as insulin. C-peptide exhibits beneficial effects, particularly in diabetic patients, but its clinical use has been hampered by a lack of mechanistic understanding. We show that Cu(II) mediates the formation of ternary complexes between albumin and C-peptide and that the resulting species depend on the order of addition. These ternary complexes notably alter peptide activity, showing differences from the peptide or Cu(II)/peptide complexes alone in redox protection as well as in cellular internalization of the peptide. In standard clinical immunoassays for measuring C-peptide levels, the complexes inflate the quantitation of the peptide, suggesting that such adducts may affect biomarker quantitation. Altogether, our work points to the potential relevance of Cu(II)-linked C-peptide/albumin complexes in the peptide's mechanism of action and application as a biomarker.

Efficacy and toxicity of primary re-irradiation for malignant spinal cord compression based on radiobiological modelling: a phase II clinical trial.

BACKGROUND: The efficacy and safety of primary re-irradiation for MSCC are not known. Our aim was to establish the efficacy and safety of biologically effective dose-based re-irradiation. METHODS: Patients presenting with MSCC at a previously irradiated spine segment, and not proceeding with surgical decompression, were eligible. A 3 Gray per fraction experimental schedule (minimum 18 Gy/6 fractions, maximum 30 Gy/10 fractions) was used, delivering a maximum cumulative spinal dose of 100 Gy2 if the interval since the last radiotherapy was within 6 months, or 130 Gy2 if longer. The primary outcome was a change in mobility from week 1 to week 5 post-treatment, as assessed by the Tomita score. The RTOG SOMA score was used to screen for spinal toxicity, and an MRI performed to assess for radiation-induced myelopathy (RIM). RESULTS: Twenty-two patients were enroled, of whom eleven were evaluable for the primary outcome. Nine of eleven (81.8%) had stable or improved Tomita scores at 5 weeks. One of eight (12.5%) evaluable for late toxicity developed RIM. CONCLUSIONS: Re-irradiation is an efficacious treatment for MSCC. There is a risk of RIM with a cumulative dose of 120 Gy2. CLINICAL TRIAL REGISTRATION: Cancer Trials Ireland (ICORG 07-11); NCT00974168.

Evaluation of real-world outcomes associated with use of a prescription digital therapeutic to treat substance use disorders.

BACKGROUND AND OBJECTIVES: Digital therapeutics can expand the reach and fidelity of behavioral treatment for substance use disorders (SUDs). This analysis evaluated real-world engagement and clinical outcomes in patients diagnosed with SUD who were prescribed reSET®, an FDA-authorized prescription digital therapeutic (PDT). METHODS: Patients were prescribed a 12-week PDT comprising 61 therapy lessons (31 "core" and 30 "keep learning" lessons) and contingency management rewards (positive reinforcement message or monetary gift cards) based on lesson completion and negative urine drug screens. Engagement (defined as any activity in the PDT), retention (any activity in Weeks 9-12), and substance use data were collected automatically by the PDT and analyzed descriptively. Associations between early lesson completion and end-of-treatment outcomes were assessed. RESULTS: Six hundred and fifty-eight patients filled their prescription. Evaluated were 602 patients who were exposed to therapeutic content by completing at least one lesson (median age 37 years, 33% female, 41% male, 26% unreported sex). Median lessons completed was 33 (out of 61 possible), and 52% of patients completed all core modules. Retention in treatment during the last 4 weeks of treatment was 74%, and 62% were abstinent (missing data considered positive). [Correction added on 13 December 2022, after first online publication: In the preceding sentence, the treatment percentage values were revised from 74.6% to 74%.] DISCUSSION AND CONCLUSIONS: Patients with SUD exhibited robust engagement with a PDT, high rates of retention through 12 weeks, and substantial rates of abstinence at end of treatment when the therapeutic was used in a real-world setting. PDT's hold promise as a new way to access effective SUD treatment. SCIENTIFIC SIGNIFICANCE: This study is the first to report real-world PDT engagement and clinical outcomes data from a large, geographically diverse population of patients with SUDs.

A comparative analysis of non-invasive prenatal testing in Ontario and Quebec: the role of governing style in health technology innovation & adoption.

BACKGROUND: While processes of adoption and the impacts of various health technologies have been extensively studied by health services and policy researchers, the influence of policy makers' governing styles on these processes have been largely neglected. Through a comparative analysis of non-invasive prenatal testing (NIPT) in the Canadian provinces of Ontario and Quebec, this article examines how decisions about this technology were shaped by contrasting political ideologies, resulting in vastly different innovation and adoption strategies and outcomes. METHODS: A comparative qualitative investigation comprising of a document analysis followed by semi-structured interviews with key informants. Interview participants were researchers, clinicians, and private sector medical laboratory employees based in Ontario and Quebec, Canada. Interviews were conducted both in person and virtually- owing partly to the COVID-19 pandemic - to garner perspectives regarding the adoption and innovation processes surrounding non-invasive prenatal testing in both provinces. All interviews were recorded and transcribed verbatim and data were analyzed using thematic analysis. RESULTS: Through an analysis of 21 in-depth interview transcripts and key documents, the research team identified three central themes: 1) health officials in each province demonstrated a unique approach to using the existing scholarly literature on NIPT; 2) each provincial government demonstrated its own preference for service delivery, with Ontario preferring private and Quebec preferring public; and finally, 3) both Ontario and Quebec's strategies to NIPT adoption and innovation was contextualized within each province's unique financial positioning and concerns. These findings illustrate how both Quebec's nationalist focus and use of industrial policy and Ontario's 'New Public Management' style had implications for how this emerging healthcare technology was made available within each province's publicly-financed health system. CONCLUSIONS: Our study reveals how these governments' differing approaches to using data and research, public versus private service delivery, and financial goals and concerns resulted in distinct testing technologies, access, and timelines for NIPT adoption. Our analysis demonstrates the need for health policy researchers, policy makers, and others to move beyond analyses solely considering clinical and health economic evidence to understand the impact of political ideologies and governing styles.

Evidence Clearinghouses as Tools to Advance Health Equity: What We Know from a Systematic Scan.

Evidence clearinghouses evaluate and summarize literature to help decision-makers prioritize and invest in evidence-informed interventions. Clearinghouses and related practice-oriented tools are continuously evolving; however, it is unclear the extent to which these tools assess and summarize evidence describing an intervention's impact on health equity. We conducted a systematic scan to explore how clearinghouses communicated an intervention's equity impact and reviewed their underlying methods and how they defined and operationalized health equity. In 2021, we identified 18 clearinghouses that were US-focused, web-based registries of interventions that assigned an intervention effectiveness rating for improving community health and the social determinants of health. We reviewed each clearinghouse's website and collected publicly available information about their health equity impact review, review methods, and health equity definitions and values. We conducted a comparative analysis among select clearinghouses using qualitative methods. Among the 18 clearinghouses, fewer than half (only seven) summarized an intervention's potential impact on health equity. Overall, those seven clearinghouses defined and operationalized equity differently, and most lacked transparency in their review methods. Clearinghouses used one or more approaches to communicate findings from their review: summarize study findings on differential impact for subpopulations, curate interventions that reduce health disparities, and/or assign a disparity/equity rating to each intervention. Evidence clearinghouses can enhance equity-focused methods and be transparent in their underlying values to better support the uptake and implementation of evidence-informed interventions to advance health equity. However, clearinghouses are unable to do so without underlying equity-focused empirical evidence.

Clinical features and predictive biomarkers for bladder cancer in patients with type 2 diabetes presenting with haematuria.

AIMS: To identify clinical features and protein biomarkers associated with bladder cancer (BC) in individuals with type 2 diabetes mellitus presenting with haematuria. MATERIALS AND METHODS: Data collected from the Haematuria Biomarker (HaBio) study was used in this analysis. A matched sub-cohort of patients with type 2 diabetes and patients without diabetes was created based on age, sex, and BC diagnosis, using approximately a 1:2 fixed ratio. Randox Biochip Array Technology and ELISA were applied for measurement of 66 candidate serum and urine protein biomarkers. Hazard ratios and 95% confidence intervals were estimated by chi-squared and Wilcoxon rank sum test for clinical features and candidate protein biomarkers. Diagnostic protein biomarker models were identified using Lasso-based binominal regression analysis. RESULTS: There was no difference in BC grade, stage, and severity between individuals with type 2 diabetes and matched controls. Incidence of chronic kidney disease (CKD) was significantly higher in patients with type 2 diabetes (p = 0.008), and CKD was significantly associated with BC in patients with type 2 diabetes (p = 0.032). A biomarker model, incorporating two serum (monocyte chemoattractant protein 1 and vascular endothelial growth factor) and three urine (interleukin 6, cytokeratin 18, and cytokeratin 8) proteins, predicted incidence of BC with an Area Under the Curve (AUC) of 0.84 in individuals with type 2 diabetes. In people without diabetes, the AUC was 0.66. CONCLUSIONS: We demonstrate the potential clinical utility of a biomarker panel, which includes proteins related to BC pathogenesis and type 2 diabetes, for monitoring risk of BC in patients with type 2 diabetes. Earlier urology referral of patients with type 2 diabetes will improve outcomes for these patients. TRIAL REGISTRATION: http://www.isrctn.com/ISRCTN25823942.

Thoracic ultrasound competence for ultrasound guided pleural procedures: The creation and validation of an assessment tool for use in the certification of basic thoracic ultrasound competence.

OBJECTIVES: Focused thoracic ultrasound (TUS) provides an increased safety profile when undertaking invasive pleural procedures. This has led to the requirement for defined curricula, high quality teaching and robust, validated assessment tools among physicians to ensure patient safety and clinical excellence. Current UK practice is based almost exclusively on expert consensus, but assessment methods employed have been shown to have low reliability and validity and are potentially open to bias. As a result, several assessment tools have been developed, although each has its own limitations. METHODS: This study aimed to develop and validate an assessment tool corresponding to those skills associated with the most basic level of practice, defined recently as an emergency level operator in the British Thoracic Society Training Standards for Thoracic Ultrasound. RESULTS: A total of 27 candidates were enrolled by two examiners based in Belfast and Oxford over a 10-month period between February and November 2019. Mean score of the inexperienced group was 44.3 (95% CI 39.2-49.4, range 28-54) compared with 74.9 (95% CI 72.8-77, range 64-80) in the experienced group providing an estimated mean difference of 30.7 between the two groups (95% CI 24.7-36.7; p < .001). CONCLUSIONS: This tool appears to discriminate between trainees with limited experience of TUS performance and those with no experience. It has the potential to form part of the assessment strategy for trainees in the United Kingdom and beyond, alongside well established assessment tools in postgraduate training.

Design and implementation of an online admissions interview for selection to nursing and midwifery programmes: a partnership approach.

BACKGROUND: The recent surge in applications to nursing in the United Kingdom together with the shift towards providing virtual interviews through the use of video platforms has provided an opportunity to review selection methodologies to meet a new set of challenges. However there remains the requirement to use selection methods which are evidence-based valid and reliable even under these new challenges. METHOD: This paper reports an evaluation study of applicants to nursing and midwifery and reports on how to plan and use online interviews for in excess of 3000 applicants to two schools of nursing in Northern Ireland. Data is reported from Participants, Assessors and Administrators who were asked to complete an online evaluation using Microsoft Forms. RESULTS: A total of 1559 participants completed the questionnaire. The majority were aged 17-20. The findings provide evidence to support the validity and reliability of the online interview process. Importantly the paper reports on the design and implementation of a fully remote online interview process that involved a collaboration with two schools of nursing without compromising the rigour of the admissions process. The paper provides practical, quantitative, and qualitative reasons for concluding that the online remote selection process generated reliable data to support its use in the selection of candidates to nursing and midwifery. CONCLUSION: There are significant challenges in moving to online interviews and the paper discusses the challenges and reflects on some of the broader issues associated with selection to nursing and midwifery. The aim of the paper is to provide a platform for discussion amongst other nursing schools who might be considering major changes to their admissions processes.

The discourse of design: Patterns of TPACK Contribution during pre-service teacher learning design conversations.

Analysing pre-service teachers' learning design conversations in relation to Technological Pedagogical and Content Knowledge (TPACK) framework to understand their learning design practices has remained unexplored. This paper presents findings from a study of pre-service teachers' design discourses that identified how TPACK elements were used during their collaborative design of technology-enhanced lessons. Through thematic analysis of 81 design conversations in two cycles, it was found that pre-service teachers discussed design related issues, TPACK elements, and context in their design conversations with dominant references to design-related issues, substantial occurrences of single TPACK elements, and lower frequencies of integrated TPACK elements and context. Practical recommendations and a Design-TPACK or 'D-TPACK' framework were proposed to support pre-service teachers' learning design practices.

Investigating the physical activity, health, wellbeing, social and environmental effects of a new urban greenway: a natural experiment (the PARC study).

BACKGROUND: Evidence for the health benefits of urban green space tends to stem from small, short-term quasi-experimental or cross-sectional observational research, whilst evidence from intervention studies is sparse. The development of an urban greenway (9 km running along 3 rivers) in Northern Ireland provided the opportunity to conduct a natural experiment. This study investigated the public health impact of the urban greenway on a range of physical activity, health, wellbeing, social, and perceptions of the environment outcomes. METHODS: A repeated cross-sectional household survey of adult residents (aged ≥16 years) who lived ≤1-mile radius of the greenway (intervention sample) and > 1-mile radius of the greenway (control sample) was conducted pre (2010/2011) and 6-months post implementation (2016/2017). We assessed changes in outcomes pre- and post-intervention follow-up including physical activity behaviour (primary outcome measure: Global Physical Activity Questionnaire), quality of life, mental wellbeing, social capital and perceptions of the built environment. Linear regression was used to calculate the mean difference between post-intervention and baseline measures adjusting for age, season, education, car ownership and deprivation. Multi-level models were fitted using a random intercept at the super output area (smallest geographical unit) to account for clustering within areas. The analyses were stratified by distance from the greenway and deprivation. We assessed change in the social patterning of outcomes over time using an ordered logit to make model-based outcome predictions across strata. RESULTS: The mean ages of intervention samples were 50.3 (SD 18.9) years at baseline (n = 1037) and 51.7 (SD 19.1) years at follow-up (n = 968). Post-intervention, 65% (adjusted OR 0.60, 95% CI 0.35 to 1.00) of residents who lived closest to the greenway (i.e., ≤400 m) and 60% (adjusted OR, 0.64 95% CI 0.41 to 0.99) who lived furthest from the greenway (i.e.,≥1200 m) met the physical activity guidelines - 68% of the intervention sample met the physical activity guidelines before the intervention. Residents in the most deprived quintiles had a similar reduction in physical activity behaviour as residents in less deprived quintiles. Quality of life at follow-up compared to baseline declined and this decline was significantly less than in the control area (adjusted differences in mean EQ5D: -11.0 (95% CI - 14.5 to - 7.4); - 30.5 (95% CI - 37.9 to - 23.2). Significant change in mental wellbeing was not observed despite improvements in some indicators of social capital. Positive perceptions of the local environment in relation to its attractiveness, traffic and safety increased. CONCLUSIONS: Our findings illustrate the major challenge of evaluating complex urban interventions and the difficulty of capturing and measuring the network of potential variables that influence or hinder meaningful outcomes. The results indicate at this stage no intervention effect for improvements in population-level physical activity behaviour or mental wellbeing. However, they show some modest improvements for secondary outcomes including positive perceptions of the environment and social capital constructs. The public health impact of urban greenways may take a longer period of time to be realised and there is a need to improve evaluation methodology that captures the complex systems nature of urban regeneration.

COVID-19: The regional impact of COVID-19 on the certification of vision impairment in Northern Ireland.

PURPOSE: In this paper we highlight the impact which the disruption of secondary care ophthalmic services, resulting from COVID-19, has had on Sight Impairment (SI) and Severe Sight Impairment (SSI) certification in Northern Ireland. METHODS: Regional data on SI and SSI certification in the period after the onset of the lockdown (19 March 2020-18 June 2020) were compared to the period immediately before lockdown (1 January 2020-18 March 2020) and to the same periods in 2019. Change documented was compared to post-lockdown reductions in primary and secondary ophthalmic care activity. RESULTS: In 2019, during the 3-month period (19 March 2019-18 June 2019), 115 individuals were certified as sight impaired (SI 36, SSI 75, unspecified 4). Of those certified, 65 were female, 49 male. Principal causes of certification were: Age-related macular degeneration (AMD) (N = 45), glaucoma (N = 20) and diabetic eye disease (DED) (N = 10). Mean VA, recorded from the better eye of those certified, was 0.96 LogMAR. In the 3 months following the onset of lockdown (19 March 2020-18 June 2020), only 37 individuals were certified (SI 6, SSI 31), 12 female and 25 male. AMD was the most frequent cause of sight impairment (N = 20). There were only two DED certifications and one due to glaucoma. Mean VA in the better eye of those certified was 1.15LogMAR. The numbers of CVI certifications completed following the introduction of COVID-19 lockdown fell by 68%, compared to the 2019 data. There was a significant reduction in the proportion of female certifications (p = 0.01), and in certifications due to glaucoma (p = 0.02). The proportion of those certified as SSI as opposed to SI in the period after the onset of lockdown rose from 68% in 2019 to 84% in 2020. The mean VA of those certified in the period after the onset of lockdown, when compared to those certified in the other three periods, was worse by between 0.21 and 0.19 LogMAR (p = 0.06). Reductions reflected change in overall primary and secondary ophthalmic care activity. CONCLUSIONS: It is inconceivable that COVID-19 has reduced the incidence of sight-threatening eye disease. We must therefore assume that a flood of newly presenting sight loss will present once the pandemic has passed. New presentations will include those who would normally have attended during the lockdown period, and patients who, had they accessed ophthalmic care at the appropriate time, would have been saved from severe levels of blindness. The implications of the predicted increase in demand for medical, social and low vision related services are huge.

Non-inferiority randomised phase 3 trial comparing two radiation schedules (single vs. five fractions) in malignant spinal cord compression.

BACKGROUND: The optimal EBRT schedule for MSCC is undetermined. Our aim was to determine whether a single fraction (SF) was non-inferior to five daily fractions (5Fx), for functional motor outcome. METHODS: Patients not proceeding with surgical decompression in this multicentre non-inferiority, Phase 3 trial were randomised to 10 Gy/SF or 20 Gy/5Fx. A change in mobility from baseline to 5 weeks for each patient, was evaluated by a Modified Tomita score: 1 = 'Walk unaided', 2 = 'With walking aid' and 3 = 'Bed-bound'. The margin used to establish non-inferiority was a detrimental change of -0.4 in the mean difference between arms. RESULTS: One-hundred and twelve eligible patients were enrolled. Seventy-three patients aged 30-87 were evaluated for the primary analysis. The 95% CI for the difference in the mean change in mobility scores between arms was -0.12 to 0.6. Since -0.4 is not included in the interval, there is evidence that 10 Gy/SF is non-inferior to 20 Gy/5Fx. One grade 3 AE was reported in the 5Fx arm. Twelve (26%) patients in the 5Fx arm had a Grade 2-3 AE compared with six (11%) patients in the SF arm (p = 0.093). CONCLUSION: For mobility preservation, one 10-Gy fraction is non-inferior to 20 Gy in five fractions, in patients with MSCC not proceeding with surgical decompression. CLINICAL TRIAL REGISTRATION: Cancer Trials Ireland ICORG 05-03; NCT00968643; EU-20952.

Elucidation of a Copper Binding Site in Proinsulin C-peptide and Its Implications for Metal-Modulated Activity.

The connecting peptide (C-peptide) is a hormone with promising health benefits in ameliorating diabetes-related complications, yet mechanisms remain elusive. Emerging studies point to a possible dependence of peptide activity on bioavailable metals, particularly Cu(II) and Zn(II). However, little is known about the chemical nature of the interactions, hindering advances in its therapeutic applications. This work uncovers the Cu(II)-binding site in C-peptide that may be key to understanding its metal-dependent function. A combination of spectroscopic studies reveal that Cu(II) and Zn(II) bind to C-peptide at specific residues in the N-terminal region of the peptide and that Cu(II) is able to displace Zn(II) for C-peptide binding. The data point to a Cu(II)-binding site consisting of 1N3O square-planar coordination that is entropically driven. Furthermore, the entire random coil peptide sequence is needed for specific metal binding as mutations and truncations reshuffle the coordinating residues. These results expand our understanding of how metals influence hormone activity and facilitate the discovery and validation of both new and established paradigms in peptide biology.

The burden of familial chylomicronemia syndrome in Canadian patients.

BACKGROUND: Familial chylomicronemia syndrome (FCS) is a rare autosomal recessive disorder characterized by persistent extreme hypertriglyceridemia as a result of lipoprotein lipase deficiency. Canada is an important region for FCS research due to the high prevalence rates. The burden of illness and quality of life of Canadian patients, however, have been inadequately addressed in the literature. OBJECTIVE: To understand the burden of illness of FCS on Canadian patients' lives. METHODS: IN-FOCUS is a global web-based survey open to patients with FCS, including patients in Canada. This survey captured information on diagnostic experience, symptoms, comorbidities, disease management, and impact on multiple life dimensions. RESULTS: A total of 37 Canadian patients completed the IN-FOCUS survey. Patients saw a mean of 4 physicians before their FCS diagnosis despite 89% reporting an FCS family history. Patients experience multiple physical, emotional, and cognitive symptoms in addition to FCS-related comorbidities. Notably, 35% of those who answered the survey have experienced acute pancreatitis, averaging 14 lifetime episodes per patient. In the preceding 12 months, 46% of patients had an FCS-related hospitalization, averaging 3 nights' stay. All respondents restricted fat intake, with 27% following an extremely low-fat diet. Despite this, 100% of patients reported fasting TG levels above the normal range. FCS impacted career choice in nearly all patients (97%) and employment status in all patients who were employed part time, disabled, or homemakers, causing many (> 75%) to choose careers below their level of abilities. Furthermore, 2/3 of patients reported FCS had a significant impact on their decision regarding whether to have children. Most report significant interference with their emotional/mental well-being, social relationships, and the majority were concerned about the long-term impact of FCS on their health (89%). CONCLUSIONS: This study provides the first and largest study to investigate the multi-faceted psychosocial and cognitive impacts of FCS on patients. Canadian patients with FCS experience significant multi-faceted burdens that diminish their quality of life, employment opportunities, social relationships, and mental/emotional well-being. These results highlight the need for greater disease awareness, improved clinical diagnosis, broader clinical management for heterogenous symptoms, and more effective treatment options for FCS.

Analysis of Metal Effects on C-Peptide Structure and Internalization.

The connecting peptide (C-peptide) has received increased attention for its potential therapeutic effects in ameliorating illnesses such as kidney disease and diabetes. Although the mechanism of C-peptide signaling remains elusive, evidence supports its internalization and intracellular function. Emerging research is uncovering the diverse biological roles metals play in controlling and affecting the function of bioactive peptides. The work presented herein investigates interactions between C-peptide and first-row d-block transition metals, as well as their effects on C-peptide internalization into cells. Through spectroscopic techniques, it is demonstrated that CrIII , CuII , and ZnII bind to C-peptide with differing stoichiometries and biologically relevant affinities. In addition, metal binding elicits both subtle changes in secondary structure and inhibits adoption of an α-helical character in environments where the dielectric constants are reduced. This study shows how metal ions can modulate peptide hormone activity through subtle structural changes to disrupt cellular uptake.

A retrospective study of radiation dose measurements comparing different cath lab X-ray systems in a sample population of patients undergoing percutaneous coronary intervention for chronic total occlusions.

OBJECTIVES: A retrospective study was performed to investigate if the generation of X-ray system used was an independent factor for radiation dose in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). BACKGROUND: PCI procedures for CTOs are known to be associated with higher doses of radiation. The authors suspected progressive reductions in radiation doses for CTO PCI as newer X-ray systems were introduced into clinical practice. METHODS: Procedures performed over a five-year period by three interventional cardiologists were retrospectively reviewed. Five different X-ray systems were used across three hospital sites. These included: Axiom Artis and Coroskop HIP (both Siemens), Innova (GE), Allura Xper FD 10, and Allura Clarity FD 10 (both Philips). Procedural and demographic data including body mass index (BMI; kg/m2 ), fluoroscopy time (min), and dose area product (DAP; cGycm2 ) were collated for each procedure. Statistical analysis was performed to compare the influence each X-ray system would have on DAP values after BMI and fluoroscopy time were controlled for. RESULTS: In total, 860 procedures were analyzed. Mean fluoroscopy time was 40.00 ± 19.99 min, mean BMI was 29.90 ± 5.13 kg/m2 , mean DAP 11,980 ± 7,947 cGycm2 . Log values of DAP were used to normalize results in a general linear model. A significant statistical difference in DAP between X-ray systems was demonstrated after fluoroscopy time and BMI were controlled for (P ≤ 0.001). CONCLUSION: There is a significant impact on DAP values resulting from the generation of X-ray system used, measured during PCI for CTOs, with the most modern systems producing the lowest radiation doses.

Calibration of confidence and assessed clinical skills competence in undergraduate paediatric OSCE scenarios: a mixed methods study.

BACKGROUND: The relationship between confidence and competence in clinical skills development is complex but important. This study aims to determine undergraduate paediatric student confidence in performing three common paediatric clinical skills framed as Objective Structured Clinical Examination (OSCE) scenarios and to compare this with subsequent assessed performance. The study also aims to explore possible barriers to successful paediatric skills completion. METHODS: A mixed-methods study was conducted on medical students. Cross-sectional questionnaire data relating to confidence in performing a number of paediatric skills were compared with assessed paediatric skills competency. Focus groups were carried out to identify themes in paediatric skills completion to triangulate this data. RESULTS: Eighty-five medical students participated in the study. Students had high levels of pre-test confidence in their ability to perform paediatrics skills. However agreement between pre-test confidence and subsequent task performance was poor and students had significantly greater belief in their skills ability than was subsequently demonstrated. Focus groups identified paediatric skills complexity, conflicting teaching and having limited supervised skills opportunities and as being possible contributory factors to this discrepancy. CONCLUSIONS: Student paediatric skills confidence is not matched by performance. The reasons for this are diverse but mostly modifiable. A major factor is the lack of supervised skills experience with appropriate feedback to support students in learning to calibrate their confidence against their competence. A number of recommendations are made including the introduction of formative assessment opportunities.

Structural and Biochemical Characterization of Organotin and Organolead Compounds Binding to the Organomercurial Lyase MerB Provide New Insights into Its Mechanism of Carbon-Metal Bond Cleavage.

The organomercurial lyase MerB has the unique ability to cleave carbon-Hg bonds, and structural studies indicate that three residues in the active site (C96, D99, and C159 in E. coli MerB) play important roles in the carbon-Hg bond cleavage. However, the role of each residue in carbon-metal bond cleavage has not been well-defined. To do so, we have structurally and biophysically characterized the interaction of MerB with a series of organotin and organolead compounds. Studies with two known inhibitors of MerB, dimethyltin (DMT) and triethyltin (TET), reveal that they inhibit by different mechanisms. In both cases the initial binding is to D99, but DMT subsequently binds to C96, which induces a conformation change in the active site. In contrast, diethyltin (DET) is a substrate for MerB and the SnIV product remains bound in the active site in a coordination similar to that of HgII following cleavage of organomercurial compounds. The results with analogous organolead compounds are similar in that trimethyllead (TML) is not cleaved and binds only to D99, whereas diethyllead (DEL) is a substrate and the PbIV product remains bound in the active site. Binding and cleavage is an exothermic reaction, while binding to D99 has negligible net heat flow. These results show that initial binding of organometallic compounds to MerB occurs at D99 followed, in some cases, by cleavage and loss of the organic moieties and binding of the metal ion product to C96, D99, and C159. The N-terminus of MerA is able to extract the bound PbVI but not the bound SnIV. These results suggest that MerB could be utilized for bioremediation applications, but certain organolead and organotin compounds may present an obstacle by inhibiting the enzyme.

Social Cognition, Child Neglect, and Child Injury Risk: The Contribution of Maternal Social Information Processing to Maladaptive Injury Prevention Beliefs Within a High-Risk Sample.

Objective: Inadequate supervision has been linked to children's injuries. Parental injury prevention beliefs may play a role in supervision, yet little theory has examined the origins of such beliefs. This study examined whether mothers who perpetrated child neglect, who as a group provide inadequate supervision, have more maladaptive beliefs. Then, it tested a social information processing (SIP) model for explaining these beliefs. Methods: SIP and injury prevention beliefs were assessed in disadvantaged mothers of preschoolers (N = 145), half with child neglect histories. Results: The neglect group exhibited significantly more maladaptive injury prevention beliefs than comparisons. As predicted, SIP was linked to beliefs that may increase injury risk, even after accounting for relevant sociodemographic variables. Conclusions: Findings support the link of beliefs to injury risk and suggest that specific cognitive problems may underlie these beliefs. Future work should further validate this model, which may inform enhancements to prevention efforts.

Structural and Biochemical Characterization of a Copper-Binding Mutant of the Organomercurial Lyase MerB: Insight into the Key Role of the Active Site Aspartic Acid in Hg-Carbon Bond Cleavage and Metal Binding Specificity.

In bacterial resistance to mercury, the organomercurial lyase (MerB) plays a key role in the detoxification pathway through its ability to cleave Hg-carbon bonds. Two cysteines (C96 and C159; Escherichia coli MerB numbering) and an aspartic acid (D99) have been identified as the key catalytic residues, and these three residues are conserved in all but four known MerB variants, where the aspartic acid is replaced with a serine. To understand the role of the active site serine, we characterized the structure and metal binding properties of an E. coli MerB mutant with a serine substituted for D99 (MerB D99S) as well as one of the native MerB variants containing a serine residue in the active site (Bacillus megaterium MerB2). Surprisingly, the MerB D99S protein copurified with a bound metal that was determined to be Cu(II) from UV-vis absorption, inductively coupled plasma mass spectrometry, nuclear magnetic resonance, and electron paramagnetic resonance studies. X-ray structural studies revealed that the Cu(II) is bound to the active site cysteine residues of MerB D99S, but that it is displaced following the addition of either an organomercurial substrate or an ionic mercury product. In contrast, the B. megaterium MerB2 protein does not copurify with copper, but the structure of the B. megaterium MerB2-Hg complex is highly similar to the structure of the MerB D99S-Hg complexes. These results demonstrate that the active site aspartic acid is crucial for both the enzymatic activity and metal binding specificity of MerB proteins and suggest a possible functional relationship between MerB and its only known structural homologue, the copper-binding protein NosL.