Investigating the biosynthesis of heam d1 in pseudomonas aeruginosa: a cofactor for dissimilatory nitrite reductase.

PhDHaem d1 is a modified tetrapyrrole unique to the periplasmic enzyme nitrite reductase where it acts in catalysing the reduction of nitrite (NO2 -) to nitric oxide (NO), as part of denitrification. As with all modified tetrapyrroles, haem d1 shares a common biosynthetic pathway starting from 5-aminolaevulinic acid (ALA), up to the formation of uroporphyrinogen III (UIII). UIII is the branch point from which the pathway diverges to form the various metallo-prosthetic groups including vitamin B12. The precise mechanism of transformation from UIII to haem d1 is unknown. Examination of both structures shows a requirement of methylation at C2 and C7; decarboxylation of acetate side chains at C12 and C18; loss of propionic side chains at C3 and C8 with subsequent oxidation at C3 and C8; dehydrogenation of C17 propionate side chain gives the acrylate substituent and ferrochelation. Of particular interest is the addition of oxygen to the macrocycle under anaerobic conditions. Only one other intermediate, compound 800, has been isolated thus far but it is unknown how it is part of the pathway. Genetic studies have implicated seven nir genes, called nirF, nirD, nirL, nirG, nirH, nirJ and nirE, are required for haem d1 biogenesis. Here, experiments and data show for the first time that it proceeds from UIII to precorrin-2 using the enzyme NirE. This study is the first to experimentally show the production of precorrin-2 as part of the pathway using anaerobic enzyme assays. This thesis illustrates the intense work that has focused on cloning the genes individually and as multigene constructs in an attempt to characterise the proteins overproduced. Heterologous expression in Escherichia coli has been successful as well as the development of a homologous expression system in Pseudomonas aeruginosa. The data represented shows the various aspects entailed in the optimisation of overproduction and the stabilisation of the Nir proteins. It also documents the first concerted attempt to take the operon and engineer strains to make haem d1 both in vivo and in vitro, using the Link and Lock method to clone the nir genes consecutively into a plasmid. This thesis therefore provides a foundation for understanding the molecular biology and biochemistry of haem d1 synthesis for the future

'You get looked at like you're failing': A reflexive thematic analysis of experiences of mental health and wellbeing support for NHS staff

Staff in the National Health Service (NHS) are under considerable strain, exacerbated by the COVID-19 pandemic; whilst NHS Trusts provide a variety of health and wellbeing support services, there has been little research investigating staff perceptions of these services. We interviewed 48 healthcare workers from 18 NHS Trusts in England about their experiences of workplace health and wellbeing support during the pandemic. Reflexive thematic analysis identified that perceived stigma around help-seeking, and staffing shortages due to wider socio-political contexts such as austerity, were barriers to using support services. Visible, caring leadership at all levels (CEO to line managers), peer support, easily accessible services, and clear communication about support offers were enablers. Our evidence suggests Trusts should have active strategies to improve help-seeking, such as manager training and peer support facilitated by building in time for this during working hours, but this will require long-term strategic planning to address workforce shortages

NHS CHECK: protocol for a cohort study investigating the psychosocial impact of the COVID-19 pandemic on healthcare workers

INTRODUCTION: The COVID-19 pandemic has had profound effects on the working lives of healthcare workers (HCWs), but the extent to which their well-being and mental health have been affected remains unclear. This longitudinal cohort study aims to recruit a cohort of National Health Service (NHS) HCWs, conducting surveys at regular intervals to provide evidence about the prevalence of symptoms of mental disorders, and investigate associated factors such as occupational contexts and support interventions available. METHODS AND ANALYSIS: All staff, students and volunteers working in the 18 participating NHS Trusts in England will be sent emails inviting them to complete a survey at baseline, with email invitations for the follow-up surveys sent 6 months and 12 months later. Opening in late April 2020, the baseline survey collects data on demographics, occupational/organisational factors, experiences of COVID-19, validated measures of symptoms of poor mental health (eg, depression, anxiety, post-traumatic stress disorder), and constructs such as resilience and moral injury. These surveys will be complemented by in-depth psychiatric interviews with a sample of HCWs. Qualitative interviews will also be conducted, to gain deeper understanding of the support programmes used or desired by staff, and facilitators and barriers to accessing such programmes. ETHICS AND DISSEMINATION: Ethical approval for the study was granted by the Health Research Authority (reference: 20/HRA/210, IRAS: 282686) and local Trust Research and Development approval. Cohort data are collected via Qualtrics online survey software, pseudonymised and held on secure university servers. Participants are aware that they can withdraw from the study at any time, and there is signposting to support services if participants feel they need it. Only those consenting to be contacted about further research will be invited to participate in further components. Findings will be rapidly shared with NHS Trusts, and via academic publications in due course

Prevalence of post-traumatic stress disorder and common mental disorders in health-care workers in England during the COVID-19 pandemic: a two-phase cross-sectional study

BACKGROUND: Previous studies on the impact of the COVID-19 pandemic on the mental health of health-care workers have relied on self-reported screening measures to estimate the point prevalence of common mental disorders. Screening measures, which are designed to be sensitive, have low positive predictive value and often overestimate prevalence. We aimed to estimate prevalence of common mental disorders and post-traumatic stress disorder (PTSD) among health-care workers in England using diagnostic interviews. METHODS: We did a two-phase, cross-sectional study comprising diagnostic interviews within a larger multisite longitudinal cohort of health-care workers (National Health Service [NHS] CHECK; n=23 462) during the COVID-19 pandemic. In the first phase, health-care workers across 18 NHS England Trusts were recruited. Baseline assessments were done using online surveys between April 24, 2020, and Jan 15, 2021. In the second phase, we selected a proportion of participants who had responded to the surveys and conducted diagnostic interviews to establish the prevalence of mental disorders. The recruitment period for the diagnostic interviews was between March 1, 2021 and Aug 27, 2021. Participants were screened with the 12-item General Health Questionnaire (GHQ-12) and assessed with the Clinical Interview Schedule-Revised (CIS-R) for common mental disorders or were screened with the 6-item Post-Traumatic Stress Disorder Checklist (PCL-6) and assessed with the Clinician Administered PTSD Scale for DSM-5 (CAPS-5) for PTSD. FINDINGS: The screening sample contained 23 462 participants: 2079 participants were excluded due to missing values on the GHQ-12 and 11 147 participants due to missing values on the PCL-6. 243 individuals participated in diagnostic interviews for common mental disorders (CIS-R; mean age 42 years [range 21-70]; 185 [76%] women and 58 [24%] men) and 94 individuals participated in diagnostic interviews for PTSD (CAPS-5; mean age 44 years [23-62]; 79 [84%] women and 15 [16%] men). 202 (83%) of 243 individuals in the common mental disorders sample and 83 (88%) of 94 individuals in the PTSD sample were White. GHQ-12 screening caseness for common mental disorders was 52·8% (95% CI 51·7-53·8). Using CIS-R diagnostic interviews, the estimated population prevalence of generalised anxiety disorder was 14·3% (10·4-19·2), population prevalence of depression was 13·7% (10·1-18·3), and combined population prevalence of generalised anxiety disorder and depression was 21·5% (16·9-26·8). PCL-6 screening caseness for PTSD was 25·4% (24·3-26·5). Using CAPS-5 diagnostic interviews, the estimated population prevalence of PTSD was 7·9% (4·0-15·1). INTERPRETATION: The prevalence estimates of common mental disorders and PTSD in health-care workers were considerably lower when assessed using diagnostic interviews compared with screening tools. 21·5% of health-care workers met the threshold for diagnosable mental disorders, and thus might benefit from clinical intervention. FUNDING: UK Medical Research Council; UCL/Wellcome; Rosetrees Trust; NHS England and Improvement; Economic and Social Research Council; National Institute for Health and Care Research (NIHR) Biomedical Research Centre at the Maudsley and King's College London (KCL); NIHR Protection Research Unit in Emergency Preparedness and Response at KCL

Psychosocial impact of the COVID-19 pandemic on 4378 UK healthcare workers and ancillary staff: initial baseline data from a cohort study collected during the first wave of the pandemic

OBJECTIVES: This study reports preliminary findings on the prevalence of, and factors associated with, mental health and well-being outcomes of healthcare workers during the early months (April-June) of the COVID-19 pandemic in the UK. METHODS: Preliminary cross-sectional data were analysed from a cohort study (n=4378). Clinical and non-clinical staff of three London-based NHS Trusts, including acute and mental health Trusts, took part in an online baseline survey. The primary outcome measure used is the presence of probable common mental disorders (CMDs), measured by the General Health Questionnaire. Secondary outcomes are probable anxiety (seven-item Generalised Anxiety Disorder), depression (nine-item Patient Health Questionnaire), post-traumatic stress disorder (PTSD) (six-item Post-Traumatic Stress Disorder checklist), suicidal ideation (Clinical Interview Schedule) and alcohol use (Alcohol Use Disorder Identification Test). Moral injury is measured using the Moray Injury Event Scale. RESULTS: Analyses showed substantial levels of probable CMDs (58.9%, 95% CI 58.1 to 60.8) and of PTSD (30.2%, 95% CI 28.1 to 32.5) with lower levels of depression (27.3%, 95% CI 25.3 to 29.4), anxiety (23.2%, 95% CI 21.3 to 25.3) and alcohol misuse (10.5%, 95% CI 9.2 to 11.9). Women, younger staff and nurses tended to have poorer outcomes than other staff, except for alcohol misuse. Higher reported exposure to moral injury (distress resulting from violation of one's moral code) was strongly associated with increased levels of probable CMDs, anxiety, depression, PTSD symptoms and alcohol misuse. CONCLUSIONS: Our findings suggest that mental health support for healthcare workers should consider those demographics and occupations at highest risk. Rigorous longitudinal data are needed in order to respond to the potential long-term mental health impacts of the pandemic

Prevalence of post-traumatic stress disorder and common mental disorders in health-care workers in England during the COVID-19 pandemic: a two-phase cross-sectional study

Background Previous studies on the impact of the COVID-19 pandemic on the mental health of health-care workers have relied on self-reported screening measures to estimate the point prevalence of common mental disorders. Screening measures, which are designed to be sensitive, have low positive predictive value and often overestimate prevalence. We aimed to estimate prevalence of common mental disorders and post-traumatic stress disorder (PTSD) among health-care workers in England using diagnostic interviews. Methods We did a two-phase, cross-sectional study comprising diagnostic interviews within a larger multisite longitudinal cohort of health-care workers (National Health Service [NHS] CHECK; n=23 462) during the COVID-19 pandemic. In the first phase, health-care workers across 18 NHS England Trusts were recruited. Baseline assessments were done using online surveys between April 24, 2020, and Jan 15, 2021. In the second phase, we selected a proportion of participants who had responded to the surveys and conducted diagnostic interviews to establish the prevalence of mental disorders. The recruitment period for the diagnostic interviews was between March 1, 2021 and Aug 27, 2021. Participants were screened with the 12-item General Health Questionnaire (GHQ-12) and assessed with the Clinical Interview Schedule-Revised (CIS-R) for common mental disorders or were screened with the 6-item Post-Traumatic Stress Disorder Checklist (PCL-6) and assessed with the Clinician Administered PTSD Scale for DSM-5 (CAPS-5) for PTSD. Findings The screening sample contained 23 462 participants: 2079 participants were excluded due to missing values on the GHQ-12 and 11 147 participants due to missing values on the PCL-6. 243 individuals participated in diagnostic interviews for common mental disorders (CIS-R; mean age 42 years [range 21–70]; 185 [76%] women and 58 [24%] men) and 94 individuals participated in diagnostic interviews for PTSD (CAPS-5; mean age 44 years [23–62]; 79 [84%] women and 15 [16%] men). 202 (83%) of 243 individuals in the common mental disorders sample and 83 (88%) of 94 individuals in the PTSD sample were White. GHQ-12 screening caseness for common mental disorders was 52·8% (95% CI 51·7–53·8). Using CIS-R diagnostic interviews, the estimated population prevalence of generalised anxiety disorder was 14·3% (10·4–19·2), population prevalence of depression was 13·7% (10·1–18·3), and combined population prevalence of generalised anxiety disorder and depression was 21·5% (16·9–26·8). PCL-6 screening caseness for PTSD was 25·4% (24·3–26·5). Using CAPS-5 diagnostic interviews, the estimated population prevalence of PTSD was 7·9% (4·0–15·1). Interpretation The prevalence estimates of common mental disorders and PTSD in health-care workers were considerably lower when assessed using diagnostic interviews compared with screening tools. 21·5% of health-care workers met the threshold for diagnosable mental disorders, and thus might benefit from clinical intervention

An Empirical Investigation of Exchange Rate Pass-Through in South Africa

This paper analyzes the degree to which fluctuations in the nominal exchange rate passthrough to consumer prices in South Africa. While the average pass-through is found to be low, evidence from a structural vector autoregression suggests it is much higher for nominal (versus real) shocks. Historical decompositions suggest that the nominal exchange rate depreciation up to November 2001 is attributable primarily to negative real shocks, which explains why CPIX (consumer price index excluding interest on mortgate bonds) inflation did not increase significantly until December 2001, when positive nominal shocks began to contribute to the depreciation.Producer prices;exchange rate, inflation, nominal exchange rate, relative prices, real exchange rate, effective exchange rate, price inflation, monetary policy, nominal effective exchange rate, exchange rate pass, exchange rate depreciation, price level, exchange rate fluctuations, real effective exchange rate, exchange rates, nominal exchange rate depreciation, exchange rate shocks, currency depreciation, inflation target, dollar exchange rate, inflationary pressures, effective exchange rates, money growth, aggregate demand, inflationary impact, real interest rates, currency devaluations, exchange rate depreciations, exchange rate shock, real exchange rate depreciation, relative price, exchange rate changes, rates of inflation, general level of prices