57 research outputs found

    SAGA1 and SAGA2 promote starch formation around proto-pyrenoids in Arabidopsis chloroplasts

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    The pyrenoid is a chloroplastic microcompartment in which most algae and some terrestrial plants condense the primary carboxylase, Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase) as part of a CO2-concentrating mechanism that improves the efficiency of CO2 capture. Engineering a pyrenoid-based CO2-concentrating mechanism (pCCM) into C3 crop plants is a promising strategy to enhance yield capacities and resilience to the changing climate. Many pyrenoids are characterized by a sheath of starch plates that is proposed to act as a barrier to limit CO2 diffusion. Recently, we have reconstituted a phase-separated “proto-pyrenoid” Rubisco matrix in the model C3 plant Arabidopsis thaliana using proteins from the alga with the most well-studied pyrenoid, Chlamydomonas reinhardtii [N. Atkinson, Y. Mao, K. X. Chan, A. J. McCormick, Nat. Commun.11, 6303 (2020)]. Here, we describe the impact of introducing the Chlamydomonas proteins StArch Granules Abnormal 1 (SAGA1) and SAGA2, which are associated with the regulation of pyrenoid starch biogenesis and morphology. We show that SAGA1 localizes to the proto-pyrenoid in engineered Arabidopsis plants, which results in the formation of atypical spherical starch granules enclosed within the proto-pyrenoid condensate and adjacent plate-like granules that partially cover the condensate, but without modifying the total amount of chloroplastic starch accrued. Additional expression of SAGA2 further increases the proportion of starch synthesized as adjacent plate-like granules that fully encircle the proto-pyrenoid. Our findings pave the way to assembling a diffusion barrier as part of a functional pCCM in vascular plants, while also advancing our understanding of the roles of SAGA1 and SAGA2 in starch sheath formation and broadening the avenues for engineering starch morphology

    Larval therapy for leg ulcers (VenUS II) : randomised controlled trial

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    Objective To compare the clinical effectiveness of larval therapy with a standard debridement technique (hydrogel) for sloughy or necrotic leg ulcers. Design Pragmatic, three armed randomised controlled trial. Setting Community nurse led services, hospital wards, and hospital outpatient leg ulcer clinics in urban and rural settings, United Kingdom. Participants 267 patients with at least one venous or mixed venous and arterial ulcer with at least 25% coverage of slough or necrotic tissue, and an ankle brachial pressure index of 0.6 or more. Interventions Loose larvae, bagged larvae, and hydrogel. Main outcome measures The primary outcome was time to healing of the largest eligible ulcer. Secondary outcomes were time to debridement, health related quality of life (SF-12), bacterial load, presence of meticillin resistant Staphylococcus aureus, adverse events, and ulcer related pain (visual analogue scale, from 0 mm for no pain to 150 mm for worst pain imaginable). Results Time to healing was not significantly different between the loose or bagged larvae group and the hydrogel group (hazard ratio for healing using larvae v hydrogel 1.13, 95% confidence interval 0.76 to 1.68; P=0.54). Larval therapy significantly reduced the time to debridement (2.31, 1.65 to 3.2; P<0.001). Health related quality of life and change in bacterial load over time were not significantly different between the groups. 6.7% of participants had MRSA at baseline. No difference was found between larval therapy and hydrogel in their ability to eradicate MRSA by the end of the debridement phase (75% (9/12) v 50% (3/6); P=0.34), although this comparison was underpowered. Mean ulcer related pain scores were higher in either larvae group compared with hydrogel (mean difference in pain score: loose larvae v hydrogel 46.74 (95% confidence interval 32.44 to 61.04), P<0.001; bagged larvae v hydrogel 38.58 (23.46 to 53.70), P<0.001). Conclusions Larval therapy did not improve the rate of healing of sloughy or necrotic leg ulcers or reduce bacterial load compared with hydrogel but did significantly reduce the time to debridement and increase ulcer pain. Trial registration Current Controlled Trials ISRCTN55114812 and National Research Register N0484123692

    Men, chronic illness and healthwork: accounts from male partners of women with endometriosis

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    Currently dominant in medical discourse, the concept of self‐management sees the responsibility for health and illness shift from the state to the individual. However, while this emphasis on individual responsibility and management has burgeoned, the role and status of partners and other family members in the management of chronic illness remains under‐theorised. While self‐management privileges individual responsibility for the management of chronic illness, the role of partners remains unclear. This paper utilises data from a study of heterosexual couples’ experiences of living with the chronic gynaecological condition endometriosis to explore how male partners engage in its day‐to‐day management. In all, 22 couples participated in in‐depth, semi‐structured interviews with each partner interviewed separately (n = 44). Data were analysed thematically and dyadically, informed by an interpretivist relational approach. The paper utilises the concept of healthwork to describe the illness work, everyday life work, biographical work and emotion work men engaged in. The paper demonstrates how the conceptual value of healthwork is enhanced by incorporating an analysis of the emotional effort required in managing chronic illness. The paper illustrates the value of investigating the role of partners in managing chronic illness to provide a fuller account of the distributed and relational nature of healthwork

    Methods for identifying surgical wound infection after discharge from hospital: a systematic review.

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    Background: Wound infections are a common complication of surgery that add significantly to the morbidity of patients and costs of treatment. The global trend towards reducing length of hospital stay post-surgery and the increase in day case surgery means that surgical site infections (SSI) will increasingly occur after hospital discharge. Surveillance of SSIs is important because rates of SSI are viewed as a measure of hospital performance, however accurate detection of SSIs post-hospital discharge is not straightforward. Methods: We conducted a systematic review of methods of post discharge surveillance for surgical wound infection and undertook a national audit of methods of post-discharge surveillance for surgical site infection currently used within United Kingdom NHS Trusts. Results: Seven reports of six comparative studies which examined the validity of post-discharge surveillance methods were located; these involved different comparisons and some had methodological limitations, making it difficult to identify an optimal method. Several studies evaluated automated screening of electronic records and found this to be a useful strategy for the identification of SSIs that occurred post discharge. The audit identified a wide range of relevant post-discharge surveillance programmes in England, Scotland and Wales and Northern Ireland; however, these programmes used varying approaches for which there is little supporting evidence of validity and/or reliability. Conclusion: In order to establish robust methods of surveillance for those surgical site infections that occur post discharge, there is a need to develop a method of case ascertainment that is valid and reliable post discharge. Existing research has not identified a valid and reliable method. A standardised definition of wound infection ( e. g. that of the Centres for Disease Control) should be used as a basis for developing a feasible, valid and reliable approach to defining post discharge SSI. At a local level, the method used to ascertain post discharge SSI will depend upon the purpose of the surveillance, the nature of available routine data and the resources available

    Disrupted prevention: Condom and contraception access and use among young adults during the initial months of the COVID-19 pandemic. An online survey

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    Background: The initial response to COVID-19 in the UK involved a rapid contraction of face-to-face sexual and reproductive health (SRH) services and widespread use of remote workarounds. This study sought to illuminate young people’s experiences of accessing and using condoms and contraception in the early months of the pandemic. Methods: We analysed data, including open-text responses, from an online survey conducted in June–July 2020 with a convenience sample of 2005 16–24-year-olds living in Scotland. Results: Among those who used condoms and contraception, one quarter reported that COVID-19 mitigation measures had made a difference to their access or use. Open-text responses revealed a landscape of disrupted prevention, including changes to sexual risk-taking and preventive practices, unwanted contraceptive pathways, unmet need for sexually transmitted infection (STI) testing, and switches from freely provided to commercially sold condoms and contraception. Pandemic-related barriers to accessing free condoms and contraception included: (1) uncertainty about the legitimacy of accessing SRH care and self-censorship of need; (2) confusion about differences between SRH care and advice received from healthcare professionals during the pandemic compared with routine practice; and (3) exacerbation of existing access barriers, alongside reduced social support and resources to navigate SRH care. Conclusions: Emerging barriers to STI and pregnancy prevention within the context of COVID-19 have the potential to undermine positive SRH practices, and widen inequalities, among young people. As SRH services are restored amid evolving pandemic restrictions, messaging to support navigation of condom and contraception services should be co-created with young people

    Images across Europe: The sending and receiving of sexual images and associations with interpersonal violence in young people's relationships

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    This article explores young people's experiences of sending and receiving sexual images and text messages (sexting) within their interpersonal relationships and the contexts in which this occurs. The article uses data from a recent Daphne funded project ‘Safeguarding teenagers' intimate relationships’ (STIR) involving a survey with 4564 young people aged between 14 and 17 in a number of schools across five countries in Europe. Findings reveal that experiences of sexting vary by country and gender. The study also found that young people who reported victimisation in their relationships were more likely to have sent a sext message than those who had not. The article points to the need for a more nuanced understanding of the varied contexts and experiences around sexting in order to better develop policy, practice and education in this area

    Single-molecule in vivo imaging of bacterial respiratory complexes indicates delocalized oxidative phosphorylation

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    Chemiosmotic energy coupling through oxidative phosphorylation (OXPHOS) is crucial to life, requiring coordinated enzymes whose membrane organization and dynamics are poorly understood. We quantitatively explore localization, stoichiometry, and dynamics of key OXPHOS complexes, functionally fluorescent protein-tagged, in Escherichia coli using low-angle fluorescence and superresolution microscopy, applying single-molecule analysis and novel nanoscale co-localization measurements. Mobile 100-200nm membrane domains containing tens to hundreds of complexes are indicated. Central to our results is that domains of different functional OXPHOS complexes do not co-localize, but ubiquinone diffusion in the membrane is rapid and long-range, consistent with a mobile carrier shuttling electrons between islands of different complexes. Our results categorically demonstrate that electron transport and proton circuitry in this model bacterium are spatially delocalized over the cell membrane, in stark contrast to mitochondrial bioenergetic supercomplexes. Different organisms use radically different strategies for OXPHOS membrane organization, likely depending on the stability of their environment
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