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Although imaging of the living retina with adaptive optics scanning light ophthalmoscopy (AOSLO) provides microscopic access to individual cells, such as photoreceptors, retinal pigment epithelial cells, and blood cells in the retinal vasculature, other important cell classes, such as retinal ganglion cells, have proven much more challenging to image. The near transparency of inner retinal cells is advantageous for vision, as light must pass through them to reach the photoreceptors, but it has prevented them from being directly imaged in vivo. Here we show that the individual somas of neurons within the retinal ganglion cell (RGC) layer can be imaged with a modification of confocal AOSLO, in both monkeys and humans. Human images of RGC layer neurons did not match the quality of monkey images for several reasons, including safety concerns that limited the light levels permissible for human imaging. We also show that the same technique applied to the photoreceptor layer can resolve ambiguity about cone survival in age-related macular degeneration. The capability to noninvasively image RGC layer neurons in the living eye may one day allow for a better understanding of diseases, such as glaucoma, and accelerate the development of therapeutic strategies that aim to protect these cells. This method may also prove useful for imaging other structures, such as neurons in the brain.

Cohorts of severely ill patients with COVID-19 have been described in several countries around the globe, but to date there have been few published reports from the United Kingdom (UK). Understanding the characteristics of the affected population admitted to intensive care units (ICUs) in the UK is crucial to inform clinical decision making, research and planning for future waves of infection. We conducted a prospective observational cohort study of all patients with COVID-19 admitted to a large UK ICU from March to May 2020 with follow-up to June 2020. Data were collected from health records using a standardised template. We used multivariable logistic regression to analyse the factors associated with ICU survival. Of the 156 patients included, 112 (72%) were male, 89 (57%) were overweight or obese, 68 (44%) were from ethnic minorities, and 89 (57%) were aged over 60 years of age. 136 (87%) received mechanical ventilation, 77 (57% of those intubated) were placed in the prone position and 95 (70% of those intubated) received neuromuscular blockade. 154 (99%) patients required cardiovascular support and 44 (28%) required renal replacement therapy. Of the 130 patients with completed ICU episodes, 38 (29%) died and 92 (71%) were discharged alive from ICU. In multivariable models, age (OR 1.13 [95% CI 1.07-1.21]), obesity (OR 3.06 [95% CI 1.16-8.74]), lowest P/F ratio on the first day of admission (OR 0.82 [95% CI 0.67-0.98]) and PaCO2 (OR 1.52 [95% CI 1.01-2.39]) were independently associated with ICU death. Age, obesity and severity of respiratory failure were key determinants of survival in this cohort. Multiorgan failure was prevalent. These findings are important for guiding future research and should be taken into consideration during future healthcare planning in the UK.

Pioneer transcription factors can engage nucleosomal DNA, which leads to local chromatin remodeling and to the establishment of transcriptional competence. However, the impact of enhancer priming by pioneer factors on the temporal control of gene expression and on mitotic memory remains unclear. Here we employ quantitative live imaging methods and mathematical modeling to test the effect of the pioneer factor Zelda on transcriptional dynamics and memory in Drosophila embryos. We demonstrate that increasing the number of Zelda binding sites accelerates the kinetics of nuclei transcriptional activation regardless of their transcriptional past. Despite its known pioneering activities, we show that Zelda does not remain detectably associated with mitotic chromosomes and is neither necessary nor sufficient to foster memory. We further reveal that Zelda forms sub-nuclear dynamic hubs where Zelda binding events are transient. We propose that Zelda facilitates transcriptional activation by accumulating in microenvironments where it could accelerate the duration of multiple pre-initiation steps. Zelda is a pioneer factor that regulates transcription in Drosophila embryos. Here, the authors use quantitative live imaging and mathematical modeling to measure the effect of Zelda on transcriptional dynamics and memory, observing temporal control of gene expression by Zelda through transient interactions in hubs.

Background: Health departments have been increasingly called upon to monitor healthcare associated-infections (HAIs) at the hospital- or facility-level and provide targeted assistance when high rates are identified. Health department capacity to effectively respond to these types of signals depends not only on technical expertise but also the legal and regulatory authority to intervene. Methods: We reviewed annual reports describing HAI and antibiotic resistance (HAI/AR) activities from CDC-funded HAI/AR programs for August 2017 through July 2018. We performed a qualitative data analysis on all 50 state health department responses to a question about their regulatory and legal authority to intervene or assist facilities without invitation when outbreaks are suspected (as determined by the health department) or high HAI rates have been identified (eg, based on NHSN data). Results: When an outbreak is identified, 31 health departments (62%) indicated that they have the authority to intervene without invitation from a facility and 8 (16%) did not specify. Among the 11 health departments (22%) that indicated that they do not have this authority, 5 (45%) states noted that they operate under decentralized systems in which the local health department can intervene in outbreak situations and the state health department is available to assist. When a health department identifies high HAI rates, 14 health departments (28%) indicated that they have the authority to intervene without invitation, 22 (44%) indicated that they do not, and 14 (28%) did not specify. Among those in the latter categories, 3 stated they can work through their local health departments, which do have this authority and 8 described working through partners (eg, State Hospital Association, n = 3 or State Healthcare Licensing Agency, n = 5). Discussion: Assistance from state health departments (eg, HAI/AR programs) in the context of outbreaks and high HAI rates has value that is usually well recognized and welcomed by healthcare facilities. Nonetheless, there are occasions when a health department might need to exert its authority to intervene. The preliminary analysis described here indicated that this authority was more commonly self-reported in the context of outbreaks than when high HAI rates are identified. These 2 situations are connected, as high rates might be indicative of unrecognized or unreported outbreak activity, and these issues may benefit from further analysis. Funding: None Disclosures: None

In the retina, several molecules involved in metabolism, the visual cycle, and other roles exhibit intrinsic fluorescence. The overall properties of retinal fluorescence depend on changes to the composition of these molecules and their environmental interactions due to transient functional shifts, especially in disease. This behooves the understanding of the origins and deviations of these properties within the multilayered retina at high lateral and axial resolution. Of particular interest is the fluorescence lifetime, a potential biomarker of function and disease independent of fluorescence intensity that can be measured in the retina with adaptive optics fluorescence lifetime ophthalmoscopy (AOFLIO). This work demonstrates the utility of the phasor method of analysis, an alternate approach to traditional multiexponential fitting, to evaluate photoreceptor two-photon excited AOFLIO data and separate them based on functional differences. Phasor analysis on fluorescence lifetime decay data allowed the repeatable segregation of S from M/L cones, likely from differences in functional or metabolic demands. Furthermore, it is possible to track the lifetime changes in S cones after photodamage. Phasor analysis increases the sensitivity of AOFLIO to functional differences between cells and has the potential to improve our understanding of pathways involved in normal and diseased conditions at the cellular scale throughout the retina.

Repetitive dynamic two-photon imaging of retinoid cycle fluorophores and subcellular details of their location within the retinal pigment epithelium in intact eyes of live mice. Two-photon excitation microscopy can image retinal molecular processes in vivo . Intrinsically fluorescent retinyl esters in subcellular structures called retinosomes are an integral part of the visual chromophore regeneration pathway. Fluorescent condensation products of all- trans -retinal accumulate in the eye with age and are also associated with age-related macular degeneration (AMD). Here, we report repetitive, dynamic imaging of these compounds in live mice through the pupil of the eye. By leveraging advanced adaptive optics, we developed a data acquisition algorithm that permitted the identification of retinosomes and condensation products in the retinal pigment epithelium by their characteristic localization, spectral properties and absence in genetically modified or drug-treated mice. This imaging approach has the potential to detect early molecular changes in retinoid metabolism that trigger light- and AMD-induced retinal defects and to assess the effectiveness of treatments for these conditions.

ObjectiveTo evaluate the benefits and risks of zinc formulations compared with controls for prevention or treatment of acute viral respiratory tract infections (RTIs) in adults.MethodSeventeen English and Chinese databases were searched in April/May 2020 for randomised controlled trials (RCTs), and from April/May 2020 to August 2020 for SARS-CoV-2 RCTs. Cochrane rapid review methods were applied. Quality appraisals used the Risk of Bias 2.0 and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.ResultsTwenty-eight RCTs with 5446 participants were identified. None were specific to SARS-CoV-2. Compared with placebo, oral or intranasal zinc prevented 5 RTIs per 100 person-months (95% CI 1 to 8, numbers needed to treat (NNT)=20, moderate-certainty/quality). Sublingual zinc did not prevent clinical colds following human rhinovirus inoculations (relative risk, RR 0.96, 95% CI 0.77 to 1.21, moderate-certainty/quality). On average, symptoms resolved 2 days earlier with sublingual or intranasal zinc compared with placebo (95% CI 0.61 to 3.50, very low-certainty/quality) and 19 more adults per 100 were likely to remain symptomatic on day 7 without zinc (95% CI 2 to 38, NNT=5, low-certainty/quality). There were clinically significant reductions in day 3 symptom severity scores (mean difference, MD −1.20 points, 95% CI −0.66 to −1.74, low-certainty/quality), but not average daily symptom severity scores (standardised MD −0.15, 95% CI −0.43 to 0.13, low-certainty/quality). Non-serious adverse events (AEs) (eg, nausea, mouth/nasal irritation) were higher (RR 1.41, 95% CI 1.17 to 1.69, NNHarm=7, moderate-certainty/quality). Compared with active controls, there were no differences in illness duration or AEs (low-certainty/quality). No serious AEs were reported in the 25 RCTs that monitored them (low-certainty/quality).ConclusionsIn adult populations unlikely to be zinc deficient, there was some evidence suggesting zinc might prevent RTIs symptoms and shorten duration. Non-serious AEs may limit tolerability for some. The comparative efficacy/effectiveness of different zinc formulations and doses were unclear. The GRADE-certainty/quality of the evidence was limited by a high risk of bias, small sample sizes and/or heterogeneity. Further research, including SARS-CoV-2 clinical trials is warranted.PROSPERO registration numberCRD42020182044.

BackgroundEach year, 220 000 episodes of self-harm are managed by emergency departments in England, providing support to people at risk of suicide.AimsTo explore treatment of self-harm in emergency departments, comparing perspectives of patients, carers and practitioners.MethodFocus groups and semi-structured interviews with 79 people explored experiences of receiving/delivering care. Participants were patients (7 young people, 12 adults), 8 carers, 15 generalist emergency department practitioners and 37 liaison psychiatry practitioners. Data were analysed using framework analysis.ResultsWe identified four themes. One was common across stakeholder groups: (a) the wider system is failing people who self-harm: they often only access crisis support as they are frequently excluded from services, leading to unhelpful cycles of attending the emergency department. Carers felt over-relied upon and ill-equipped to keep the person safe. Three themes reflected different perspectives across stakeholders: (b) practitioners feel powerless and become hardened towards patients, with patients feeling judged for seeking help which exacerbates their distress; (c) patients need a human connection to offer hope when life feels hopeless, yet practitioners underestimate the therapeutic potential of interactions; and (d) practitioners are fearful of blame if someone takes their life: formulaic question-and-answer risk assessments help make staff feel safer but patients feel this is not a valid way of assessing risk or addressing their needs.ConclusionsEmergency department practitioners should seek to build a human connection and validate patients’ distress, which offers hope when life feels hopeless. Patients consider this a therapeutic intervention in its own right. Investment in self-harm treatment is indicated.

We review the ecological rationale behind the potential compatibility between top predators and biodiversity conservation, and examine their effectiveness as surrogate species. Evidence suggests that top predators promote species richness or are spatio-temporally associated with it for six causative or noncausative reasons: resource facilitation, trophic cascades, dependence on ecosystem productivity, sensitivity to dysfunctions, selection of heterogeneous sites and links to multiple ecosystem components. Therefore, predator-centered conservation may deliver certain biodiversity goals. To this aim, predators have been employed in conservation as keystone, umbrella, sentinel, flagship, and indicator species. However, quantitative tests of their surrogate-efficacy have been astonishingly few. Evidence suggests they may function as structuring agents and biodiversity indicators in some ecosystems but not others, and that they perform poorly as umbrella species; more consensus exists for their efficacy as sentinel and flagship species. Conservation biologists need to use apex predators more cautiously, as part of wider, context-dependent mixed strategies.

Women are underrepresented at higher levels of promotion or leadership despite the increasing number of women physicians. In surgery, this has been compounded by historical underrepresentation. With a nation-wide focus on the importance of diversity, our aim was to provide a current snapshot of gender representation in Canadian universities. This cross-sectional online website review assessed the current faculty listings for 17 university-affiliated academic surgical training departments across Canada in the 2019/2020 academic year. Gender diversity of academic surgical faculty was assessed across surgical disciplines. Additionally, gender diversity in career advancement, as described by published leadership roles, promotion and faculty appointment, was analyzed. Women surgeons are underrepresented across Canadian surgical specialties (totals: 2,689 men versus 531 women). There are significant differences in the gender representation of surgeons between specialties and between universities, regardless of specialty. Women surgeons had a much lower likelihood of being at the highest levels of promotion (OR: 0.269, 95% CI: 0.179-0.405). Men surgeons were statistically more likely to hold academic leadership positions than women (p = 0.0002). Women surgeons had a much lower likelihood of being at the highest levels of leadership (OR: 0.372, 95% CI: 0.216-0.641). This study demonstrates that women surgeons are significantly underrepresented at the highest levels of academic promotion and leadership in Canada. Our findings allow for a direct comparison between Canadian surgical subspecialties and universities. Individual institutions can use these data to critically appraise diversity policies already in place, assess their workforce and apply a metric from which change can be measured.