Streptothricin F is a bactericidal antibiotic effective against highly drug-resistant gram-negative bacteria that interacts with the 30S subunit of the 70S ribosome.

The streptothricin natural product mixture (also known as nourseothricin) was discovered in the early 1940s, generating intense initial interest because of excellent gram-negative activity. Here, we establish the activity spectrum of nourseothricin and its main components, streptothricin F (S-F, 1 lysine) and streptothricin D (S-D, 3 lysines), purified to homogeneity, against highly drug-resistant, carbapenem-resistant Enterobacterales (CRE) and Acinetobacter baumannii. For CRE, the MIC50 and MIC90 for S-F and S-D were 2 and 4 µM, and 0.25 and 0.5 µM, respectively. S-F and nourseothricin showed rapid, bactericidal activity. S-F and S-D both showed approximately 40-fold greater selectivity for prokaryotic than eukaryotic ribosomes in in vitro translation assays. In vivo, delayed renal toxicity occurred at >10-fold higher doses of S-F compared with S-D. Substantial treatment effect of S-F in the murine thigh model was observed against the otherwise pandrug-resistant, NDM-1-expressing Klebsiella pneumoniae Nevada strain with minimal or no toxicity. Cryo-EM characterization of S-F bound to the A. baumannii 70S ribosome defines extensive hydrogen bonding of the S-F steptolidine moiety, as a guanine mimetic, to the 16S rRNA C1054 nucleobase (Escherichia coli numbering) in helix 34, and the carbamoylated gulosamine moiety of S-F with A1196, explaining the high-level resistance conferred by corresponding mutations at the residues identified in single rrn operon E. coli. Structural analysis suggests that S-F probes the A-decoding site, which potentially may account for its miscoding activity. Based on unique and promising activity, we suggest that the streptothricin scaffold deserves further preclinical exploration as a potential therapeutic for drug-resistant, gram-negative pathogens.

High-Resolution Structural Proteomics of Mitochondria Using the 'Build and Retrieve' Methodology.

The application of integrated systems biology to the field of structural biology is a promising new direction, although it is still in the infant stages of development. Here we report the use of single particle cryo-EM to identify multiple proteins from three enriched heterogeneous fractions prepared from human liver mitochondrial lysate. We simultaneously identify and solve high-resolution structures of nine essential mitochondrial enzymes with key metabolic functions, including fatty acid catabolism, reactive oxidative species clearance, and amino acid metabolism. Our methodology also identified multiple distinct members of the acyl-CoA dehydrogenase family. This work highlights the potential of cryo-EM to explore tissue proteomics at the atomic level.

A 'Build and Retrieve' methodology to simultaneously solve cryo-EM structures of membrane proteins.

Single-particle cryo-electron microscopy (cryo-EM) has become a powerful technique in the field of structural biology. However, the inability to reliably produce pure, homogeneous membrane protein samples hampers the progress of their structural determination. Here, we develop a bottom-up iterative method, Build and Retrieve (BaR), that enables the identification and determination of cryo-EM structures of a variety of inner and outer membrane proteins, including membrane protein complexes of different sizes and dimensions, from a heterogeneous, impure protein sample. We also use the BaR methodology to elucidate structural information from Escherichia coli K12 crude membrane and raw lysate. The findings demonstrate that it is possible to solve high-resolution structures of a number of relatively small (<100 kDa) and less abundant (<10%) unidentified membrane proteins within a single, heterogeneous sample. Importantly, these results highlight the potential of cryo-EM for systems structural proteomics.

Structures of the mycobacterial membrane protein MmpL3 reveal its mechanism of lipid transport.

The mycobacterial membrane protein large 3 (MmpL3) transporter is essential and required for shuttling the lipid trehalose monomycolate (TMM), a precursor of mycolic acid (MA)-containing trehalose dimycolate (TDM) and mycolyl arabinogalactan peptidoglycan (mAGP), in Mycobacterium species, including Mycobacterium tuberculosis and Mycobacterium smegmatis. However, the mechanism that MmpL3 uses to facilitate the transport of fatty acids and lipidic elements to the mycobacterial cell wall remains elusive. Here, we report 7 structures of the M. smegmatis MmpL3 transporter in its unbound state and in complex with trehalose 6-decanoate (T6D) or TMM using single-particle cryo-electron microscopy (cryo-EM) and X-ray crystallography. Combined with calculated results from molecular dynamics (MD) and target MD simulations, we reveal a lipid transport mechanism that involves a coupled movement of the periplasmic domain and transmembrane helices of the MmpL3 transporter that facilitates the shuttling of lipids to the mycobacterial cell wall.

Site-Specific knockdown of microglia in the locus coeruleus regulates hypervigilant responses to social stress in female rats.

BACKGROUND: Women are at increased risk for psychosocial stress-related anxiety disorders, yet mechanisms regulating this risk are unknown. Psychosocial stressors activate microglia, and the resulting neuroimmune responses that females exhibit heightened sensitivity to may serve as an etiological factor in their elevated risk. However, studies examining the role of microglia during stress in females are lacking. METHODS: Microglia were manipulated in the stress-sensitive locus coeruleus (LC) of female rats in the context of social stress in two ways. First, intra-LC lipopolysaccharide (LPS; 0 or 3 µg/side, n = 5-6/group), a potent TLR4 agonist and microglial activator, was administered. One hour later, rats were exposed to control or an aggressive social defeat encounter between two males (WS, 15-min). In a separate study, females were treated with intra-LC or intra-central amygdala mannosylated liposomes containing clodronate (m-CLD; 0 or 25 µg/side, n = 13-14/group), a compound toxic to microglia. WS-evoked burying, cardiovascular responses, and sucrose preference were measured. Brain and plasma cytokines were quantified, and cardiovascular telemetry assessed autonomic balance. RESULTS: Intra-LC LPS augmented the WS-induced burying response and increased plasma corticosterone and interleukin-1ß (IL-1ß). Further, the efficacy and selectivity of microinjected m-CLD was fully characterized. In the context of WS, intra-LC m-CLD attenuated the hypervigilant burying response during WS as well as the accumulation of intra-LC IL-1ß. Intra-central amygdala m-CLD had no effect on WS-evoked behavior. CONCLUSIONS: These studies highlight an innovative method for depleting microglia in a brain region specific manner and indicate that microglia in the LC differentially regulate hypervigilant WS-evoked behavioral and autonomic responses.

Structural and Functional Diversity of Resistance-Nodulation-Cell Division Transporters.

Multidrug resistant (MDR) bacteria are a global threat with many common infections becoming increasingly difficult to eliminate. While significant effort has gone into the development of potent biocides, the effectiveness of many first-line antibiotics has been diminished due to adaptive resistance mechanisms. Bacterial membrane proteins belonging to the resistance-nodulation-cell division (RND) superfamily play significant roles in mediating bacterial resistance to antimicrobials. They participate in multidrug efflux and cell wall biogenesis to transform bacterial pathogens into "superbugs" that are resistant even to last resort antibiotics. In this review, we summarize the RND superfamily of efflux transporters with a primary focus on the assembly and function of the inner membrane pumps. These pumps are critical for extrusion of antibiotics from the cell as well as the transport of lipid moieties to the outer membrane to establish membrane rigidity and stability. We analyze recently solved structures of bacterial inner membrane efflux pumps as to how they bind and transport their substrates. Our cumulative data indicate that these RND membrane proteins are able to utilize different oligomerization states to achieve particular activities, including forming MDR pumps and cell wall remodeling machineries, to ensure bacterial survival. This mechanistic insight, combined with simulated docking techniques, allows for the design and optimization of new efflux pump inhibitors to more effectively treat infections that today are difficult or impossible to cure.

Low knowledge of newborn danger signs among pregnant women in Papua New Guinea and implications for health seeking behaviour in early infancy - findings from a longitudinal study.

BACKGROUND: Globally, 2.5 million babies die in the first 28 days of life each year with most of these deaths occurring in low- and middle-income countries. Early recognition of newborn danger signs is important in prompting timely care seeking behaviour. Little is known about women's knowledge of newborn danger signs in Papua New Guinea. This study aims to assess this knowledge gap among a cohort of women in East New Britain Province. METHODS: This study assessed knowledge of newborn danger signs (as defined by the World Health Organization) at three time points from a prospective cohort study of women in East New Britain Province, factors associated with knowledge of danger signs after childbirth were assessed using logistic regression. This study includes quantitative and qualitative interview data from 699 pregnant women enrolled at their first antenatal clinic visit, followed up after childbirth (n = 638) and again at one-month post-partum (n = 599). RESULTS: Knowledge of newborn danger signs was very low. Among the 638 women, only 9.4% knew three newborn danger signs after childbirth and only one knew all four essential danger signs defined by Johns Hopkins University 'Birth Preparedness and Complication Readiness' Index. Higher knowledge scores were associated with higher gravidity, income level, partner involvement in antenatal care, and education. CONCLUSION: Low levels of knowledge of newborn danger signs among pregnant women are a potential obstacle to timely care-seeking in rural Papua New Guinea. Antenatal and postnatal education, and policies that support enhanced education and decision-making powers for women and their families, are urgently needed.

Community perspectives and experiences of quality maternal and newborn care in East New Britain, Papua New Guinea.

BACKGROUND: Quality maternal and newborn care is essential for improving the health of mothers and babies. Low- and middle-income countries, such as Papua New Guinea (PNG), face many barriers to achieving quality care for all. Efforts to improve the quality of maternal and newborn care must involve community in the design, implementation, and evaluation of initiatives to ensure that interventions are appropriate and relevant for the target community. We aimed to describe community members' perspectives and experiences of maternal and newborn care, and their ideas for improvement in one province, East New Britain, in PNG. METHODS: We undertook a qualitative descriptive study in partnership with and alongside five local health facilities, health care workers and community members, using a Partnership Defined Quality Approach. We conducted ten focus group discussions with 68 community members (identified through church, market and other community-based groups) in East New Britain PNG to explore perspectives and experiences of maternal and newborn care, identify enablers and barriers to quality care and interventions to improve care. Discussions were transcribed verbatim. A mixed inductive and deductive analysis was conducted including application of the World Health Organisation (WHO) Quality Maternal and Newborn Care framework. RESULTS: Using the WHO framework, we present the findings in accordance with the five experience of care domains. We found that the community reported multiple challenges in accessing care and facilities were described as under-staffed and under resourced. Community members emphasised the importance of good communication and competent, caring and respectful healthcare workers. Both women and men expressed a strong desire for companionship during labor and birth. Several changes were suggested by the community that could immediately improve the quality of care. CONCLUSIONS: Community perspectives and experiences are critical for informing effective and sustainable interventions to improve the quality of maternal and newborn care and increasing facility-based births in PNG. A greater understanding of the care experience as a key component of quality care is needed and any quality improvement initiatives must include the user experience as a key outcome measure.

Improving the care provided to, and experienced by, women and their families during pregnancy and childbirth is important for improving the health of mothers and babies. Community members should be involved in thinking about appropriate ways to improve care. Papua New Guinea (PNG) is a country in the Pacific which faces multiple challenges to improving care during pregnancy and birth. We aimed to understand what community members think about care provided and experienced during labour and birth in East New Britain, a rural province of PNG. We worked with five health facilities, health workers and community members in East New Britain to develop a qualitative research project. We carried out 10 focus group discussions with community members in East New Britain to understand what the provision and experience of care was like during labour and birth, and ways that it could be improved. We found that community members identified multiple challenges in getting to facilities and many facilities were found to have not enough supplies, equipment, or staff. Community members wanted staff that were good at their work but also caring and respectful. Women wanted to have support people present during labour and birth and many men wanted to be present too. Our results show that it is important to understand what the community thinks about the quality of care during labour and birth and this information is helpful to design effective activities to improve the care provided and experienced.

Controlled temperature chain for vaccination in low- and middle-income countries: a realist evidence synthesis.

Objective: To evaluate the evidence describing how the controlled temperature chain approach for vaccination could lead to improved equitable immunization coverage in low- and middle-income countries. Methods: We created a theory of change construct from the Controlled temperature chain: strategic roadmap for priority vaccines 2017-2020, containing four domains: (i) uptake and demand for the approach; (ii) compliance and safe use of the approach; (iii) programmatic efficiency gains from the approach; and (iv) improved equitable immunization coverage. To verify and improve the theory of change, we applied a realist review method to analyse published descriptions of controlled temperature chain or closely related experiences. Findings: We evaluated 34 articles, describing 22 unique controlled temperature chain or closely related experiences across four World Health Organization regions. We identified a strong demand for this approach among service delivery providers; however, generating an equal level of demand among policy-makers requires greater evidence on economic benefits and on vaccination coverage gains, and use case definitions. Consistent evidence supported safety of the approach when integrated into special vaccination programmes. Feasible training and supervision supported providers in complying with protocols. Time-savings were the main evidence for efficiency gains, while cost-saving data were minimal. Improved equitable coverage was reported where vaccine storage beyond the cold chain enabled access to hard-to-reach populations. No evidence indicated an inferior vaccine effectiveness nor increased adverse event rates for vaccines delivered under the approach. Conclusion: Synthesized evidence broadly supported the initial theory of change. Addressing evidence gaps on economic benefits and coverage gains may increase future uptake.

Epidemiology of prurigo nodularis in England: a retrospective database analysis.

BACKGROUND: Prurigo nodularis is a debilitating skin condition that is classified as rare by the Genetic and Rare Diseases Information Center (GARD) and the National Organization for Rare Diseases (NORD). There are currently no estimates of the prevalence of prurigo nodularis in England. OBJECTIVES: We aimed to address this data gap by describing the epidemiology of prurigo nodularis in a representative dataset derived from the English National Health Service. METHODS: The study utilized data from the Clinical Practice Research Datalink linked to Hospital Episode Statistics inpatient data. Patients with a diagnosis of prurigo nodularis were selected by clinical code in the primary care or inpatient datasets. Case definition was based on a minimum of two distinct diagnoses to maximize specificity. Point prevalence was calculated for the midpoint of 2018 and incidence rates from 2008 to 2018 were presented. For those classified as incident cases, demographic and clinical characteristics were reported. In sensitivity analyses the case definition was modified to relax the multiple diagnosis criteria and to restrict cases to those diagnosed within a maximum of 4 or 10 years of the midpoint prevalence date. RESULTS: Overall, 11 656 patients within the dataset had at least one prurigo nodularis diagnosis. Following application of the relevant inclusion criteria, 2743 patients formed the point prevalent cohort; the estimated prevalence was 3·27 patients per 10 000 population [95% confidence interval (CI) 3·15-3·40]. In sensitivity analyses the estimated prevalence ranged from 2·24 (95% CI 2·14-2·34) to 6·98 (95% CI 6·80-7·16). Incidence over the study period was 2·88 per 100 000 patient-years. Comorbidity was relatively high in this population, notably for atopic dermatitis (52·2%), depression (41·1%) and anxiety (35·4%). CONCLUSIONS: This study supports the NORD/GARD classification of prurigo nodularis as a rare disease with a prevalence of 3·27 patients per 10 000 population, which equates to 18 471 patients living with the disease in England in 2018. The relatively high prevalence of comorbidity observed for these patients may increase the complexity of management.

Quality newborn care in East New Britain, Papua New Guinea: measuring early newborn care practices and identifying opportunities for improvement.

BACKGROUND: Renewed attention and investment is needed to improve the quality of care during the early newborn period to address preventable newborn deaths and stillbirths in Papua New Guinea (PNG). We aimed to assess early newborn care practices and identify opportunities for improvement in one province (East New Britain) in PNG. METHODS: A mixed-methods study was undertaken in five rural health facilities in the province using a combination of facility audits, labour observations and qualitative interviews with women and maternity providers. Data collection took place between September 2019 and February 2020. Quantitative data were analysed descriptively, whilst qualitative data were analysed using content analysis. Data were triangulated by data source. RESULTS: Five facility audits, 30 labour observations (in four of the facilities), and interviews with 13 women and eight health providers were conducted to examine early newborn care practices. We found a perinatal mortality rate of 32.2 perinatal deaths per 1000 total births and several barriers to quality newborn care, including an insufficient workforce, critical infrastructure and utility constraints, and limited availability of essential newborn medicines and equipment. Most newborns received at least one essential newborn care practice in the first hour of life, such as immediate and thorough drying (97%). CONCLUSIONS: We observed high rates of essential newborn care practices including immediate skin-to-skin and delayed cord clamping. We also identified multiple barriers to improving the quality of newborn care in East New Britain, PNG. These findings can inform the development of effective interventions to improve the quality of newborn care. Further, this study demonstrates that multi-faceted programs that include increased investment in the health workforce, education and training, and availability of essential equipment, medicines, and supplies are required to improve newborn outcomes.

Designing a Pro-Equity HPV Vaccine Delivery Program for Girls Who Have Dropped Out of School: Community Perspectives From Uttar Pradesh, India.

India experiences a substantial burden of cervical cancer and accounts for nearly one third of cervical cancer deaths worldwide. While human papillomavirus (HPV) vaccines have been introduced subnationally in some states, HPV has not yet been rolled out nationally. Given the target age group, schools are the most common delivery channel for HPV vaccines, but this fails to account for local girls who never attended or no longer attend school. We conducted a qualitative, design-informed, community-based study conducted in Uttar Pradesh, India. We assessed facilitators and barriers among out-of-school girls and proposed program characteristics to inform the design of pro-equity HPV vaccine delivery programs for out-of-school girls. Programs should improve parental knowledge of the risk of cervical cancer, engage vaccinated girls as vaccine champions, utilize varied media options for low-literacy populations, and ensure that HPV vaccine services are accessible and flexible to accommodate out-of-school girls. In areas with poor or irregular school attendance among adolescent girls, HPV vaccine coverage will remain suboptimal until programs can effectively address their needs and reach this priority population. Our findings present a meaningful opportunity for program planners to purposefully design HPV vaccination programs according to these parameters, rather than modifying existing programs to include HPV vaccine. Adolescent girls, their parents, and other community members should be involved in program design to ensure that the program can effectively meet the needs of adolescent girls who are not in school.

Mycoplasma genitalium and Other Reproductive Tract Infections in Pregnant Women, Papua New Guinea, 2015-2017.

Much about the range of pathogens, frequency of coinfection, and clinical effects of reproductive tract infections (RTIs) among pregnant women remains unknown. We report on RTIs (Mycoplasma genitalium, Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, Treponema pallidum subspecies pallidum, bacterial vaginosis, and vulvovaginal candidiasis) and other reproductive health indicators in 699 pregnant women in Papua New Guinea during 2015-2017. We found M. genitalium, an emerging pathogen in Papua New Guinea, in 12.5% of participants. These infections showed no evidence of macrolide resistance. In total, 74.1% of pregnant women had >1 RTI; most of these infections were treatable. We detected sexually transmitted infections (excluding syphilis) in 37.7% of women. Our findings showed that syndromic management of infections is greatly inadequate. In total, 98.4% of women had never used barrier contraception. These findings will inform efforts to improve reproductive healthcare in Papua New Guinea.

Ending malnutrition in all its forms requires scaling up proven nutrition interventions and much more: a 129-country analysis.

BACKGROUND: Sustainable Development Goal (SDG) 2.2 calls for an end to all forms of malnutrition, with 2025 targets of a 40% reduction in stunting (relative to 2012), for wasting to occur in less than 5% of children, and for a 50% reduction in anaemia in women (15-49 years). We assessed the likelihood of countries reaching these targets by scaling up proven interventions and identified priority interventions, based on cost-effectiveness. METHODS: For 129 countries, the Optima Nutrition model was used to compare 2019-2030 nutrition outcomes between a status quo (maintained intervention coverage) scenario and a scenario where outcome-specific interventions were scaled up to 95% coverage over 5 years. The average cost-effectiveness of each intervention was calculated as it was added to an expanding package of interventions. RESULTS: Of the 129 countries modelled, 46 (36%), 66 (51%) and 0 (0%) were on track to achieve the stunting, wasting and anaemia targets respectively. Scaling up 18 nutrition interventions increased the number of countries reaching the SDG 2.2 targets to 50 (39%), 83 (64%) and 7 (5%) respectively. Intermittent preventative treatment of malaria during pregnancy (IPTp), infant and young child feeding education, vitamin A supplementation and lipid-based nutrition supplements for children produced 88% of the total impact on stunting, with average costs per case averted of US$103, US$267, US$556 and US$1795 when interventions were consecutively scaled up, respectively. Vitamin A supplementation and cash transfers produced 100% of the total global impact on prevention of wasting, with average costs per case averted of US$1989 and US$19,427, respectively. IPTp, iron and folic acid supplementation for non-pregnant women, and multiple micronutrient supplementation for pregnant women produced 85% of the total impact on anaemia prevalence, with average costs per case averted of US$9, US$35 and US$47, respectively. CONCLUSIONS: Prioritising nutrition investment to the most cost-effective interventions within the country context can maximise the impact of funding. A greater focus on complementing nutrition-specific interventions with nutrition-sensitive ones that address the social determinants of health is critical to reach the SDG targets.

Healthcare utilization and associated costs following initiation of perampanel in patients with epilepsy.

PURPOSE: We compared health service utilization and costs for patients with epilepsy before and after initiation of perampanel and compared with matched controls. METHOD: Patients were selected from the Clinical Practice Research Datalink (CPRD). Patients initiating perampanel were matched to controls initiating an alternate add-on therapy for the same underlying epilepsy subtype. First prescription defined index date. Primary and secondary care contacts and associated costs were aggregated in the 12 months before and after index date. Secondary care contacts were available for a subset (~60%) of patients. RESULTS: Three hundred and forty-three patients treated with perampanel were identified. One hundred and eighty-three (53.4%) were male, mean age was 39.1 (sd: 16.0). Mean epilepsy duration was 21.1 (standard deviation (sd): 13.3) years. Two hundred and eighty-seven (83.7%) were matched to controls. Inpatient admissions with a primary diagnosis of epilepsy (0.5 versus 0.2 per patient-year (ppy), p = 0.002) and neurology specific outpatient appointments (3.2 versus 2.9 ppy, p = 0.041) were significantly reduced following initiation with perampanel. Total costs attributable to epilepsy (£1889 to 1477 ppy) and overall secondary costs (£2593 to £2102) were also significantly reduced. There was no significant difference in primary care, outpatient, or general inpatient admissions. Compared with controls, there was a significant reduction in primary epilepsy admissions (incidence rate ratio (IRR): 0.423; 95% Confidence intervals (CI): 0.198-0.835) but a significant increase in outpatient appointments (1.306; 95% CI: 1.154-1.478) and accident and emergency contacts (1.603; 95% CI: 1.081-2.390) for patients treated with perampanel. CONCLUSION: Treatment with perampanel is associated with reduced epilepsy-related inpatient admissions and accident and emergency contacts.

Strengthening routine immunization in Papua New Guinea: a cross-sectional provincial assessment of front-line services.

BACKGROUND: Routine immunization programs face many challenges in settings such as Papua New Guinea with dispersed rural populations, rugged geography and limited resources for transport and health. Low routine coverage contributes to disease outbreaks such as measles and the polio that re-appeared in 2018. We report on an in-depth local assessment that aimed to document immunization service provision so as to review a new national strategy, and consider how routine immunization could be better strengthened. METHODS: In East New Britain Province, over 2016 and 17, we carried out a cross-sectional assessment of 12 rural health facilities, staff and clients. The study was timed to follow implementation of a new national strategy for strengthening routine immunization. We used interview, structured observation, and records review, informed by theory-based evaluation, a World Health Organization quality checklist, and other health services research tools. RESULTS: We documented strengths and weaknesses across six categories of program performance relevant to national immunization strategy and global standards. We found an immunization service with an operational level of staff, equipment and procedures in place; but one that could reach only half to two thirds of its target population. Stronger routine services require improvement in: understanding of population catchments, tracking the unvaccinated, reach and efficiency of outreach visits, staff knowledge of vaccination at birth and beyond the first year of life, handling of multi-dose vials, and engagement of community members. Many local suggestions to enhance national plans, included more reliable on-demand services, integration of other family health services and increased involvement of men. CONCLUSIONS: The national strategy addresses most local gaps, but implementation and resourcing requires greater commitment. Long-term strengthening requires a major increase in centrally-allocated resources, however there are immediate locally feasible steps within current resources that could boost coverage and quality of routine immunization especially through better population-based local planning, and stronger community engagement. Our results also suggest areas where vaccination campaigns in PNG can contribute to routine immunization services.

Rules of RNA specificity of hnRNP A1 revealed by global and quantitative analysis of its affinity distribution.

Heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) is a multipurpose RNA-binding protein (RBP) involved in normal and pathological RNA metabolism. Transcriptome-wide mapping and in vitro evolution identify consensus hnRNP A1 binding motifs; however, such data do not reveal how surrounding RNA sequence and structural context modulate affinity. We determined the affinity of hnRNP A1 for all possible sequence variants (n = 16,384) of the HIV exon splicing silencer 3 (ESS3) 7-nt apical loop. Analysis of the affinity distribution identifies the optimal motif 5'-YAG-3' and shows how its copy number, position in the loop, and loop structure modulate affinity. For a subset of ESS3 variants, we show that specificity is determined by association rate constants and that variants lacking the minimal sequence motif bind competitively with consensus RNA. Thus, the results reveal general rules of specificity of hnRNP A1 and provide a quantitative framework for understanding how it discriminates between alternative competing RNA ligands in vivo.

Helmet CPAP revisited in COVID-19 pneumonia: A case series.

INTRODUCTION: Noninvasive positive pressure ventilation (NIPPV) plays an important role in the management of respiratory failure. However, since the emergence of the COVID-19 pandemic, utilization of traditional face mask NIPPV has been curtailed in part due to risk of aerosolization of respiratory particles and subsequent health care worker exposure. A randomized clinical trial in 2016 reported that an alternative interface, helmet NIPPV, may be more effective than traditional NIPPV at preventing intubation and improving mortality. The helmet NIPPV interface provides positive airway pressure, while also theoretically minimizing aerosolization, making it a feasible modality in management of respiratory failure in COVID-19 patients. CASE AND OUTCOMES: This report describes a single-center experience of a series of three COVID-19 patients with hypoxemic respiratory failure managed with helmet NIPPV. One patient was able to avoid intubation while a second patient was successfully extubated to NIPPV. Ultimately, the third patient was unable to avoid intubation with helmet NIPPV, although the application of the device was late in the progression of the disease. DISCUSSION: NIPPV is an important modality in the management of respiratory failure and has been shown to reduce the need for immediate endotracheal intubation in select populations. For patients unable to tolerate facemask NIPPV, the helmet provides an alternate interface. In COVID-19 patients, the helmet interface may reduce the risk of virus exposure to health care workers from aerosolization. Based on this experience, we recommend that helmet NIPPV can be considered as a feasible option for the management of patients with COVID-19, whether the goal is to prevent immediate intubation or avoid post-extubation respiratory failure. Randomized studies are needed to definitively validate the use of helmet NIPPV in this population. CONCLUSION: Helmet NIPPV is a feasible therapy to manage COVID-19 patients.

Evaluation of exacerbations and blood eosinophils in UK and US COPD populations.

BACKGROUND: Blood eosinophil counts and history of exacerbations have been proposed as predictors of patients with chronic obstructive pulmonary disease (COPD) who may benefit from triple therapy (inhaled corticosteroid, long-acting ß2-agonist and long-acting muscarinic antagonist). METHODS: In a retrospective cohort analysis we examined the profiles of COPD patients from the UK Clinical Practice Research Datalink (CPRD) and US Optum Clinformatics™ Data Mart (Optum) databases with reference to exacerbation frequency and blood eosinophil distribution. RESULTS: Of the 31,437 (CPRD) and 383,825 (Optum) patients with COPD, 15,364 (CPRD) and 139,465 (Optum) met the eligibility criteria and were included. Among patients with ≥2 exacerbations and available eosinophil counts in the baseline period (CPRD, n = 3089 and Optum, n = 13414), 17.0 and 13.3% respectively had eosinophil counts ≥400 cells/µL. Patients with ≥2 exacerbations or eosinophil count ≥400 cells/µL during first year, exacerbated at least once (CPRD, 82.8% vs Optum, 80.6%) or continued to have eosinophil count ≥300 cells/µL (76.8% vs 76.5%), respectively in the follow-up year. In both years, a higher variability in the number of exacerbations and eosinophil count was observed in patients with one exacerbation and eosinophil counts between 300 and 400 cells/µL; patients with eosinophil count < 150 cells/µL had the lowest variability. Approximately 10% patients had both ≥2 exacerbations and eosinophil count ≥300 cells/µL across the databases. CONCLUSION: A high variability in blood eosinophil counts over two consecutive years was observed in UK and US patients with COPD and should be considered while making treatment decisions. A small proportion of COPD patients had frequent exacerbations and eosinophil count ≥300 cells/µL.

Multiple morbidities in pregnancy: Time for research, innovation, and action.

In a Guest Editorial, James Beeson and colleagues discuss the contribution of nonobstetric morbidity to mortality during and around pregnancy and what needs to be done to address this global health challenge.