Distant relatives of a eukaryotic cell-specific toxin family evolved a complement-like mechanism to kill bacteria.

Cholesterol-dependent cytolysins (CDCs) comprise a large family of pore-forming toxins produced by Gram-positive bacteria, which are used to attack eukaryotic cells. Here, we functionally characterize a family of 2-component CDC-like (CDCL) toxins produced by the Gram-negative Bacteroidota that form pores by a mechanism only described for the mammalian complement membrane attack complex (MAC). We further show that the Bacteroides CDCLs are not eukaryotic cell toxins like the CDCs, but instead bind to and are proteolytically activated on the surface of closely related species, resulting in pore formation and cell death. The CDCL-producing Bacteroides is protected from the effects of its own CDCL by the presence of a surface lipoprotein that blocks CDCL pore formation. These studies suggest a prevalent mode of bacterial antagonism by a family of two-component CDCLs that function like mammalian MAC and that are wide-spread in the gut microbiota of diverse human populations.

Smartphone use for Paediatric Calculations in Emergencies (SPaCE).

BACKGROUND: The preparation for critically ill children involves calculating drug and fluid volumes using the commonly taught WETFLAG (weight, energy, endotracheal tube, fluids, lorazepam, adrenaline, glucose) acronym. While smartphone applications (apps) are increasingly used for these calculations in clinical practice, limited studies have explored their accuracy and safety. AIM: To assess the accuracy of three calculation methods for paediatric emergency drug doses and fluid volumes: a smartphone app, reference charts and traditional calculation methods. The secondary aims were to investigate the effect on the time taken and self-reported stress levels. METHODS: A convenience sample of healthcare professionals from four hospitals contributed. Participants calculated drug and fluid doses for fictional patients using the three different methods. The method and case order were randomised centrally. The study recorded the number of errors made during the calculations, healthcare professionals' self-reported stress levels on a scale of 0 (no stress) to 10 (maximum stress) and the time taken for each case. The app was developed at the direct request of the study team. RESULTS: Ninety-six participants calculated values for six fictional cases, resulting in 576 calculations. Traditional calculation methods showed a statistically significant higher rate of error compared with the use of a smartphone app or reference charts (mean=1, 0, 0, respectively). The smartphone app outperformed both traditional calculation methods and reference charts for time taken and user-reported stress levels. CONCLUSIONS: Traditional methods of 'WETFLAG' drug and fluid calculations are associated with a statistically significant increased risk of error compared with the use of reference charts or smartphone app. The smartphone app proved significantly faster and less stressful to use compared with traditional calculation methods or reference charts.

Fifteen-minute consultation: Rectal bleeding in children.

Bleeding per rectum in children is an infrequent presentation associated with a wide range of differential diagnoses, from benign to life-threatening. Irrespective of the underlying aetiology, it is typically a worrisome symptom for caregivers. Published data are limited, particularly for the UK population, from which to provide clear evidence-based guidance for assessment and management of infants, children and young people presenting with bleeding per rectum. In this Fifteen-Minute Consultation, we therefore explore the common aetiologies and combine opinions from acute paediatrics, paediatric gastroenterology and paediatric surgery to offer a structure for a diagnostic approach and initial management of lower gastrointestinal bleeding in infants, children and young people.

Identification of sepsis in paediatric emergency departments: A scoping review.

AIM: Sepsis is an acute illness associated with significant morbidity and mortality. Early detection and time-sensitive management of sepsis has been shown to improve outcomes. We report the results of a scoping review to explore methods evaluated for the identification of sepsis in children presenting to emergency departments. METHODS: A systematic literature search was carried out on two databases, Medline and Web of Science, to identify relevant studies published from 1990 to 2022. Data were extracted for age groups including study design, reference standard used for comparison, sepsis identification method evaluated and study quality. RESULTS: A total of 89 studies were identified from the literature search. There was significant heterogeneity in the age groups including study design and reference standards used for evaluating the performance of the sepsis identification methods. There has been a substantial increase in the number of published studies in the last 2 years. CONCLUSION: Our scoping review identifies marked heterogeneity in approaches to identifying sepsis but demonstrates a recent focus of research on patient outcomes. Using appropriate core outcome sets, developing reference standards, monitoring sepsis prevalence via registries and continuously monitoring process measures will provide robust evidence to identify the best performing identification tools and the impact they have on patient-orientated outcomes.

A proteolytically activated antimicrobial toxin encoded on a mobile plasmid of Bacteroidales induces a protective response.

Phocaeicola vulgatus is one of the most abundant and ubiquitous bacterial species of the human gut microbiota, yet a comprehensive analysis of antibacterial toxin production by members of this species has not been reported. Here, we identify and characterize a previously undescribed antibacterial protein. This toxin, designated BcpT, is encoded on a small mobile plasmid that is largely confined to strains of the closely related species Phocaeicola vulgatus and Phocaeicola dorei. BcpT is unusual in that it requires cleavage at two distinct sites for activation, and we identify bacterial proteases that perform this activation. We further identify BcpT's receptor as the Lipid A-core glycan, allowing BcpT to target species of other Bacteroidales families. Exposure of cells to BcpT induces a response involving an unusual sigma/anti-sigma factor pair that is likely triggered by cell envelope stress, resulting in the expression of genes that partially protect cells from multiple antimicrobial toxins.

Periorbital and orbital cellulitis in children: a survey of emergency physicians and analysis of clinical practice guidelines across the PERUKI network.

BACKGROUND: Due to limited evidence to guide management of periorbital cellulitis (POC), we surveyed current practice and assessed quality and consistency of local clinical practice guidelines (CPGs) to highlight future research priorities. METHODS: A web-based survey was sent to a designated emergency physician (who clinically assesses children) at Paediatric Emergency Research United Kingdom and Ireland (PERUKI) sites between 23 November 2018 to 22 January 2019. A nominated site lead offered one response as a department-wide perspective on admission, severity assessment, treatment, disposition and specialty consultation request. Sites shared their CPG. These were compared using a standardised data collection tool, and quality assessed using Standardised Reporting Practice Guidelines in Healthcare (RIGHT) criteria. Survey responses were also compared against CPG recommendations. RESULTS: 83% (49/59) institutions invited submitted an individual survey response. 67% of responding sites had a CPG and 63% (31/49) submitted these. CPG quality was poor (mean 6.7/35 RIGHT criteria). 21 different severity markers were identified across CPGs. Most CPGS recommend investigations for severe disease, yet 23% (7/31) advise blood culture universally. 90% of CPGs advise discharge with oral antibiotics for milder cases, yet 86% of respondents reported departmental admission of all patients with POC. Nearly all respondents included proptosis, systemically unwell and visual disturbance as indications for admission but differed regarding importance of other signs. CONCLUSIONS: We demonstrated variation in practice across the PERUKI network in assessment of severity and management of POC. CPGs vary in recommendations, and clinical practice appears to differ from CPGs. Guidelines were generally of poor quality when compared against RIGHT standards.

'Granulomatosis with polyangiitis after Pfizer vaccination': a case report.

The advent of COVID-19, caused by the SARS-CoV-2 virus, has resulted in over 541 million cases with 6.32 million deaths worldwide as of June 2022. The devastating consequences of this global pandemic resulted in the expedited generation of mRNA-based vaccines such as the Pfizer-BioNTech and Moderna vaccines. Although the vaccines have been effective, with recent data indicating greater than 95% effectiveness, rare complications have been reported, including manifestations of autoimmune phenomena. Herein, we report a rare case of Granulomatosis with polyangiitis (GPA) in an active duty military male soon after receiving the first dose of the Pfizer-BioNTech COVID-19 vaccine.

A 27-year-old active duty marine was admitted to our hospital after being transferred from Hawaii with concern of new autoimmune disease after receiving the Pfizer vaccine. The patient initially presented to the emergency department with joint pain, fever, chest pain, hemoptysis, and a nose bleed. A comprehensive workup demonstrated elevated inflammatory markers, progressive renal dysfunction, and a positive antibody panel consistent with antineutrophil cytoplasmic antibodies (ANCA) vasculitis. Due to the limited capabilities in his deployed setting, he was transferred to our hospital for a higher level of care. We performed some additional tests to include computed tomography (CT) imaging of his lungs and a renal biopsy which came back consistent with GPA. The patient was started on high-dose prednisone and rituximab, and he achieved remission. He was discharged from the hospital with follow-up arranged with rheumatology and nephrology. He remained in remission on follow-up.

Fifteen-minute consultation: How to manage eczema in children.

Atopic eczema is common and has a major impact on quality of life. Paediatricians and general practitioners play a key role in the non-specialist treatment of atopic eczema. However, the clinical nature of the diagnosis, multitude of topical therapies and sometimes complicated treatment strategies can leave both clinicians and families feeling bewildered. This article aims to provide a concise, patient-focused summary of the assessment and management of childhood atopic eczema.

Magnetoelastic standing waves induced in UO2 by microsecond magnetic field pulses.

Magnetoelastic dilatometry of the piezomagnetic antiferromagnet UO2 was performed via the fiber Bragg grating method in magnetic fields up to 150 T generated by a single-turn coil setup. We show that in microsecond timescales, pulsed-magnetic fields excite mechanical resonances at temperatures ranging from 10 to 300 K, in the paramagnetic as well as within the robust antiferromagnetic state of the material. These resonances, which are barely attenuated within the 100-µs observation window, are attributed to the strong magnetoelastic coupling in UO2 combined with the high crystalline quality of the single crystal samples. They compare well with mechanical resonances obtained by a resonant ultrasound technique and superimpose on the known nonmonotonic magnetostriction background. A clear phase shift of π in the lattice oscillations is observed in the antiferromagnetic state when the magnetic field overcomes the piezomagnetic switch field H[Formula: see text] T. We present a theoretical argument that explains this unexpected behavior as a result of the reversal of the antiferromagnetic order parameter at Hc.

How protein engineering has revealed the molecular mechanisms of pore-forming toxins.

Pore-forming proteins are found in prokaryotes, vertebrates, and invertebrates, and when involved in pathogenic processes they are classified as pore-forming toxins (PFTs). The use of gene engineering methods in combination with the information provided by the high-resolution crystal structures of the PFTs have allowed investigators to gain a deep understanding of their pore-forming mechanisms. In this chapter, we discuss how protein engineering has helped us and others to reveal the molecular mechanisms of pore formation by prokaryotic PFTs with an emphasis on our experiences with the cholesterol-dependent cytolysins (CDCs).

Mortality in adolescent trauma: a comparison of children's, mixed and adult major trauma centres.

OBJECTIVE: We aimed to compare adolescent mortality rates between different types of major trauma centre (MTC or level 1; adult, children's and mixed). METHODS: Data were obtained from TARN (Trauma Audit Research Network) from English sites over a 6-year period (2012-2018), with adolescence defined as 10-24.99 years. Results are presented using descriptive statistics. Patient characteristics were compared using the Kruskal-Wallis test with Dunn's post-hoc analysis for pairwise comparison and χ2 test for categorical variables. RESULTS: 21 033 cases met inclusion criteria. Trauma-related 30-day crude mortality rates by MTC type were 2.5% (children's), 4.4% (mixed) and 4.9% (adult). Logistic regression accounting for injury severity, mechanism of injury, physiological parameters and 'hospital ID', resulted in adjusted odds of mortality of 2.41 (95% CI 1.31 to 4.43; p=0.005) and 1.85 (95% CI 1.03 to 3.35; p=0.041) in adult and mixed MTCs, respectively when compared with children's MTCs. In three subgroup analyses the same trend was noted. In adolescents aged 14-17.99 years old, those managed in a children's MTC had the lowest mortality rate at 2.5%, compared with 4.9% in adult MTCs and 4.4% in mixed MTCs (no statistical difference between children's and mixed). In cases of major trauma (Injury Severity Score >15) the adjusted odds of mortality were also greater in the mixed and adult MTC groups when compared with the children's MTC. Median length of stay (LoS) and intensive care unit LoS were comparable for all MTC types. Patients managed in children's MTCs were less likely to have a CT scan (46.2% vs 62.8% mixed vs 64% adult). CONCLUSIONS: Children's MTC have lower crude and adjusted 30-day mortality rates for adolescent trauma. Further research is required in this field to identify the factors that may have influenced these findings.

Fifteen-minute consultation: Drowning in children.

Drowning is a significant cause of childhood morbidity and mortality globally. The underlying mechanisms vary with child development and most are modifiable to public health promotion strategies. This article serves to highlight some of the specific considerations for the clinical management of drowning in children, both prehospital and by the in-hospital paediatric resuscitation team. This includes changes to standard advanced paediatric life support in the presence of hypothermia.

A Key Motif in the Cholesterol-Dependent Cytolysins Reveals a Large Family of Related Proteins.

The cholesterol-dependent cytolysins (CDCs) are bacterial, ß-barrel, pore-forming toxins. A central enigma of the pore-forming mechanism is how completion of the prepore is sensed to initiate its conversion to the pore. We identified a motif that is conserved between the CDCs and a diverse family of nearly 300 uncharacterized proteins present in over 220 species that span at least 10 bacterial and 2 eukaryotic phyla. Except for this motif, these proteins exhibit little similarity to the CDCs at the primary structure level. Studies herein show this motif is a critical component of the sensor that initiates the prepore-to-pore transition in the CDCs. We further show by crystallography, single particle analysis, and biochemical studies of one of these CDC-like (CDCL) proteins from Elizabethkingia anophelis, a commensal of the malarial mosquito midgut, that a high degree of structural similarity exists between the CDC and CDCL monomer structures and both form large oligomeric pore complexes. Furthermore, the conserved motif in the E. anophelis CDCL crystal structure occupies a nearly identical position and makes similar contacts to those observed in the structure of the archetype CDC, perfringolysin O (PFO). This suggests a common function in the CDCs and CDCLs and may explain why only this motif is conserved in the CDCLs. Hence, these studies identify a critical component of the sensor involved in initiating the prepore-to-pore transition in the CDCs, which is conserved in a large and diverse group of distant relatives of the CDCs.IMPORTANCE The cholesterol-dependent cytolysins' pore-forming mechanism relies on the ability to sense the completion of the oligomeric prepore structure and initiate the insertion of the ß-barrel pore from the assembled prepore structure. These studies show that a conserved motif is an important component of the sensor that triggers the prepore-to-pore transition and that it is conserved in a large family of previously unidentified CDC-like proteins, the genes for which are present in a vast array of microbial species that span most terrestrial environments, as well as most animal and human microbiomes. These studies establish the foundation for future investigations that will probe the contribution of this large family of CDC-like proteins to microbial survival and human disease.

Rash as a presenting complaint in a child with COVID-19.

Cutaneous manifestations are becoming increasingly well-documented in adults with COVID-19. There is now also a growing body of literature regarding skin involvement in children, with reports of papulovesicular, petechial and widespread macular and papular lesions, and chilblains (pernio). We describe the case of a 13-year-old boy with confirmed COVID-19 in the United Kingdom who presented with skin findings localized to the plantar aspects of the feet, axillae, and lower limbs. The morphology was predominantly maculopapular but also included petechiae and annular lesions.

Studying social media sentiment using human validated analysis.

The measurement of online sentiment is a developing field in social science and big data research. The methodology from this study provides an analysis of online sentiment using a unique combination of NLP and human validation techniques in order to create net sentiment scores and categorise topics of online conversation. The study focused on measuring the online sentiment of South Africa's major banks (covering almost the entire retail banking industry) over a 12-month period. Through this methodology, firms are able to track shifts in online sentiment (including extreme firestorms) as well as to monitor relevant conversation topics. To date, no published methodology combines the use of big data NLP and human validation in such a structured way.•Microsampling for manual validation of sentiment analysis (both qualitative and quantitative approaches in order to obtain the most accurate results)•Sentiment measurement•Sentiment map.

Discordant molecular tests for acute Graft-Versus-Host Disease after liver transplant: FISHing for the proper diagnosis.

We report cutaneous fluorescent in-situ hybridization (FISH) analysis as a useful test for earlier diagnostic confirmation in a case of acute graft-versus-host disease (GVHD) in a sex-mismatched liver transplant patient compared to the gold standard peripheral blood short tandem repeat chimerism analysis.

Emissions of organic compounds from produced water ponds I: Characteristics and speciation.

We measured fluxes of methane, a suite of non-methane hydrocarbons (C2-C11), light alcohols, and carbon dioxide from oil and gas produced water storage and disposal ponds in Utah (Uinta Basin) and Wyoming (Upper Green River Basin) United States during 2013-2016. In this paper, we discuss the characteristics of produced water composition and air-water fluxes, with a focus on flux chamber measurements. In companion papers, we will (1) report on inverse modeling methods used to estimate emissions from produced water ponds, including comparisons with flux chamber measurements, and (2) discuss the development of mass transfer coefficients to estimate emissions and place emissions from produced water ponds in the context of all regional oil and gas-related emissions. Alcohols (made up mostly of methanol) were the most abundant organic compound group in produced water (91% of total volatile organic concentration, with upper and lower 95% confidence levels of 89 and 93%) but accounted for only 34% (28 to 41%) of total organic compound fluxes from produced water ponds. Non-methane hydrocarbons, which are much less water-soluble than methanol and less abundant in produced water, accounted for the majority of emitted organics. C6-C9 alkanes and aromatics dominated hydrocarbon fluxes, perhaps because lighter hydrocarbons had already volatilized from produced water prior to its arrival in storage or disposal ponds, while heavier hydrocarbons are less water soluble and less volatile. Fluxes of formaldehyde and other carbonyls were low (1% (1 to 2%) of total organic compound flux). The speciation and magnitude of fluxes varied strongly across the facilities measured and with the amount of time water had been exposed to the atmosphere. The presence or absence of ice also impacted fluxes.