Intracranial Empyema in Children: A Single-center Retrospective Case Series.

We conducted a retrospective, observational study of 42 children with intracranial empyema admitted to a pediatric neurosurgical center over a 9-year period. Intracranial empyema is rare, but causes significant morbidity and mortality. Twenty-eight cases had neurosurgical source control, more commonly for subdural collections. Streptococcus anginosus group bacteria are important pathogens in subdural empyema, whose isolation predicts more complicated postoperative courses.

A systematic review of economic evaluations of interventions targeting childhood overweight and obesity.

This systematic review critically appraised and synthesized evidence from economic evaluations of interventions targeting childhood excess weight. We conducted systematic searches in 11 databases from inception to April 19, 2023. Studies were eligible if they evaluated interventions targeting children up to 18 years and the study intervention(s) targeted childhood excess weight or sought to improve diet or physical activity, regardless of the type of economic evaluation or the underpinning study design. We synthesized evidence using narrative synthesis methods. One-hundred fifty-one studies met the eligibility criteria and were classified into three groups based on the intervention approach: prevention-only (13 studies), prevention and treatment (100 studies), and treatment-only (38 studies). The predominant setting and study design differed considerably between the three groups of studies. However, compared with usual care, most interventions were deemed cost-effective. The study participants' ages, sex, and socioeconomic status were crucial to intervention cost-effectiveness. Interventions whose effects were projected beyond childhood, such as bariatric surgery, lower protein infant formula, and home-based general practitioner consultations, tended to be cost-effective. However, cost-effectiveness was sensitive to the assumptions underlying the persistence and intensity of such effects. Our findings can inform future recommendations on the conduct of economic evaluations of interventions targeting childhood overweight and obesity, as well as practice and policy recommendations.

COVID-19 Vaccines: Ensuring Social Justice and Health Equity among Refugees in Africa.

COVID-19 poses a particular threat to refugees in Africa. Overcrowded living conditions and lack of effective sanitation make refugees highly vulnerable to infection. Furthermore, migration has the potential to undermine measures to control viral spread. As a result, vaccination of the refugee community in Africa must be considered key in the vaccination plan to end the worldwide COVID-19 pandemic. Although the WHO has approved vaccines for emergency use worldwide in vulnerable groups through the COVID-19 Vaccines Global Access (COVAX) program, there is a lack of a strategy for achieving vaccination in the African refugee population. A specific strategy for refugee vaccination must be among the top priorities at national, regional, and global levels to ensure all refugees and asylum seekers in African countries have equitable and quality vaccine assistance regardless of displacement, statelessness, and financial hardship. We call on leaders in Africa and worldwide to ensure that refugee vaccination is a priority to protect this highly at-risk population and achieve an end to the current pandemic.

COVID-19 and its threat to refugees in Africa.

Although it is widely accepted that coronavirus disease 2019 (COVID-19) has adversely affected the Global South's most vulnerable refugee communities, they have received little attention. There have been gaps in testing, which is fundamental to treat and isolate patients and make data-driven decisions to protect the refugee community. Therefore, it is imperative to holistically implement policies to curtail COVID-19 in refugee camps to ensure that refugees are safe and protected from the pandemic. Processes for timely diagnosis and treatment, quick isolation and contact tracing are essential to keep refugees safe. Furthermore, it is crucial to encourage protective behaviours and raise awareness about hygiene and social prevention to dampen disease transmission. Refugees in the Global South have been disproportionately affected by the consequences of the COVID-19 pandemic, facing financial hardship and social injustice throughout. Refugees in Africa have also faced threats to their security, being subjected to torture, disappearance, or even killings in their host countries. The pandemic has exposed gender inequalities, with females being the most affected, and health inequities in the refugee community in Africa. There is a need for international organizations like the African Union, United Nations (UN) agencies, non-governmental organizations (NGOs), and other stakeholders to take serious action regarding the refugee situation in Africa. Food aid for refugees in Africa should be increased as quickly as possible and refugees' security must be guaranteed. Of equal importance, there must be justice for the death or disappearance of refugees. It is imperative to end discrimination against refugees and support the promotion of gender equity.

Site-specific conjugation of antifreeze proteins onto polymer-stabilized nanoparticles.

Antifreeze proteins (AFPs) have many potential applications, ranging from cryobiology to aerospace, if they can be incorporated into materials. Here, a range of engineered AFP mutants were prepared and site-specifically conjugated onto RAFT polymer-stabilized gold nanoparticles to generate new hybrid multivalent ice growth inhibitors. Only the SNAP-tagged AFPs lead to potent 'antifreeze' active nanomaterials with His-Tag capture resulting in no activity, showing the mode of conjugation is essential. This versatile strategy will enable the development of multivalent AFPs for translational and fundamental studies.

Multivalent Presentation of Ice Recrystallization Inhibiting Polymers on Nanoparticles Retains Activity.

Poly(vinyl alcohol) (PVA) has emerged as the most potent mimic of antifreeze (glyco)proteins ice recrystallization inhibition (IRI) activity, despite its lack of structural similarities and flexible, rather than rigid, backbone. The precise spacing of hydroxyl groups is hypothesized to enable PVA to recognize the prism planes of ice but not the basal plane, due to hydroxyl pattern matching of the ice surface giving rise to the macroscopic activity. Here, well-defined PVA derived from reversible addition-fragmentation chain-transfer (RAFT) polymerization is immobilized onto gold nanoparticles to enable the impact of nanoscale assembly and confinement on the observed IRI activity. Unlike previous reports using star-branched or bottle-brush PVAs, the nanoparticle-PVA retains all IRI activity compared to polymers in solution. Evidence is presented to show that this is due to the low grafting densities on the particle surface meaning the chains are free to explore the ice faces, rather than being constrained as in star-branched polymers. These results demonstrate a route to develop more functional IRI's and inclusion of metallic particle cores for imaging and associated applications in cryobiology.

Double-Modified Glycopolymers from Thiolactones to Modulate Lectin Selectivity and Affinity.

Multivalent glycomaterials show high affinity toward lectins but are often nonselective as they lack the precise 3-D presentation found in native glycans. Here, thiolactone chemistry is exploited to enable the synthesis of glycopolymers with both a primary binding (galactose) and a variable secondary binding unit in close proximity to each other on the linker. These polymers are used to target the Cholera toxin B subunit, CTxB, inspired by its native branched glycan target, GM-1. The secondary, nonbinding unit was shown to dramatically modulate affinity and selectivity toward the Cholera toxin. These increasingly complex glycopolymers, assembled using accessible chemistry, can help breach the synthetic/biological divide to obtain future glycomimetics.

Multivalent Antimicrobial Polymer Nanoparticles Target Mycobacteria and Gram-Negative Bacteria by Distinct Mechanisms.

Because of the emergence of antimicrobial resistance to traditional small-molecule drugs, cationic antimicrobial polymers are appealing targets. Mycobacterium tuberculosis is a particular problem, with multi- and total drug resistance spreading and more than a billion latent infections globally. This study reports nanoparticles bearing variable densities of poly(dimethylaminoethyl methacrylate) and the unexpected and distinct mechanisms of action this multivalent presentation imparts against Escherichia coli versus Mycobacterium smegmatis (model of M. tuberculosis), leading to killing or growth inhibition, respectively. A convergent "grafting to" synthetic strategy was used to assemble a 50-member nanoparticle library, and using a high-throughput screen identified that only the smallest (2 nm) particles were stable in both saline and complex cell media. Compared with the linear polymers, the nanoparticles displayed two- and eight-fold enhancements in antimicrobial activity against M. smegmatis and E. coli, respectively. Mechanistic studies demonstrated that the antimicrobial particles were bactericidal against E. coli due to rapid disruption of the cell membranes. Conversely, against M. smegmatis the particles did not lyse the cell membrane but rather had a bacteriostatic effect. These results demonstrate that to develop new polymeric antituberculars the widely assumed, broad spectrum, membrane-disrupting mechanism of polycations must be re-evaluated. It is clear that synthetic nanomaterials can engage in more complex interactions with mycobacteria, which we hypothesize is due to the unique cell envelope at the surface of these bacteria.

Synthesis and characterisation of glucose-functional glycopolymers and gold nanoparticles: study of their potential interactions with ovine red blood cells.

Carbohydrate-protein interactions can assist with the targeting of polymer- and nano-delivery systems. However, some potential protein targets are not specific to a single cell type, resulting in reductions in their efficacy due to undesirable non-specific cellular interactions. The glucose transporter 1 (GLUT-1) is expressed to different extents on most cells in the vasculature, including human red blood cells and on cancerous tissue. Glycosylated nanomaterials bearing glucose (or related) carbohydrates, therefore, could potentially undergo unwanted interactions with these transporters, which may compromise the nanomaterial function or lead to cell agglutination, for example. Here, RAFT polymerisation is employed to obtain well-defined glucose-functional glycopolymers as well as glycosylated gold nanoparticles. Agglutination and binding assays did not reveal any significant binding to ovine red blood cells, nor any haemolysis. These data suggest that gluco-functional nanomaterials are compatible with blood, and their lack of undesirable interactions highlights their potential for delivery and imaging applications.