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There is an enduring requirement to develop animal models of COVID-19 to assess the efficacy of vaccines and therapeutics that can be used to treat the disease in humans. In this study, six marmosets were exposed to a small particle aerosol (1–3 µm) of SARS-CoV-2 VIC01 that delivered the virus directly to the lower respiratory tract. Following the challenge, marmosets did not develop clinical signs, although a disruption to the normal diurnal temperature rhythm was observed in three out of six animals. Early weight loss and changes to respiratory pattern and activity were also observed, yet there was limited evidence of viral replication or lung pathology associated with infection. There was a robust innate immunological response to infection, which included an early increase in circulating neutrophils and monocytes and a reduction in the proportion of circulating T-cells. Expression of the ACE2 receptor in respiratory tissues was almost absent, but there was ubiquitous expression of TMPRSS2. The results of this study indicate that exposure of marmosets to high concentrations of aerosolised SARS-CoV-2 did not result in the development of clear, reproducible signs of COVID-19.

Background: Inhalational antibiotics have been used effectively to treat chronic diseases such as Pseudomonas aeruginosa infections associated with cystic fibrosis. This approach may enhance treatment options for difficult-to-treat, acute pneumonic diseases. Liposomal encapsulated ciprofloxacin (Lipoquin and/or Apulmiq) has provided protection in murine models of plague, anthrax, Q fever and tularemia. Development of the ability to deliver these drugs to nonhuman primates (NHPs) would enable further extrapolation of the data observed in small animal models of infection to humans. Methods: In this study, the methodology was established to deliver Apulmiq to common marmosets (Callithrix jacchus). Marmosets were anaesthetised with a novel, reversible anaesthetic comprising fentanyl, medetomidine and midazolam (FMM). They were placed into plethysmography tubes with their heads in an exposure chamber. The LC Sprint jet nebuliser or Pari eFlow Rapid nebuliser were used to aerosolise Apulmiq into the exposure chamber. Animals were euthanised after dosing and the concentration of ciprofloxacin was assessed in the plasma and lungs of the animals. Results: Non-compartmental pharmacokinetic analysis determined that a 30 min exposure of drug was required to reach a human-equivalent target dose of 0.8 mg/kg body weight in the lungs. Conclusions: This approach can now be used to assess the efficacy of inhalational liposomal ciprofloxacin in NHP infection models.

Background/Objectives: Q fever, caused by Coxiella burnetii, is typically treated with doxycycline, but its efficacy is limited in chronic cases and may be poorly tolerated. Systemic ciprofloxacin shows limited activity for acute Q fever. However, inhaled liposomal formulations may provide therapeutic benefit. Methods: Two inhaled ciprofloxacin formulations (Lipoquin® and Apulmiq®) were evaluated in an A/J mouse model of Q fever and compared with intraperitoneal ciprofloxacin and oral doxycycline. Initially, pharmacokinetic studies were performed to determine an appropriate dosing regimen for the inhaled ciprofloxacin formulations. A separate cohort of mice were then infected with C. burnetii and treated once daily via nebulisation with Lipoquin or Apulmiq, initiated at 24, 48, or 72 h post-challenge. Clinical signs, weight change, splenomegaly, bacterial burden, and lung histopathology were evaluated. Results: Pharmacokinetic analysis confirmed sustained lung concentrations of inhaled ciprofloxacin, supporting once-daily dosing. Inhaled Lipoquin and Apulmiq significantly reduced clinical signs, weight loss, splenomegaly, and pulmonary bacterial burden compared to untreated controls and doxycycline-treated mice. Histopathology revealed decreased lung inflammation and lesion severity following inhalational dosing. Systemic ciprofloxacin slightly reduced splenic bacterial burden but was less effective in controlling pulmonary infection. Conclusions: Inhaled liposomal ciprofloxacin demonstrated superior protection and reduced respiratory manifestations of Q fever compared to doxycycline and systemic ciprofloxacin. These findings suggest inhaled formulations may represent a viable alternative for the treatment of Q fever pneumonia. Further studies are needed to evaluate clinical applicability and long-term outcomes.

SARS-CoV-2 infection is generally mild or asymptomatic in children but a biological basis for this outcome is unclear. Here we compare antibody and cellular immunity in children (aged 3–11 years) and adults. Antibody responses against spike protein were high in children and seroconversion boosted responses against seasonal Beta-coronaviruses through cross-recognition of the S2 domain. Neutralization of viral variants was comparable between children and adults. Spike-specific T cell responses were more than twice as high in children and were also detected in many seronegative children, indicating pre-existing cross-reactive responses to seasonal coronaviruses. Importantly, children retained antibody and cellular responses 6 months after infection, whereas relative waning occurred in adults. Spike-specific responses were also broadly stable beyond 12 months. Therefore, children generate robust, cross-reactive and sustained immune responses to SARS-CoV-2 with focused specificity for the spike protein. These findings provide insight into the relative clinical protection that occurs in most children and might help to guide the design of pediatric vaccination regimens.SARS-CoV-2 infection is milder in children, but direct comparison with adults is rare. Here the authors show that immune responses are higher in children, retained for 12 months or longer and can neutralize Alpha, Beta and Delta variants.

Background and Objectives: Management of second-trimester placenta accreta spectrum (PAS) is currently center-dependent with minimal evidence-based practices. This study aims to analyze outcomes of hysterectomy as second-trimester active management (AM) versus cesarean hysterectomy as expectant management (EM) in cases of PAS with intraoperative and postoperative outcomes. Materials and Methods: This study is a retrospective case-control study of patients with a pathology-confirmed diagnosis of PAS managed at a single center over 16 years (2005–2020). All cases were diagnosed during the first or second trimester by ultrasonography and managed by the same multidisciplinary team with delivery within the second trimester. Results: Thirty-four patients with PAS were diagnosed and delivered by the second trimester. Of these, (41.1%) elected for active management and 20 (58.9%) for expectant management but ultimately required delivery prior to 28 weeks’ gestation. Baseline demographics were similar between groups. Intraoperatively, no differences were noted in operative time (191.5 vs. 203 min, p = 0.85), blood loss (2300 vs. 2600 cc, p = 0.85), or incidental cystotomy (1 vs. 7, p = 0.10). Postoperative length of stay was similar (3 vs. 3.5 days, p = 0.28), and ICU admission was not statistically different (6 vs. 12, p = 0.48). Conclusions: This retrospective study suggests that when hysterectomy is planned, there is no difference in maternal outcomes and morbidity with an expectant management with cesarean hysterectomy in the second trimester compared to proactive cesarean hysterectomy.

Omicron variants of SARS-CoV-2 are globally dominant and infection rates are very high in children. We measure immune responses following Omicron BA.1/2 infection in children aged 6-14 years and relate this to prior and subsequent SARS-CoV-2 infection or vaccination. Primary Omicron infection elicits a weak antibody response with poor functional neutralizing antibodies. Subsequent Omicron reinfection or COVID-19 vaccination elicits increased antibody titres with broad neutralisation of Omicron subvariants. Prior pre-Omicron SARS-CoV-2 virus infection or vaccination primes for robust antibody responses following Omicron infection but these remain primarily focussed against ancestral variants. Primary Omicron infection thus elicits a weak antibody response in children which is boosted after reinfection or vaccination. Cellular responses are robust and broadly equivalent in all groups, providing protection against severe disease irrespective of SARS-CoV-2 variant. Immunological imprinting is likely to act as an important determinant of long-term humoral immunity, the future clinical importance of which is unknown. The immune responses to SARS CoV-2 infection in children are less well understood than in adults. Here the authors characterise immune responses to newer omicron lineages and relate these to previous infection with earlier lineages of SARS-CoV-2, implicating a reduced immunogenicity from omicron variants and imprinting from previous virus strains.

Background Failure of eruption of the maxillary permanent incisor teeth usually presents in the mixed dentition between the ages of 7 and 9 years. Missing and unerupted maxillary incisors can be regarded as unattractive and have a potentially negative impact on facial and dental aesthetics. The presence of a supernumerary tooth (or odontoma) is commonly responsible for failed eruption or impaction of the permanent maxillary incisors. The primary objective of this trial is to investigate the success of eruption associated with maxillary incisor teeth that have failed to erupt because of a supernumerary tooth in the anterior maxilla. Methods This protocol describes an interventional multicentre two-arm randomised clinical trial. Participants meeting the eligibility criteria will be randomised (unrestricted equal participant allocation [1:1]) to either space creation with an orthodontic appliance, removal of the supernumerary tooth and application of direct orthodontic traction or space creation with an orthodontic appliance, removal of the supernumerary tooth and monitoring. The primary outcome of this trial is to determine the prevalence of successfully erupted maxillary central permanent incisors at 6 months following removal of the supernumerary tooth. Secondary outcome measures include (1) the effect of initial tooth position (assessed radiographically) on time taken for the tooth to erupt, (2) time taken to align the unerupted tooth to the correct occlusal position, (3) gingival aesthetics and (4) changes in the self-reported Oral Health Related-Quality of Life (OHRQoL) (pre-and post-treatment). Discussion There is a lack of high-quality robust prospective studies comparing the effectiveness of interventions to manage this condition. Furthermore, the UK national clinical guidelines have highlighted a lack of definitive treatment protocols for the management of children who present with an unerupted maxillary incisor due to the presence of a supernumerary tooth. The results of this trial will inform future treatment guidelines for the management of this condition in young children. Trial registration ISRCTN Registry ISRCTN12709966 . Registered on 16 June 2022.

Background Paediatric convulsive status epilepticus is the most common neurological emergency presenting to emergency departments. Risks of resultant neurological morbidity and mortality increase with seizure duration. If the seizure fails to stop within defined time-windows, standard care follows an algorithm of stepwise escalation to more intensive treatments, ultimately resorting to induction of general anaesthesia and ventilation. Additionally, ventilatory support may also be required to treat respiratory depression, a common unwanted effect of treatment. There is strong pre-clinical evidence that pH (acid–base balance) is an important determinant of seizure commencement and cessation, with seizures tending to start under alkaline conditions and terminate under acidic conditions. These mechanisms may be particularly important in febrile status epilepticus: prolonged fever-related seizures which predominantly affect very young children. This trial will assess whether imposition of mild respiratory acidosis by manipulation of inhaled medical gas improves response rates to first-line medical treatment. Methods A double-blind, placebo-controlled trial of pH manipulation as an adjunct to standard medical treatment of convulsive status epilepticus in children. The control arm receives standard medical management whilst inhaling 100% oxygen; the active arm receives standard medical management whilst inhaling a commercially available mixture of 95% oxygen, 5% carbon dioxide known as ‘carbogen’. Due to the urgent need to treat the seizure, deferred consent is used. The primary outcome is success of first-line treatment in seizure cessation. Planned subgroup analyses will be undertaken for febrile and non-febrile seizures. Secondary outcomes include rates of induction of general anaesthesia, admission to intensive care, adverse events, and 30-day mortality. Discussion If safe and effective 95% oxygen, 5% carbon dioxide may be an important adjunct in the management of convulsive status epilepticus with potential for pre-hospital use by paramedics, families, and school staff. Trial registration EudraCT: 2021-005367-49. CTA: 17136/0300/001. ISRCTN: 52731862. Registered on July 2022.

Children and adolescents generally experience mild COVID-19. However, those with underlying physical health conditions are at a significantly increased risk of severe disease. Here, we present a comprehensive analysis of antibody and cellular responses in adolescents with severe neuro-disabilities who received COVID-19 vaccination with either ChAdOx1 (n=6) or an mRNA vaccine (mRNA-1273, n=8, BNT162b2, n=1). Strong immune responses were observed after vaccination and antibody levels and neutralisation titres were both higher after two doses. Both measures were also higher after mRNA vaccination and were further enhanced by prior natural infection where one vaccine dose was sufficient to generate peak antibody response. Robust T-cell responses were generated after dual vaccination and were also higher following mRNA vaccination. Early T-cells were characterised by a dominant effector-memory CD4+ T-cell population with a type-1 cytokine signature with additional production of IL-10. Antibody levels were well-maintained for at least 3 months after vaccination and 3 of 4 donors showed measurable neutralisation titres against the Omicron variant. T-cell responses also remained robust, with generation of a central/stem cell memory pool and showed strong reactivity against Omicron spike. These data demonstrate that COVID-19 vaccines display strong immunogenicity in adolescents and that dual vaccination, or single vaccination following prior infection, generate higher immune responses than seen after natural infection and develop activity against Omicron. Initial evidence suggests that mRNA vaccination elicits stronger immune responses than adenoviral delivery, although the latter is also higher than seen in adult populations. COVID-19 vaccines are therefore highly immunogenic in high-risk adolescents and dual vaccination might be able to provide relative protection against the Omicron variant that is currently globally dominant.

Background To date no study has looked at the cost-effectiveness of melatonin for anxiety prior to general anaesthetic in children or young people. The aim of the health economic analysis was to evaluate the within trial cost-effectiveness of melatonin for anxiety in children compared to usual care (midazolam) prior to general anaesthesia in children from an NHS and Personal Social Services perspective. Methods The economic evaluation was undertaken alongside a multicentre randomised controlled trial (MAGIC). Children were individually randomised to receive either melatonin or midazolam for anxiety prior to general anaesthesia. Resource use was collected from case-record forms. Children were followed up at 14 days post-surgery. The main outcome was the incremental cost per successful procedure. The trial was closed early due to recruitment futility, which limited the studies statistical power. Results A total of 100 children received the Investigational Medicinal Product (IMP) treatment, 50 receiving melatonin and 50 receiving midazolam, these were the focus of the health economic analysis. On average, costs over 14 days were lower for those who received melatonin (-£46.20, 95% CI: -£166.14 to £66.74) with a mean incremental difference in procedure success of -0.02 (95% CI –0.08 to 0.004), though there was uncertainty around the results. There was no evidence of either treatment being cost-effective in a cost per QALY analysis using the CHU-9D (-£46.20, 95% CI: -£166.142 to £66.74) with a mean incremental QALY -0.0001 (95% CI –0.0008 to 0.0008). Subgroup analysis was limited to those who underwent head and neck procedures owing to small numbers by subgroup for other procedure types and age group and results were similar to the main analysis. Conclusions This is the first study to examine the cost-effectiveness of melatonin in comparison with midazolam in children. The results were inconclusive showing no evidence that melatonin was more cost-effective than midazolam. The study closed early owing to issues with recruitment, which reduced the studies statistical power, and this has limited the economic analysis. Trial registration Registered with the UK Clinical Study Registry ISRCTN18296119 on 10/01/2019.