Predicting CD4 T-Cell Reconstitution Following Pediatric Hematopoietic Stem Cell Transplantation

Hematopoietic stem cell transplantation (HSCT) is an increasingly common treatment for children with a range of hematological disorders. Conditioning with cytotoxic chemotherapy and total body irradiation leaves patients severely immunocompromised. T‐cell reconstitution can take several years due to delayed restoration of thymic output. Understanding T‐cell reconstitution in children is complicated by normal immune system maturation, heterogeneous diagnoses, and sparse uneven sampling due to the long time spans involved. We describe here a mechanistic mathematical model for CD4 T‐cell immune reconstitution following pediatric transplantation. Including relevant biology and using mixed‐effects modeling allowed the factors affecting reconstitution to be identified. Bayesian predictions for the long‐term reconstitution trajectories of individual children were then obtained using early post‐transplant data. The model was developed using data from 288 children; its predictive ability validated on data from a further 75 children, with long‐term reconstitution predicted accurately in 81% of the patients.

Pulmonary artery perforation and coronary air embolism-two fatal outcomes in percutaneous left atrial appendage occlusion

Percutaneous left atrial appendage (LAA) closure is a routinely performed method to reduce the risk of stroke in patients suffering from atrial fibrillation, when an oral anticoagulation is no longer indicated due to relevant bleeding complications. Currently, the Amplatzer Amulet and the Watchman system are two equally used systems. While there is an acute success rate of more than 95 per cent for this intervention, several minor and major complications such as pericardial effusions, air embolism, vascular lesions in proximity to the heart or even death can occur. Here, we report two cases of very rare fatal outcomes in percutaneous LAA occlusion. Eight hours after deployment of an Amplatzer Amulet a patient died, after the pulmonary trunk was perforated by a hook of the occluder device causing pericardial tamponade. In the second case during final radiological position control of the deployed Watchman occluder air was injected accidentally. The patient immediately died due to coronary air embolism. Forensic autopsies are necessary to solve the cause and manner of death, to evaluate and develop medical devices and to rule out medical malpractice. Thus, a close collaboration of legal medicine and the various cardiologic departments is proposed.

Inflammatory Cytokines, Endothelial Function, and Chronic Allograft Vasculopathy in Children: An Investigation of the Donor and Recipient Vasculature After Heart Transplantation

Chronic allograft vasculopathy (CAV) limits the lifespan of pediatric heart transplant recipients. We investigated blood markers of inflammation, endothelial dysfunction, and damage to both the native and transplanted vasculature in children after heart transplantation. Serum samples were taken from pediatric heart transplant recipients for markers of inflammation and endothelial activation. The systemic vasculature was investigated using brachial artery flow-mediated dilatation and carotid artery intima-medial hyperplasia. CAV was investigated using intravascular ultrasound. Mean intima-media thickness (mIMT) > 0.5 mm was used to define significant CAV. Forty-eight children (25 male) aged 8-18 years were enrolled in the study. Patients were a median (interquartile range) 4.1 (2.2-8.7) years after transplant. Patients had increased levels of circulating IL6 (3.86 [2.84-4.95] vs. 1.66 [1.22-2.63] p < 0.0001), vascular cell adhesion molecule 1 (539 [451-621] vs. 402 [342-487] p < 0.001), intracellular adhesion molecule 1 305 (247-346) vs. 256 (224-294) p = 0.002 and thrombomodulin (7.1 [5.5-8.1] vs. 3.57 [3.03-4.71] p < 0.0001) and decreased levels of tumor necrosis factor-α, E selectin, and P selectin, compared with controls. The systemic vasculature was unaffected. Patients with severe CAV had raised serum von Willebrand factor and decreased serum thrombomodulin. Posttransplant thrombomodulin levels are elevated after transplant but significantly lower in those with mIMT > 0.5 mm. This suggests that subclinical inflammation is present and that natural anticoagulant/thrombomodulin activity is important after transplant.

Correlation of p-doping in CVD Graphene with Substrate Surface Charges

Correlations between the level of p-doping exhibited in large area chemical vapour deposition (CVD) graphene field effect transistor structures (gFETs) and residual charges created by a variety of surface treatments to the silicon dioxide (SiO2) substrates prior to CVD graphene transfer are measured. Beginning with graphene on untreated thermal oxidised silicon, a minimum conductivity (σ(min)) occurring at gate voltage V(g) = 15 V (Dirac Point) is measured. It was found that more aggressive treatments (O2 plasma and UV Ozone treatments) further increase the gate voltage of the Dirac point up to 65 V, corresponding to a significant increase of the level of p-doping displayed in the graphene. An electrowetting model describing the measured relationship between the contact angle (θ) of a water droplet applied to the treated substrate/graphene surface and an effective gate voltage from a surface charge density is proposed to describe biasing of V(g) at σ(min) and was found to fit the measurements with multiplication of a correction factor, allowing effective non-destructive approximation of substrate added charge carrier density using contact angle measurements.

Cardiovascular status after Kawasaki disease in the UK

OBJECTIVE

Kawasaki disease (KD) is an acute vasculitis that causes coronary artery aneurysms (CAA) in young children. Previous studies have emphasised poor long-term outcomes for those with severe CAA. Little is known about the fate of those without CAA or patients with regressed CAA. We aimed to study long-term cardiovascular status after KD by examining the relationship between coronary artery (CA) status, endothelial injury, systemic inflammatory markers, cardiovascular risk factors (CRF), pulse-wave velocity (PWV) and carotid intima media thickness (cIMT) after KD.

METHODS

Circulating endothelial cells (CECs), endothelial microparticles (EMPs), soluble cell-adhesion molecules cytokines, CRF, PWV and cIMT were compared between patients with KD and healthy controls (HC). CA status of the patients with KD was classified as CAA present (CAA+) or absent (CAA-) according to their worst-ever CA status. Data are median (range).

RESULTS

Ninety-two KD subjects were studied, aged 11.9 years (4.3-32.2), 8.3 years (1.0-30.7) from KD diagnosis. 54 (59%) were CAA-, and 38 (41%) were CAA+. There were 51 demographically similar HC. Patients with KD had higher CECs than HC (p=0.00003), most evident in the CAA+ group (p=0.00009), but also higher in the CAA- group than HC (p=0.0010). Patients with persistent CAA had the highest CECs, but even those with regressed CAA had higher CECs than HC (p=0.011). CD105 EMPs were also higher in the KD group versus HC (p=0.04), particularly in the CAA+ group (p=0.02), with similar findings for soluble vascular cell adhesion molecule 1 and soluble intercellular adhesion molecule 1. There was no difference in PWV, cIMT, CRF or in markers of systemic inflammation in the patients with KD (CAA+ or CAA-) compared with HC.

CONCLUSIONS

Markers of endothelial injury persist for years after KD, including in a subset of patients without CAA.

Influenza virus survival in aerosols and estimates of viable virus loss resulting from aerosolization and air-sampling

Using a Collison nebulizer, aerosols of influenza (A/Udorn/307/72 H3N2) were generated within a controlled experimental chamber, from known starting virus concentrations. Air samples collected after variable suspension times were tested quantitatively using both plaque and polymerase chain reaction assays, to compare the proportion of viable virus against the amount of detectable viral RNA. These experiments showed that whereas influenza RNA copies were well preserved, the number of viable viruses decreased by a factor of 10(4)-10(5). This suggests that air-sampling studies for assessing infection control risks that detect only influenza RNA may greatly overestimate the amount of viable virus available to cause infection.

The EPIICAL project: an emerging global collaboration to investigate immunotherapeutic strategies in HIV-infected children

The EPIICAL (Early-treated Perinatally HIV-infected Individuals: Improving Children's Actual Life with Novel Immunotherapeutic Strategies) project arises from the firm belief that perinatally infected children treated with suppressive antiretroviral therapy (ART) from early infancy represent the optimal population model in which to study novel immunotherapeutic strategies aimed at achieving ART-free remission. This is because HIV-infected infants treated within 2-3 months of life have a much reduced viral reservoir size, and rarely show HIV-specific immunity but preserve normal immune development. The goal of EPIICAL is the establishment of an international collaboration to develop a predictive platform using this model to select promising HIV therapeutic vaccine candidates, leading to prioritisation or deprioritisation of novel immunotherapeutic strategies. To establish this platform, the EPIICAL Consortium aims to: develop predictive models of virological and immunological dynamics associated with response to early ART and to treatment interruption using available data from existing cohorts/studies of early-treated perinatally HIV-infected children; optimise methodologies to better characterise immunological, virological and genomic correlates/profiles associated with viral control; test novel immunotherapeutic strategies using in vivo proof-of-concept (PoC) studies with the aim of inducing virological, immunological and transcriptomic correlates/profiles equivalent to those defined by the predictive model. This approach will strengthen the capacity for discovery, development and initial testing of new therapeutic vaccine strategies through the integrated efforts of leading international scientific groups, with the aim of improving the health of HIV-infected individuals.

[Implantable cardioverter-defibrillator at the end of life]

Brady- and tachyarrhythmias at the end of life are common observations. Implantable cardioverter-defibrillators answer with antibrady and antitachycardia pacing, which will not be associated with any complaints of the dying patient. In contrast, defibrillation and cardioversion shocks are extremely painful. Therefore shocks should be inactivated at the end of life. Family doctors, internists, emergency physicians and paramedics are unable to inactivate shocks. Deactivation of shocks at the end of life is not comparable to euthanasia or assisted suicide, but allow the patient to die at the end of an uncurable endstage disease. Deactivation of shocks should be discussed with the patient before initial implantation of the devices. The precise moment of the inactivation at the end of life should be discussed with patients and relatives. There is no common recommendation for the time schedule of this decision; therefore it should be based on the individual situation of the patient. Emergency health care physicians need magnets and sufficient information to inactivate defibrillators. The wishes of the patient have priority in the decision process and should be written in the patient's advance directive, which must be available in the final situation. However the physician must not necessarily follow every wish of the patient. As long as the laws in the European Union are not uniform, German recommendations are needed.

No evidence of transfusion transmission of Adenovirus and Epstein-Barr virus infections in paediatric recipients post-bone marrow transplant

Adenovirus and Epstein-Barr virus can cause significant morbidity and mortality in paediatric patients post-bone marrow transplant. The source of infection is thought to be either reactivation of latent viruses or primary infection. We have investigated whether transfusion of blood components from viraemic donors could provide a route of primary infection in these patients and sought the prevalence of viraemia in the blood donor population from England. In 32 linked donor/recipient samples and 300 unselected blood donors, we found no evidence to suggest that these infections in paediatric bone marrow transplant recipients had been acquired from transfused blood components.

Paediatric European Network for Treatment of AIDS (PENTA) guidelines for treatment of paediatric HIV-1 infection 2015: optimizing health in preparation for adult life

The 2015 Paediatric European Network for Treatment of AIDS (PENTA) guidelines provide practical recommendations on the management of HIV‐1 infection in children in Europe and are an update to those published in 2009. Aims of treatment have progressed significantly over the last decade, moving far beyond limitation of short‐term morbidity and mortality to optimizing health status for adult life and minimizing the impact of chronic HIV infection on immune system development and health in general. Additionally, there is a greater need for increased awareness and minimization of long‐term drug toxicity. The main updates to the previous guidelines include: an increase in the number of indications for antiretroviral therapy (ART) at all ages (higher CD4 thresholds for consideration of ART initiation and additional clinical indications), revised guidance on first‐ and second‐line ART recommendations, including more recently available drug classes, expanded guidance on management of coinfections (including tuberculosis, hepatitis B and hepatitis C) and additional emphasis on the needs of adolescents as they approach transition to adult services. There is a new section on the current ART ‘pipeline’ of drug development, a comprehensive summary table of currently recommended ART with dosing recommendations. Differences between PENTA and current US and World Health Organization guidelines are highlighted and explained.

Term and preterm labour are associated with distinct microbial community structures in placental membranes which are independent of mode of delivery

Infection is considered a possible trigger for preterm labour, supported by evidence showing the presence of bacteria in the placenta and placental membranes from preterm births. In this study, 16S rDNA pyrosequencing was used to identify bacteria in placental membranes. Caesarean sections and vaginal deliveries at term were found to harbour common genera. Mycoplasma hominis, Aerococcus christensenii, Gardnerella vaginalis and Fusobacterium nucleatum were either only present in preterm membranes or in greater abundance than at term. These data support previous studies that used either targeted qPCR or broad-range 16S rDNA PCR and cloning but not a recent microbiome analysis of placental tissue using high-throughput sequencing.

Bildung von Amidophosphaten und Amidophosphorsäure aus N-Methylcarbamoylphosphaten / Formation of Amidophosphates and Amidophosphoric Acid from N-Methylcarbamoyl Phosphates

The synthesis of various amidophosphates can be readily accomplished in aqueous solutions by the reaction of amines with solutions of sodium, potassium or ammonium N-methylcarbamoyl phosphate, prepared by the reaction of methylisocyanate with the corresponding hydrogen phosphates. Procedures for the synthesis of NH4[O3PNH3] and Ca[O3PNH2CH3]2 · 4 H2O are described in detail.