Cytokine Profile in Children with Severe Multisystem Inflammatory Syndrome Related to the Coronavirus Disease 2019.

The multisystem inflammatory syndrome in children (MIS-C) is a novel and concerning entity related to severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection. Although MIS-C has been the subject of intensive research efforts, its pathophysiology and optimal treatment remain elusive. We studied the clinical features, laboratory findings, and immunoinflammatory profiles of seven children prospectively admitted to a pediatric intensive care unit (PICU) during the first wave of the pandemic. All patients had immunoglobulin (Ig)-G against SARS-CoV-2, four of seven patients had both IgM and IgG, and in one of the 7 SARS-CoV-2 was detected in a respiratory sample. All patients received intravenous fluid boluses (median: 15 mL/kg) and norepinephrine. The most common form of respiratory support was supplemental oxygen via nasal cannula. None of the patients needed mechanical ventilation. The cardiovascular system was frequently involved. All patients had an elevated troponin-I (median: 107.3 ng/L). Four out of seven patients had coronary artery abnormalities, and two of seven had both abnormal electrocardiogram (EKG) findings and evidence of left ventricular dysfunction on echocardiogram. Ig levels and complement function were normal. Peripheral blood phenotyping with flow cytometry showed decreased T-cell numbers at the expense of CD8+ T-cells. Cytokine profiling showed a heterogeneous increase in interleukin (IL)-6, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, IL-18, IL-2Ra, IL-10, and IL-1Ra that tended to normalize after treatment. Our study shows that children with MIS-C have elevated plasma levels of pro- and anti-inflammatory cytokines in the acute phase of the disease without other relevant immunologic disturbances. These findings suggest the presence of a mixed antagonist response syndrome (MARS) similar to that present in pediatric sepsis. Combining a meticulous differential diagnosis with cautiously coordinated immunomodulatory therapy and high-quality supportive care can help clinicians avoid causing iatrogenic harm in patients with MIS-C.

Molecular diagnosis of bacteremia in a pediatric intensive care unit: a step forward.

Aim: T2Bacteria® Panel detects six ESKAPE pathogens in around 3.5 h directly in whole blood. Our aim was to compare T2Bacteria with simultaneous blood culture in critically ill children with suspected bloodstream infection. Materials & methods: Retrospective study of critically ill children admitted to our tertiary-care center (2018-2020). Results: A total of 60 patients were recruited, including 63 episodes and 75 T2Bacteria/blood cultures were performed. Overall agreement between T2Bacteria and blood culture was 78.7% with a discordance of 21.3% (16/75 samples). Conclusion: T2Bacteria Panel may be useful in critically ill children providing an accurate and fast diagnosis of bacteremia directly from blood sample and detecting pathogens not recovered in blood cultures.

A Complete In Vitro Toxicological Assessment of the Biological Effects of Cerium Oxide Nanoparticles: From Acute Toxicity to Multi-Dose Subchronic Cytotoxicity Study.

Engineered nanomaterials (ENMs) are of significant relevance due to their unique properties, which have been exploited for widespread applications. Cerium oxide nanoparticles (CeO2-NPs) are one of most exploited ENM in the industry due to their excellent catalytic and multi-enzyme mimetic properties. Thus, the toxicological effects of these ENMs should be further studied. In this study, the acute and subchronic toxicity of CeO2-NPs were assessed. First, an in vitro multi-dose short-term (24 h) toxicological assessment was performed in three different cell lines: A549 and Calu3 were used to represented lung tissue and 3T3 was used as an interstitial tissue model. After that, a sub-chronic toxicity assessment (90 days) of these NPs was carried out on a realistic and well-established reconstituted primary human airway epithelial model (MucilAir™), cultured at the Air-Liquid Interface (ALI), to study the long-term effects of these particles. Results showed minor toxicity of CeO2-NPs in acute exposures. However, in subchronic exposures, cytotoxic and inflammatory responses were observed in the human airway epithelial model after 60 days of exposure to CeO2-NPs. These results suggest that acute toxicity approaches may underestimate the toxicological effect of some ENMs, highlighting the need for subchronic toxicological studies in order to accurately assess the toxicity of ENM and their cumulative effects in organisms.

Fatal outcome of anti-MDA5 juvenile dermatomyositis in a paediatric COVID-19 patient: a case report.

Anti-melanoma differentiation-associated gene 5 juvenile dermatomyositis (anti-MDA5 JDM) is associated with high risk of developing rapidly progressive interstitial lung disease (RP-ILD). Here we report an 11-year-old girl with anti-MDA5 JDM and RP-ILD which led to a fatal outcome, further aggravated by SARS-CoV-2 infection. She was referred to our hospital after being diagnosed with anti-MDA5 JDM and respiratory failure due to RP-ILD. On admission, fibrobronchoscopy with bronchoalveolar lavage (BAL) revealed Pneumocystis jirovecii infection so treatment with intravenous trimethoprim-sulfamethoxazole was initiated. Due to RP-ILD worsening, immunosuppressive therapy was intensified using methylprednisolone pulses, cyclophosphamide, tofacitinib and intravenous immunoglobulin without response. She developed severe hypoxemic respiratory failure, pneumomediastinum and pneumothorax, further complicated with severe RP-ILD and cervical subcutaneous emphysema. Three real-time RT-PCR for SARS-CoV-2 were made with a negative result. In addition, she was complicated with a secondary hemophagocytic lymphohistiocytosis and a fourth real-time PCR for SARS-CoV-2 performed in BAS sample was positive. Despite aggressive treatment of RP-ILD due to anti-MDA5 JDM, there was no improvement of respiratory failure in the following days and patient developed refractory septic shock and died. Anti-MDA5 JDM patients with RP-ILD have a poor prognosis with a high mortality rate. For this reason, intensive immunosuppressive therapy is essential including the use of promising drugs such as tofacitinib. COVID-19 in children with underlying health conditions like anti-MDA5 JDM may still be at risk for disease and severe complications.

Candidemia Diagnosis With T2 Nuclear Magnetic Resonance in a PICU: A New Approach.

OBJECTIVES: Early diagnosis of invasive Candida infections is a challenge for pediatricians, intensivists, and microbiologists. To fill this gap, a new nanodiagnostic method has been developed using manual application of T2 nuclear magnetic resonance to detect Candida species. The aim of this study was to evaluate, prospectively, the usefulness as a tool diagnosis of the T2Candida panel in pediatric patients admitted at the PICU compared with blood culture. DESIGN: This is a prospective, observational, and unicentric study to compare T2Candida results with simultaneous blood cultures for candidemia diagnose. SETTING: This study was carried out in a 1,300-bed tertiary care hospital with a 16-bed medical-surgical PICU. PATIENTS: Sixty-three patients from 0 to 17 years old were enrolled in this study, including those undergoing solid organ transplantation (kidney, liver, pulmonary, multivisceral, intestinal, and heart) and hematopoietic stem cell transplantation. MEASUREMENTS AND MAIN RESULTS: Seven patients were positive by the T2Candida test. Only two of them had the simultaneous positive blood culture. T2Candida yielded more positive results than blood cultures. CONCLUSIONS: T2Candida might be useful for the diagnosis of candidemia in PICUs. The prevalence of candidemia might be underestimated in this pediatric population. The use of this diagnostic tool in these units may help clinicians to start adequate and timely antifungal treatments.

Bedside Breath-Wise Visualization of Bronchospasm by Electrical Impedance Tomography Could Improve Perioperative Patient Safety: A Case Report.

Bronchospasm appears in up to 4% of patients with obstructive lung disease or respiratory infection undergoing general anesthesia. Clinical examination alone may miss bronchospasm. As a consequence, subsequent (mis)treatment and ventilator settings could lead to pulmonary hyperinflation, hypoxia, hypercapnia, hypotension, patient-ventilator asynchrony, volutrauma, or barotrauma. Electrical impedance tomography (EIT), a new noninvasive technique, can potentially identify bronchospasms by determining regional expiratory time constants (τ) for each one of the pixels of a functional EIT image. We present the first clinical case that highlights the potential of breath-wise EIT-based τ images of the lung to quickly identify bronchospasm at the bedside, which could improve perioperative patient management and safety.

Lipidic nanovesicles stabilize suspensions of metal oxide nanoparticles.

We have studied the effect of adding lipid nanovesicles (liposomes) on the aggregation of commercial titanium oxide (TiO2), zinc oxide (ZnO), or cerium oxide (CeO2) nanoparticles (NPs) suspensions in Hepes buffer. Liposomes were prepared with pure phospholipids or mixtures of phospholipids and/or cholesterol. Changes in turbidity were recorded as a function of time, either of metal nanoparticles alone, or for a mixture of nanoparticles and lipidic nanovesicles. Lipid nanovesicles markedly decrease the NPs tendency to sediment irrespective of size or lipid compositions, thus keeping the metal oxide NPs in suspension. Cryo-electron microscopy, fluorescence anisotropy of TMA-DPH and general polarization of laurdan failed to reveal any major effect of the NPs on the lipid bilayer structure or phase state of the lipids. The above data may help in developing studies of the interaction of inhaled particles with lung surfactant lipids and alveolar macrophages.

Cell uptake, intracellular distribution, fate and reactive oxygen species generation of polymer brush engineered CeO(2-x) NPs.

Cerium Oxide nanoparticles (CeO(2-x) NPs) are modified with polymer brushes of negatively charged poly (3-sulfopropylmethacrylate) (PSPM) and positively charged poly (2-(methacryloyloxy)ethyl-trimethylammonium chloride) (PMETAC) by Atom Transfer Radical Polymerisation (ATRP). CeO(2-x) NPs are fluorescently labelled by covalently attaching Alexa Fluor® 488/Fluorescein isothiocyanate to the NP surface prior to polymerisation. Cell uptake, intracellular distribution and the impact on the generation of intracellular Reactive Oxygen Species (ROS) with respect to CeO(2-x) NPs are studied by means of Raman Confocal Microscopy (CRM), Transmission Electron Microscopy (TEM) and Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). PSPM and PMETAC coated CeO(2-x) NPs show slower and less uptake compared to uncoated Brush modified NPs display a higher degree of co-localisation with cell endosomes and lysosomes after 24 h of incubation. They also show higher co-localisation with lipid bodies when compared to unmodified CeO(2-x) NPs. The brush coating does not prevent CeO(2-x) NPs from displaying antioxidant properties.

Cardiac preload responsiveness in children with cardiovascular dysfunction or dilated cardiomyopathy: a multicenter observational study.

OBJECTIVES: To characterize cardiac preload responsiveness in pediatric patients with cardiovascular dysfunction and dilated cardiomyopathy using global end-diastolic volume index, stroke volume index, cardiac index, and extravascular lung water index. DESIGN: Prospective multicenter observational study. SETTING: Medical/surgical PICUs of seven Spanish University Medical Centers. PATIENTS: Seventy-five pediatric patients (42 male, 33 female), median age 36 months (range, 1-207 mo), were divided into three groups: normal cardiovascular status, cardiovascular dysfunction, and dilated cardiomyopathy. INTERVENTIONS: All patients received hemodynamic monitoring with PiCCO2 (Pulsion Medical System SE, Munich, Germany). We evaluated 598 transpulmonary thermodilution sets of measurements. In 40 patients, stroke volume index, cardiac index, and global end-diastolic volume index were measured before and after 66 fluid challenges and loadings to test fluid responsiveness at different preload levels. MEASUREMENTS AND MAIN RESULTS: Global end-diastolic volume versus predicted body surface area exhibits a power-law relationship: Global end-diastolic volume = 488.8·predicted body surface area (r = 0.93). Four levels of cardiac preload were established from the resulting "normal" global end-diastolic volume index (= 488.8·predicted body surface area). Stroke volume index and cardiac index versus global end-diastolic volume index/normal global end-diastolic volume index built using a linear mixed model analysis emulated Frank-Starling curves: in cardiovascular dysfunction group, stroke volume index (geometric mean [95% CI]) was 27 mL/m (24-31 mL/m) at "≤ 0.67 times normal global end-diastolic volume index," 37 mL/m (35-40 mL/m) at "> 0.67 ≤ 1.33 times normal global end-diastolic volume index" (Δ stroke volume index = 35%; p < 0.0001; area under the receiver-operating characteristic curve = 75%), 45 mL/ m (41-49 mL/m) at "> 1.33 ≤ 1.51 times normal global end-diastolic volume index" (Δ stroke volume index = 21%; p < 0.0001; area under the receiver-operating characteristic curve = 73%), and 47 mL/m (43-51 mL/m) at "> 1.51 times normal global end-diastolic volume index" (Δ stroke volume index = 4%; p = 1; area under the receiver-operating characteristic curve = 54%). In dilated cardiomyopathy group, stroke volume index was 21 mL/m (17-26 mL/m) at "> 0.67 ≤ 1.33 times normal global end-diastolic volume index," 27 mL/m (21-34 mL/ m) at "> 1.33 ≤ 1.51 times normal global end-diastolic volume index" (Δ stroke volume index = 29%; p = 0.005; area under the receiver-operating characteristic curve = 64%), and 25 mL/m (20-32 mL/m) at "> 1.51 times normal global end-diastolic volume index" (Δ stroke volume index = -8%; p = 1; area under the receiver-operating characteristic curve = 54%). CONCLUSIONS: This study provides "normal" values for global end-diastolic volume index and limits of cardiac preload responsiveness in pediatric patients with cardiovascular dysfunction and dilated cardiomyopathy: 1.33 times normal global end-diastolic volume index represents the upper limit of patent cardiac preload responsiveness, with the highest expected responsiveness being below 0.67 times normal global end-diastolic volume index. The maximum response of the Frank-Starling relationship and therefore the level of no additional preload reserve is 1.33 to 1.51 times normal global end-diastolic volume index. Above 1.51 times normal global end-diastolic volume index preload responsiveness is unlikely, and the risk of pulmonary edema is maximal.

Fabrication of hybrid graphene oxide/polyelectrolyte capsules by means of layer-by-layer assembly on erythrocyte cell templates.

A novel and facile method was developed to produce hybrid graphene oxide (GO)-polyelectrolyte (PE) capsules using erythrocyte cells as templates. The capsules are easily produced through the layer-by-layer technique using alternating polyelectrolyte layers and GO sheets. The amount of GO and therefore its coverage in the resulting capsules can be tuned by adjusting the concentration of the GO dispersion during the assembly. The capsules retain the approximate shape and size of the erythrocyte template after the latter is totally removed by oxidation with NaOCl in water. The PE/GO capsules maintain their integrity and can be placed or located on other surfaces such as in a device. When the capsules are dried in air, they collapse to form a film that is approximately twice the thickness of the capsule membrane. AFM images in the present study suggest a film thickness of approx. 30 nm for the capsules in the collapsed state implying a thickness of approx. 15 nm for the layers in the collapsed capsule membrane. The polyelectrolytes used in the present study were polyallylamine hydrochloride (PAH) and polystyrenesulfonate sodium salt (PSS). Capsules where characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), dynamic light scattering (DLS) and Raman microscopy, the constituent layers by zeta potential and GO by TEM, XRD, and Raman and FTIR spectroscopies.

Potential impact of metal oxide nanoparticles on the immune system: The role of integrins, L-selectin and the chemokine receptor CXCR4.

The impact of metal oxide nanoparticles (NPs) on the immune system has been studied in vitro using human peripheral blood lymphocytes (PBLs). Metal oxide NPs (ZnO, CeO2, TiO2 and Al2O3) induced changes in the expression levels of adhesion molecules and the C-X-C chemokine receptor type 4 (CXCR4) in these cells. Proliferation studies were carried out with CFSE in response to PHA, finding an increase in T-cell proliferation upon cell exposure to TiO2 and Al2O3 NPs. For ZnO NPs, a decrease in the chemotactic response to SDF-1α was observed. No changes were found in basophil activation and leukocyte oxidative burst after phagocytosis. Despite the absence of cytotoxicity, metal oxide NPs are not inert; they alter the expression levels of adhesion molecules and chemokine receptors, key actors in the immune response, and affect important cell functions such as T-cell proliferative response to mitogens and chemotaxis. FROM THE CLINICAL EDITOR: This study demonstrates the immune-modulating effects of four different metal nanoparticles in a human peripheral blood lymphocyte model system. These effects were clearly present even though these nanoparticles did not display cytotocity in ex vivo experiments.

Spontaneous confocal Raman microscopy--a tool to study the uptake of nanoparticles and carbon nanotubes into cells.

Confocal Raman microscopy as a label-free technique was applied to study the uptake and internalization of poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) and carbon nanotubes (CNTs) into hepatocarcinoma human HepG2 cells. Spontaneous confocal Raman spectra was recorded from the cells exposed to oxidized CNTs and to PLGA NPs. The Raman spectra showed bands arising from the cellular environment: lipids, proteins, nucleic acids, as well as bands characteristic for either PLGA NPs or CNTs. The simultaneous generation of Raman bands from the cell and nanomaterials from the same spot proves internalization, and also indicates the cellular region, where the nanomaterial is located. For PLGA NPs, it was found that they preferentially co-localized with lipid bodies, while the oxidized CNTs are located in the cytoplasm.

Surface engineered Poly(lactide-co-glycolide) nanoparticles for intracellular delivery: uptake and cytotoxicity--a confocal raman microscopic study.

Confocal Raman Microscopy (CRM) is used to study the cell internalization of poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) fabricated by emulsion techniques with either poly(ethylene imine) (PEI) or bovine serum albumin (BSA) as surface stabilizers. HepG2 cells were exposed to PEI and BSA stabilized PLGA NPs. Spontaneous Confocal Raman Spectra taken in one and the same spot of exposed cells showed bands arising from the cellular environment as well as bands characteristic for PLGA, proving that the PLGA NPs have been internalized. It was found that PLGA NPs preferentially colocalize with lipid bodies. The results from Raman spectroscopy are compared with flow cytometry and confocal scanning laser microscopy (CLSM) data. The advantages of CRM as a label-free technique over flow cytometry and CLSM are discussed. Additionally, cell viability studies by means of quick cell counting solution and MTT tests in several cell lines show a generally low toxicity for both PEI and BSA stabilized PLGA NPs, with BSA stabilized PLGA NPs having an even lower toxicity than PEI stabilized.

Layer by layer chitosan/alginate coatings on poly(lactide-co-glycolide) nanoparticles for antifouling protection and Folic acid binding to achieve selective cell targeting.

Polyelectrolyte multilayers (PEMs) composed of two natural polysaccharides-chitosan (Chi) and alginate (Alg) were deposited by Layer by layer (LbL) assembly on top of biocompatible poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs). Folic acid (FA) or FA grafted poly(ethylene glycol) (PEG-FA) were covalently bounded to the PEMs via carbodiimide chemistry. The assembly of biocompatible PEMs was monitored on planar surfaces by means of the quartz crystal microbalance with dissipation (QCM-D) technique and on top of PLGA NPs by means of ζ-potential measurements. BSA was used as model protein to characterize protein adsorption on PEMs. QCM-D showed protein deposition could not be observed on the Chi/Alg multilayer, for both Chitosan and Alginate as top layers. Finally, cellular uptake experiments were carried out by co-culture of HepG2 cells in presence of NPs. Flow Cytometry and confocal laser scanning microscopy (CLSM) were used to investigate the influence of the surface chemistry of the NPs on uptake. For the HepG2 cell line significantly less uptake of PLGA NPs coated with Chi/Alg than the bare NPs was observed but the uptake increased after attachment of FA molecules.

Estado nutricional de bailarinas de ballet clásico, area metropolitana de Costa Rica / Nutritional status of classical ballet dancers, metropolitan area of Costa Rica

El principal objetivo de esta investigación fue determinar el estado nutricional de bailarinas de ballet clásico de las tres academias más importantes de ballet localizadas en el Area Metropolitana de Costa Rica. Se trabajó con 24 bailarinas adultas, 18 a 30 años, de niveles avanzados de ballet. Se registró el consumo de alimentos durante tres días. Se tomaron medidas de talla, peso y pliegues cutáneos. Se recolectaron muestras de sangre para análisis bioquímicos. Se evaluó además la densidad ósea, cadera y lumbar L1, L2, L3, L4, con energía dual de rayos-X. Las actitudes, creencias y riesgo de factores predisponentes a desórdenes alimentarios se evaluaron mediante una entrevista y con la aplicación del Test de Actitudes Alimentarias, EAT-26 e Inventario de Trastornos Alimentarios, EDI. El consumo promedio diario de energía fue considerablemente menor a la recomendación, 1880 Kcal/d más menos 448, y solamente la niacina y la vitamina B6 fueron consumidas en rangos óptimos. La densidad ósea, hemoglobina y hematocrito estuvieron dentro de los rangos de normalidad. Los resultados de este estudio sugieren que las bailarinas con Indice de Masa Corporal, IMC menor igual 20 Kg/m2 tienen dietas más hipocalóricas y mayor riesgo de desórdenes alimentarios. Se necesita investigación en este campo para desarrollar estrategias de educación nutricional que permitan mejorar el estado nutricional y de salud en esta población.

The main objective of the present study was to examine the nutritional status of classic ballet dancers from three of the most important ballet academies located in Metropolitan Area of Costa Rica. Study participants included twenty-four adult females (18 to 30 years old) of advanced ballet level. Threeday food records were collected from each dancer. Height, body weight and skin fold measurements were completed. Blood samples were collected for biochemical analysis. Bone density was measured by dual X-ray energy (hip and lumbar L1, L2, L3, L4). The attitudes, beliefs and risk factors for eating disorders were evaluated by interview and using the Eating Attitudes Test (EAT-26) and Eating Disorder Inventory (EDI). Total energy intake (1880 Kcal/d ± 448.3) was considerably lower than the dietary recommendations and only niacin and vitamin B6 were consumed at optimal levels. Bone density, hemoglobin and hematocrit were within normal ranges. The results of the present study suggest that dancers with Body Mass Index (BMI) ≥ 20 Kg/m2 have more hypocaloric diets and major risk of eating disorders. Future studies are needed to develop strategies to improve the nutritional status of ballet dancers.

Effect of sample heterogeneity on the interpretation of QCM(-D) data: comparison of combined quartz crystal microbalance/atomic force microscopy measurements with finite element method modeling.

A quartz crystal microbalance was integrated into an AFM in order to monitor the adsorption of biomolecules to the resonator surface with both atomic force microscopy and microgravimetry. The comparison between the two techniques allows the fractional coverage of the surface, theta, to be correlated with the frequency shift of the resonator, deltaf. The adsorbed material was ferritin, which is a spherical protein with a diameter of approximately 12 nm. Even ata coverage below 50%, the protein layer exhibits Sauerbrey-like behavior, meaning that the magnitude in the frequency shift [deltaf] much exceeds the shift in bandwidth and that the normalized frequency shift, deltaf/n (n the overtone order), is similar on the different overtones. The relation between coverage and frequency shift was found to be nonlinear. In order to model this situation, we performed finite element method calculations based on the incompressible Navier-Stokes equation. The comparison between the model and the experiment suggests that the deformation of the protein upon adsorption is small. For low coverage, the volume of the trapped solvent exceeds the volume of the adsorbate itself. The ratio of the two decreases with increasing coverage. This is the cause of the experimentally observed nonlinear relationship between the surface coverage and frequency shift. Comparing frequency shifts at different overtones, one finds that deltaf/n slightly decreases with overtone order. Such a behavior is typically attributed to softness. The model shows that, for the adsorbed spheres, this apparent softness arises through a rocking motion of the spheres at the surface instead of the shear deformation. Also, there is a hydrodynamic contribution (related to roughness) to the overtone dependence of deltaf/n.